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Fasimoye R, Dong W, Nirujogi RS, Rawat ES, Iguchi M, Nyame K, Phung TK, Bagnoli E, Prescott AR, Alessi DR, Abu-Remaileh M. Golgi-IP, a tool for multimodal analysis of Golgi molecular content. Proc Natl Acad Sci U S A 2023; 120:e2219953120. [PMID: 37155866 PMCID: PMC10193996 DOI: 10.1073/pnas.2219953120] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Accepted: 04/05/2023] [Indexed: 05/10/2023] Open
Abstract
The Golgi is a membrane-bound organelle that is essential for protein and lipid biosynthesis. It represents a central trafficking hub that sorts proteins and lipids to various destinations or for secretion from the cell. The Golgi has emerged as a docking platform for cellular signaling pathways including LRRK2 kinase whose deregulation leads to Parkinson disease. Golgi dysfunction is associated with a broad spectrum of diseases including cancer, neurodegeneration, and cardiovascular diseases. To allow the study of the Golgi at high resolution, we report a rapid Golgi immunoprecipitation technique (Golgi-IP) to isolate intact Golgi mini-stacks for subsequent analysis of their content. By fusing the Golgi-resident protein TMEM115 to three tandem HA epitopes (GolgiTAG), we purified the Golgi using Golgi-IP with minimal contamination from other compartments. We then established an analysis pipeline using liquid chromatography coupled with mass spectrometry to characterize the human Golgi proteome, metabolome, and lipidome. Subcellular proteomics confirmed known Golgi proteins and identified proteins not previously associated with the Golgi. Metabolite profiling established the human Golgi metabolome and revealed the enrichment of uridine-diphosphate (UDP) sugars and their derivatives, which is consistent with their roles in protein and lipid glycosylation. Furthermore, targeted metabolomics validated SLC35A2 as the subcellular transporter for UDP-hexose. Finally, lipidomics analysis showed that phospholipids including phosphatidylcholine, phosphatidylinositol, and phosphatidylserine are the most abundant Golgi lipids and that glycosphingolipids are enriched in this compartment. Altogether, our work establishes a comprehensive molecular map of the human Golgi and provides a powerful method to study the Golgi with high precision in health and disease.
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Affiliation(s)
- Rotimi Fasimoye
- Medical Research Council Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, DundeeDD1 5EH, United Kingdom
- Aligning Science Across Parkinson’s Collaborative Research Network, Chevy Chase, MD20815
| | - Wentao Dong
- Aligning Science Across Parkinson’s Collaborative Research Network, Chevy Chase, MD20815
- Department of Chemical Engineering, Stanford University, Stanford, CA94305
- Department of Genetics, Stanford University, Stanford, CA94305
- The Institute for Chemistry, Engineering & Medicine for Human Health, Stanford University, Stanford, CA94305
| | - Raja S. Nirujogi
- Medical Research Council Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, DundeeDD1 5EH, United Kingdom
- Aligning Science Across Parkinson’s Collaborative Research Network, Chevy Chase, MD20815
| | - Eshaan S. Rawat
- Aligning Science Across Parkinson’s Collaborative Research Network, Chevy Chase, MD20815
- Department of Chemical Engineering, Stanford University, Stanford, CA94305
- Department of Genetics, Stanford University, Stanford, CA94305
- The Institute for Chemistry, Engineering & Medicine for Human Health, Stanford University, Stanford, CA94305
| | - Miharu Iguchi
- Aligning Science Across Parkinson’s Collaborative Research Network, Chevy Chase, MD20815
- Department of Chemical Engineering, Stanford University, Stanford, CA94305
- Department of Genetics, Stanford University, Stanford, CA94305
- The Institute for Chemistry, Engineering & Medicine for Human Health, Stanford University, Stanford, CA94305
| | - Kwamina Nyame
- Aligning Science Across Parkinson’s Collaborative Research Network, Chevy Chase, MD20815
- Department of Chemical Engineering, Stanford University, Stanford, CA94305
- Department of Genetics, Stanford University, Stanford, CA94305
- The Institute for Chemistry, Engineering & Medicine for Human Health, Stanford University, Stanford, CA94305
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA94305
| | - Toan K. Phung
- Medical Research Council Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, DundeeDD1 5EH, United Kingdom
- Aligning Science Across Parkinson’s Collaborative Research Network, Chevy Chase, MD20815
| | - Enrico Bagnoli
- Medical Research Council Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, DundeeDD1 5EH, United Kingdom
- Aligning Science Across Parkinson’s Collaborative Research Network, Chevy Chase, MD20815
| | - Alan R. Prescott
- Dundee Imaging Facility, School of Life Sciences, University of Dundee, DundeeDD1 5EH, United Kingdom
| | - Dario R. Alessi
- Medical Research Council Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, DundeeDD1 5EH, United Kingdom
- Aligning Science Across Parkinson’s Collaborative Research Network, Chevy Chase, MD20815
| | - Monther Abu-Remaileh
- Aligning Science Across Parkinson’s Collaborative Research Network, Chevy Chase, MD20815
- Department of Chemical Engineering, Stanford University, Stanford, CA94305
- Department of Genetics, Stanford University, Stanford, CA94305
- The Institute for Chemistry, Engineering & Medicine for Human Health, Stanford University, Stanford, CA94305
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2
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Rousseau S, Papoutsopoulou M, Symons A, Cook D, Lucocq JM, Prescott AR, O'Garra A, Ley SC, Cohen P. Correction: TPL2-mediated activation of ERK1 and ERK2 regulates the processing of pre-TNFα in LPS-stimulated macrophages. J Cell Sci 2022; 135:280541. [DOI: 10.1242/jcs.260708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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3
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Kalogeropulou AF, Purlyte E, Tonelli F, Lange SM, Wightman M, Prescott AR, Padmanabhan S, Sammler E, Alessi DR. Impact of 100 LRRK2 variants linked to Parkinson's disease on kinase activity and microtubule binding. Biochem J 2022; 479:1759-1783. [PMID: 35950872 PMCID: PMC9472821 DOI: 10.1042/bcj20220161] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 08/01/2022] [Accepted: 08/11/2022] [Indexed: 11/17/2022]
Abstract
Mutations enhancing the kinase activity of leucine-rich repeat kinase-2 (LRRK2) cause Parkinson's disease (PD) and therapies that reduce LRRK2 kinase activity are being tested in clinical trials. Numerous rare variants of unknown clinical significance have been reported, but how the vast majority impact on LRRK2 function is unknown. Here, we investigate 100 LRRK2 variants linked to PD, including previously described pathogenic mutations. We identify 23 LRRK2 variants that robustly stimulate kinase activity, including variants within the N-terminal non-catalytic regions (ARM (E334K, A419V), ANK (R767H), LRR (R1067Q, R1325Q)), as well as variants predicted to destabilize the ROC:CORB interface (ROC (A1442P, V1447M), CORA (R1628P) CORB (S1761R, L1795F)) and COR:COR dimer interface (CORB (R1728H/L)). Most activating variants decrease LRRK2 biomarker site phosphorylation (pSer935/pSer955/pSer973), consistent with the notion that the active kinase conformation blocks their phosphorylation. We conclude that the impact of variants on kinase activity is best evaluated by deploying a cellular assay of LRRK2-dependent Rab10 substrate phosphorylation, compared with a biochemical kinase assay, as only a minority of activating variants (CORB (Y1699C, R1728H/L, S1761R) and kinase (G2019S, I2020T, T2031S)), enhance in vitro kinase activity of immunoprecipitated LRRK2. Twelve variants including several that activate LRRK2 and have been linked to PD, suppress microtubule association in the presence of a Type I kinase inhibitor (ARM (M712V), LRR (R1320S), ROC (A1442P, K1468E, S1508R), CORA (A1589S), CORB (Y1699C, R1728H/L) and WD40 (R2143M, S2350I, G2385R)). Our findings will stimulate work to better understand the mechanisms by which variants impact biology and provide rationale for variant carrier inclusion or exclusion in ongoing and future LRRK2 inhibitor clinical trials.
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Affiliation(s)
- Alexia F. Kalogeropulou
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dow Street, Dundee, U.K
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, U.S.A
| | - Elena Purlyte
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dow Street, Dundee, U.K
| | - Francesca Tonelli
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dow Street, Dundee, U.K
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, U.S.A
| | - Sven M. Lange
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dow Street, Dundee, U.K
| | - Melanie Wightman
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dow Street, Dundee, U.K
| | - Alan R. Prescott
- Dundee Imaging Facility, School of Life Sciences, University of Dundee, Dundee DD1 5EH, U.K
| | | | - Esther Sammler
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dow Street, Dundee, U.K
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, U.S.A
- Molecular and Clinical Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee DD1 9SY, U.K
| | - Dario R. Alessi
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dow Street, Dundee, U.K
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, U.S.A
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4
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Gulyurtlu S, Magon MS, Guest P, Papavasiliou PP, Morrison KD, Prescott AR, Sleeman JE. Condensation properties of stress granules and processing bodies are compromised in Myotonic Dystrophy Type 1. Dis Model Mech 2022; 15:276177. [PMID: 35642886 PMCID: PMC9366894 DOI: 10.1242/dmm.049294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 05/23/2022] [Indexed: 11/26/2022] Open
Abstract
RNA regulation in mammalian cells requires complex physical compartmentalisation, using structures thought to be formed by liquid-liquid phase separation. Disruption of these structures is implicated in numerous degenerative diseases. Myotonic dystrophy type 1 (DM1) is a multi-systemic trinucleotide repeat disorder resulting from an expansion of nucleotides CTG (CTGexp) in the DNA encoding DM1 protein kinase (DMPK). The cellular hallmark of DM1 is the formation of nuclear foci that contain expanded DMPK RNA (CUGexp) (with thymine instead of uracil). We report here the deregulation of stress granules (SGs) and processing bodies (P-bodies), two cytoplasmic structures key for mRNA regulation, in cell culture models of DM1. Alterations to the rates of formation and dispersal of SGs suggest an altered ability of cells to respond to stress associated with DM1, while changes to the structure and dynamics of SGs and P-bodies suggest that a widespread alteration to the biophysical properties of cellular structures is a consequence of the presence of CUGexp RNA. Summary: Validation of an inducible model of myotonic dystrophy type 1 that shows altered cellular stress responses. These involve phase-separated cellular structures also implicated in other degenerative conditions.
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Affiliation(s)
- Selma Gulyurtlu
- Biomolecular Sciences Research Complex, University of St Andrews, North Haugh, St Andrews, Fife, KY16 9ST, UK
| | - Monika S Magon
- Biomolecular Sciences Research Complex, University of St Andrews, North Haugh, St Andrews, Fife, KY16 9ST, UK
| | - Patrick Guest
- Biomolecular Sciences Research Complex, University of St Andrews, North Haugh, St Andrews, Fife, KY16 9ST, UK
| | - Panagiotis P Papavasiliou
- Biomolecular Sciences Research Complex, University of St Andrews, North Haugh, St Andrews, Fife, KY16 9ST, UK
| | - Kim D Morrison
- Biomolecular Sciences Research Complex, University of St Andrews, North Haugh, St Andrews, Fife, KY16 9ST, UK
| | - Alan R Prescott
- School of Life Science, University of Dundee, Dundee, DD1 5EH, UK
| | - Judith E Sleeman
- Biomolecular Sciences Research Complex, University of St Andrews, North Haugh, St Andrews, Fife, KY16 9ST, UK
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5
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Hoxhaj G, Najafov A, Toth R, Campbell DG, Prescott AR, MacKintosh C. Publisher's Note: ZNRF2 is released from membranes by growth factors and, together with ZNRF1, regulates the Na+/K+ATPase. J Cell Sci 2022; 135:jcs259936. [PMID: 35267011 PMCID: PMC11034869 DOI: 10.1242/jcs.259936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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6
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Petrova T, Bennett K, Nanda S, Strickson S, Scudamore CL, Prescott AR, Cohen P. Why are the phenotypes of TRAF6 knock-in and TRAF6 knock-out mice so different? PLoS One 2022; 17:e0263151. [PMID: 35157702 PMCID: PMC8843210 DOI: 10.1371/journal.pone.0263151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 01/12/2022] [Indexed: 11/30/2022] Open
Abstract
The expression of TNF-Receptor Associated Factor 6 (TRAF6) is essential for many physiological processes. Here we studied the phenotype of TRAF6[L74H] knock-in mice which are devoid of TRAF6 E3 ligase activity in every cell of the body, but express normal levels of the TRAF6 protein. Remarkably, TRAF6[L74H] mice have none of the phenotypes seen in TRAF6 KO mice. Instead TRAF6[L74H] mice display an entirely different phenotype, exhibiting autoimmunity, and severe inflammation of the skin and modest inflammation of the liver and lungs. Similar to mice with a Treg-specific knockout of TRAF6, or mice devoid of TRAF6 in all T cells, the CD4+ and CD8+ T cells in the spleen and lymph nodes displayed an activated effector memory phenotype with CD44high/CD62Llow expression on the cell surface. In contrast, T cells from WT mice exhibited the CD44low/CD62Lhigh phenotype characteristic of naïve T cells. The onset of autoimmunity and autoinflammation in TRAF6[L74H] mice (two weeks) was much faster than in mice with a Treg-specific knockout of TRAF6 or lacking TRAF6 expression in all T cells (2-3 months) and we discuss whether this may be caused by secondary inflammation of other tissues. The distinct phenotypes of mice lacking TRAF6 expression in all cells appears to be explained by their inability to signal via TNF Receptor Superfamily members, which does not seem to be impaired significantly in TRAF6[L74H] mice.
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Affiliation(s)
- Tsvetana Petrova
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Kyle Bennett
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, United Kingdom
- Division of Cell Signalling, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Sambit Nanda
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Sam Strickson
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | | | - Alan R. Prescott
- Dundee Imaging Facility and Division of Cell Signalling and Immunology, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Philip Cohen
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, United Kingdom
- * E-mail:
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7
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Wu W, Lois N, Prescott AR, Brown AP, Van Gerwen V, Tassignon MJ, Richards SA, Saunter CD, Jarrin M, Quinlan RA. The importance of the epithelial fibre cell interface to lens regeneration in an in vivo rat model and in a human bag-in-the-lens (BiL) sample. Exp Eye Res 2021; 213:108808. [PMID: 34762932 DOI: 10.1016/j.exer.2021.108808] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 10/20/2021] [Accepted: 10/22/2021] [Indexed: 12/13/2022]
Abstract
Human lens regeneration and the Bag-in-the-Lens (BIL) surgical treatment for cataract both depend upon lens capsule closure for their success. Our studies suggest that the first three days after surgery are critical to their long-term outcomes. Using a rat model of lens regeneration, we evidenced lens epithelial cell (LEC) proliferation increased some 50 fold in the first day before rapidly declining to rates observed in the germinative zone of the contra-lateral, un-operated lens. Cell multi-layering at the lens equator occurred on days 1 and 2, but then reorganised into two discrete layers by day 3. E- and N-cadherin expression preceded cell polarity being re-established during the first week. Aquaporin 0 (AQP0) was first detected in the elongated cells at the lens equator at day 7. Cells at the capsulotomy site, however, behaved very differently expressing the epithelial mesenchymal transition (EMT) markers fibronectin and alpha-smooth muscle actin (SMA) from day 3 onwards. The physical interaction between the apical surfaces of the anterior and posterior LECs from day 3 after surgery preceded cell elongation. In the human BIL sample fibre cell formation was confirmed by both histological and proteome analyses, but the cellular response is less ordered and variable culminating in Soemmerring's ring (SR) formation and sometimes Elschnig's pearls. This we evidence for lenses from a single patient. No bow region or recognisable epithelial-fibre cell interface (EFI) was evident and consequently the fibre cells were disorganised. We conclude that lens cells require spatial and cellular cues to initiate, sustain and produce an optically functional tissue in addition to capsule integrity and the EFI.
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Affiliation(s)
- Weiju Wu
- Department of Biosciences, South Road, Durham University, Durham, DH1 3LE, England, UK
| | - Noemi Lois
- Wellcome-Wolfson Institute for Experimental Medicine, Queens University Belfast, 97 Lisburn Rd, Belfast, BT9 7BL, Northern Ireland, UK.
| | - Alan R Prescott
- Dundee Imaging Facility & Division of Cell Signalling and Immunology, School of Life Sciences, University of Dundee, Dundee, DD1 5EH, Scotland, UK
| | - Adrian P Brown
- Department of Biosciences, South Road, Durham University, Durham, DH1 3LE, England, UK
| | - Veerle Van Gerwen
- Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
| | - Marie-José Tassignon
- Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium; Department of Ophthalmology, Antwerp University Hospital, Edegem, Belgium
| | - Shane A Richards
- School of Natural Sciences, University of Tasmania, Hobart TAS, Australia
| | | | - Miguel Jarrin
- Department of Biosciences, South Road, Durham University, Durham, DH1 3LE, England, UK
| | - Roy A Quinlan
- Department of Biosciences, South Road, Durham University, Durham, DH1 3LE, England, UK.
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Nanda SK, Prescott AR, Figueras-Vadillo C, Cohen P. IKKβ is required for the formation of the NLRP3 inflammasome. EMBO Rep 2021; 22:e50743. [PMID: 34403206 PMCID: PMC8490994 DOI: 10.15252/embr.202050743] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 07/26/2021] [Accepted: 07/30/2021] [Indexed: 11/29/2022] Open
Abstract
The rapid formation and activation of the NLRP3 inflammasome is induced by co‐stimulation with LPS and nigericin. It requires the LPS‐stimulated activation of IKKβ, which exerts its effects independently of de novo gene transcription, protein translation and other protein kinases activated by IKKβ. IKKβ is not required for the nigericin‐induced dispersion of the trans‐Golgi network (TGN), but to bring NLRP3 in proximity with TGN38. The nigericin‐induced dispersion of the Golgi is enhanced by co‐stimulation with LPS, and this enhancement is IKKβ‐dependent. Prolonged stimulation with LPS to increase the expression of NLRP3, followed by stimulation with nigericin, produced larger TGN38‐positive puncta, and the ensuing activation of the NLRP3 inflammasome was also suppressed by IKKβ inhibitors added prior to stimulation with nigericin. IKKβ therefore has a key role in recruiting NLRP3 to the dispersed TGN, leading to the formation and activation of the NLRP3 inflammasome.
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Affiliation(s)
- Sambit K Nanda
- MRC Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Dundee, UK
| | - Alan R Prescott
- Dundee Imaging Facility and Division of Cell Signalling and Immunology, School of Life Sciences, University of Dundee, Dundee, UK
| | | | - Philip Cohen
- MRC Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Dundee, UK
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Singh F, Prescott AR, Rosewell P, Ball G, Reith AD, Ganley IG. Pharmacological rescue of impaired mitophagy in Parkinson's disease-related LRRK2 G2019S knock-in mice. eLife 2021; 10:e67604. [PMID: 34340748 PMCID: PMC8331189 DOI: 10.7554/elife.67604] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 06/30/2021] [Indexed: 01/01/2023] Open
Abstract
Parkinson's disease (PD) is a major and progressive neurodegenerative disorder, yet the biological mechanisms involved in its aetiology are poorly understood. Evidence links this disorder with mitochondrial dysfunction and/or impaired lysosomal degradation - key features of the autophagy of mitochondria, known as mitophagy. Here, we investigated the role of LRRK2, a protein kinase frequently mutated in PD, in this process in vivo. Using mitophagy and autophagy reporter mice, bearing either knockout of LRRK2 or expressing the pathogenic kinase-activating G2019S LRRK2 mutation, we found that basal mitophagy was specifically altered in clinically relevant cells and tissues. Our data show that basal mitophagy inversely correlates with LRRK2 kinase activity in vivo. In support of this, use of distinct LRRK2 kinase inhibitors in cells increased basal mitophagy, and a CNS penetrant LRRK2 kinase inhibitor, GSK3357679A, rescued the mitophagy defects observed in LRRK2 G2019S mice. This study provides the first in vivo evidence that pathogenic LRRK2 directly impairs basal mitophagy, a process with strong links to idiopathic Parkinson's disease, and demonstrates that pharmacological inhibition of LRRK2 is a rational mitophagy-rescue approach and potential PD therapy.
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Affiliation(s)
- Francois Singh
- MRC Protein Phosphorylation and Ubiquitylation Unit, University of DundeeDundeeUnited Kingdom
| | - Alan R Prescott
- Dundee Imaging Facility, School of Life Sciences, University of DundeeDundeeUnited Kingdom
| | - Philippa Rosewell
- MRC Protein Phosphorylation and Ubiquitylation Unit, University of DundeeDundeeUnited Kingdom
| | - Graeme Ball
- Dundee Imaging Facility, School of Life Sciences, University of DundeeDundeeUnited Kingdom
| | - Alastair D Reith
- Novel Human Genetics Research Unit, GlaxoSmithKline Pharmaceuticals R&DStevenageUnited Kingdom
| | - Ian G Ganley
- MRC Protein Phosphorylation and Ubiquitylation Unit, University of DundeeDundeeUnited Kingdom
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Sampaio Guther ML, Prescott AR, Kuettel S, Tinti M, Ferguson MAJ. Nucleotide sugar biosynthesis occurs in the glycosomes of procyclic and bloodstream form Trypanosoma brucei. PLoS Negl Trop Dis 2021; 15:e0009132. [PMID: 33592041 PMCID: PMC7909634 DOI: 10.1371/journal.pntd.0009132] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 02/26/2021] [Accepted: 01/12/2021] [Indexed: 11/19/2022] Open
Abstract
In Trypanosoma brucei, there are fourteen enzymatic biotransformations that collectively convert glucose into five essential nucleotide sugars: UDP-Glc, UDP-Gal, UDP-GlcNAc, GDP-Man and GDP-Fuc. These biotransformations are catalyzed by thirteen discrete enzymes, five of which possess putative peroxisome targeting sequences. Published experimental analyses using immunofluorescence microscopy and/or digitonin latency and/or subcellular fractionation and/or organelle proteomics have localized eight and six of these enzymes to the glycosomes of bloodstream form and procyclic form T. brucei, respectively. Here we increase these glycosome localizations to eleven in both lifecycle stages while noting that one, phospho-N-acetylglucosamine mutase, also localizes to the cytoplasm. In the course of these studies, the heterogeneity of glycosome contents was also noted. These data suggest that, unlike other eukaryotes, all of nucleotide sugar biosynthesis in T. brucei is compartmentalized to the glycosomes in both lifecycle stages. The implications are discussed.
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Affiliation(s)
- Maria Lucia Sampaio Guther
- Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Alan R. Prescott
- Dundee Imaging Facility, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Sabine Kuettel
- Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Michele Tinti
- Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Michael A. J. Ferguson
- Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, United Kingdom
- * E-mail:
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11
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Obst J, Simon E, Martin-Estebane M, Pipi E, Barkwill LM, Gonzalez-Rivera I, Buchanan F, Prescott AR, Faust D, Fox S, Brownlees J, Taylor D, Perry VH, Nuthall H, Atkinson PJ, Karran E, Routledge C, Gomez-Nicola D. Inhibition of IL-34 Unveils Tissue-Selectivity and Is Sufficient to Reduce Microglial Proliferation in a Model of Chronic Neurodegeneration. Front Immunol 2020; 11:579000. [PMID: 33162994 PMCID: PMC7580706 DOI: 10.3389/fimmu.2020.579000] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 08/27/2020] [Indexed: 01/15/2023] Open
Abstract
The proliferation and activation of microglia, the resident macrophages in the brain, is a hallmark of many neurodegenerative diseases such as Alzheimer's disease (AD) and prion disease. Colony stimulating factor 1 receptor (CSF1R) is critically involved in regulating microglial proliferation, and CSF1R blocking strategies have been recently used to modulate microglia in neurodegenerative diseases. However, CSF1R is broadly expressed by many cell types and the impact of its inhibition on the innate immune system is still unclear. CSF1R can be activated by two independent ligands, CSF-1 and interleukin 34 (IL-34). Recently, it has been reported that microglia development and maintenance depend on IL-34 signaling. In this study, we evaluate the inhibition of IL-34 as a novel strategy to reduce microglial proliferation in the ME7 model of prion disease. Selective inhibition of IL-34 showed no effects on peripheral macrophage populations in healthy mice, avoiding the side effects observed after CSF1R inhibition on the systemic compartment. However, we observed a reduction in microglial proliferation after IL-34 inhibition in prion-diseased mice, indicating that microglia could be more specifically targeted by reducing IL-34. Overall, our results highlight the challenges of targeting the CSF1R/IL34 axis in the systemic and central compartments, important for framing any therapeutic effort to tackle microglia/macrophage numbers during brain disease.
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MESH Headings
- Animals
- Antibodies, Monoclonal/pharmacology
- Antibodies, Monoclonal/toxicity
- Antibodies, Neutralizing/pharmacology
- Antibodies, Neutralizing/toxicity
- Brain/drug effects
- Brain/metabolism
- Brain/pathology
- Cell Line, Tumor
- Cell Proliferation/drug effects
- Disease Models, Animal
- Genes, fms
- Green Fluorescent Proteins/genetics
- Green Fluorescent Proteins/metabolism
- Interleukins/antagonists & inhibitors
- Interleukins/metabolism
- Mice, Inbred C57BL
- Mice, Transgenic
- Microglia/drug effects
- Microglia/metabolism
- Microglia/pathology
- Nerve Degeneration
- Prion Diseases/drug therapy
- Prion Diseases/metabolism
- Prion Diseases/pathology
- Receptors, Granulocyte-Macrophage Colony-Stimulating Factor/antagonists & inhibitors
- Receptors, Granulocyte-Macrophage Colony-Stimulating Factor/metabolism
- Signal Transduction
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Affiliation(s)
- Juliane Obst
- School of Biological Sciences, Southampton General Hospital, University of Southampton, Southampton, United Kingdom
| | - Emilie Simon
- School of Biological Sciences, Southampton General Hospital, University of Southampton, Southampton, United Kingdom
| | - Maria Martin-Estebane
- School of Biological Sciences, Southampton General Hospital, University of Southampton, Southampton, United Kingdom
| | - Elena Pipi
- School of Biological Sciences, Southampton General Hospital, University of Southampton, Southampton, United Kingdom
| | - Liana M. Barkwill
- School of Biological Sciences, Southampton General Hospital, University of Southampton, Southampton, United Kingdom
| | - Ivette Gonzalez-Rivera
- School of Biological Sciences, Southampton General Hospital, University of Southampton, Southampton, United Kingdom
| | - Fergus Buchanan
- Dundee Imaging Facility, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Alan R. Prescott
- Dundee Imaging Facility, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Dorte Faust
- Centre for Therapeutics Discovery, LifeArc, Accelerator Building, Stevenage, United Kingdom
| | - Simon Fox
- Centre for Therapeutics Discovery, LifeArc, Accelerator Building, Stevenage, United Kingdom
| | - Janet Brownlees
- Centre for Therapeutics Discovery, LifeArc, Accelerator Building, Stevenage, United Kingdom
| | - Debra Taylor
- Centre for Therapeutics Discovery, LifeArc, Accelerator Building, Stevenage, United Kingdom
| | - V. Hugh Perry
- School of Biological Sciences, Southampton General Hospital, University of Southampton, Southampton, United Kingdom
| | - Hugh Nuthall
- Eli Lilly Research Centre, Surrey, United Kingdom
| | - Peter J. Atkinson
- Eisai Limited, European Knowledge Centre, Hertfordshire, United Kingdom
| | - Eric Karran
- Abbvie, Foundational Neuroscience Centre, Cambridge, MA, United States
| | | | - Diego Gomez-Nicola
- School of Biological Sciences, Southampton General Hospital, University of Southampton, Southampton, United Kingdom
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12
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Ibrahim AFM, Shen L, Tatham MH, Dickerson D, Prescott AR, Abidi N, Xirodimas DP, Hay RT. Antibody RING-Mediated Destruction of Endogenous Proteins. Mol Cell 2020; 79:155-166.e9. [PMID: 32454028 PMCID: PMC7332993 DOI: 10.1016/j.molcel.2020.04.032] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 03/20/2020] [Accepted: 04/27/2020] [Indexed: 01/05/2023]
Abstract
To understand gene function, the encoding DNA or mRNA transcript can be manipulated and the consequences observed. However, these approaches do not have a direct effect on the protein product of the gene, which is either permanently abrogated or depleted at a rate defined by the half-life of the protein. We therefore developed a single-component system that could induce the rapid degradation of the specific endogenous protein itself. A construct combining the RING domain of ubiquitin E3 ligase RNF4 with a protein-specific camelid nanobody mediates target destruction by the ubiquitin proteasome system, a process we describe as antibody RING-mediated destruction (ARMeD). The technique is highly specific because we observed no off-target protein destruction. Furthermore, bacterially produced nanobody-RING fusion proteins electroporated into cells induce degradation of target within minutes. With increasing availability of protein-specific nanobodies, this method will allow rapid and specific degradation of a wide range of endogenous proteins.
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Affiliation(s)
- Adel F M Ibrahim
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Linnan Shen
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Michael H Tatham
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - David Dickerson
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Alan R Prescott
- Dundee Imaging Facility, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Naima Abidi
- Cell Biology Research Centre of Montpellier, CNRS, UMR 5237, Montpellier, France
| | - Dimitris P Xirodimas
- Cell Biology Research Centre of Montpellier, CNRS, UMR 5237, Montpellier, France
| | - Ronald T Hay
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK.
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13
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Bozic M, van den Bekerom L, Milne BA, Goodman N, Roberston L, Prescott AR, Macartney TJ, Dawe N, McEwan DG. A conserved ATG2-GABARAP family interaction is critical for phagophore formation. EMBO Rep 2020; 21:e48412. [PMID: 32009292 PMCID: PMC7054675 DOI: 10.15252/embr.201948412] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 12/16/2019] [Accepted: 12/23/2019] [Indexed: 01/08/2023] Open
Abstract
The intracellular trafficking pathway, macroautophagy, is a recycling and disposal service that can be upregulated during periods of stress to maintain cellular homeostasis. An essential phase is the elongation and closure of the phagophore to seal and isolate unwanted cargo prior to lysosomal degradation. Human ATG2A and ATG2B proteins, through their interaction with WIPI proteins, are thought to be key players during phagophore elongation and closure, but little mechanistic detail is known about their function. We have identified a highly conserved motif driving the interaction between human ATG2 and GABARAP proteins that is in close proximity to the ATG2‐WIPI4 interaction site. We show that the ATG2A‐GABARAP interaction mutants are unable to form and close phagophores resulting in blocked autophagy, similar to ATG2A/ATG2B double‐knockout cells. In contrast, the ATG2A‐WIPI4 interaction mutant fully restored phagophore formation and autophagy flux, similar to wild‐type ATG2A. Taken together, we provide new mechanistic insights into the requirements for ATG2 function at the phagophore and suggest that an ATG2‐GABARAP/GABARAP‐L1 interaction is essential for phagophore formation, whereas ATG2‐WIPI4 interaction is dispensable.
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Affiliation(s)
- Mihaela Bozic
- Division of Cell Signalling & Immunology, School of Life Sciences, University of Dundee, Dundee, UK.,Edinburgh Cancer Research UK Centre, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - Luuk van den Bekerom
- Division of Cell Signalling & Immunology, School of Life Sciences, University of Dundee, Dundee, UK.,MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, UK
| | - Beth A Milne
- Division of Cell Signalling & Immunology, School of Life Sciences, University of Dundee, Dundee, UK
| | - Nicola Goodman
- Division of Cell Signalling & Immunology, School of Life Sciences, University of Dundee, Dundee, UK.,MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, UK
| | - Lisa Roberston
- Division of Cell Signalling & Immunology, School of Life Sciences, University of Dundee, Dundee, UK
| | - Alan R Prescott
- Dundee Imaging Facility, School of Life Sciences, University of Dundee, Dundee, UK
| | - Thomas J Macartney
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, UK
| | - Nina Dawe
- Division of Cell Signalling & Immunology, School of Life Sciences, University of Dundee, Dundee, UK
| | - David G McEwan
- Division of Cell Signalling & Immunology, School of Life Sciences, University of Dundee, Dundee, UK.,Cancer Research UK Beatson Institute, Glasgow, UK
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14
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Elias MS, Wright SC, Nicholson WV, Morrison KD, Prescott AR, Ten Have S, Whitfield PD, Lamond AI, Brown SJ. Functional and proteomic analysis of a full thickness filaggrin-deficient skin organoid model. Wellcome Open Res 2019; 4:134. [PMID: 31641698 PMCID: PMC6790913 DOI: 10.12688/wellcomeopenres.15405.2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/21/2019] [Indexed: 12/16/2022] Open
Abstract
Background: Atopic eczema is an itchy inflammatory disorder characterised by skin barrier dysfunction. Loss-of-function mutations in the gene encoding filaggrin (
FLG) are a major risk factor, but the mechanisms by which filaggrin haploinsufficiency leads to atopic inflammation remain incompletely understood. Skin as an organ that can be modelled using primary cells
in vitro provides the opportunity for selected genetic effects to be investigated in detail. Methods: Primary human keratinocytes and donor-matched primary fibroblasts from healthy individuals were used to create skin organoid models with and without siRNA-mediated knockdown of
FLG. Biological replicate sets of organoids were assessed using histological, functional and biochemical measurements. Results:FLG knockdown leads to subtle changes in histology and ultrastructure including a reduction in thickness of the stratum corneum and smaller, less numerous keratohyalin granules. Immature organoids showed some limited evidence of barrier impairment with
FLG knockdown, but the mature organoids showed no difference in transepidermal water loss, water content or dye penetration. There was no difference in epidermal ceramide content. Mass spectrometry proteomic analysis detected >8000 proteins per sample. Gene ontology and pathway analyses identified an increase in transcriptional and translational activity but a reduction in proteins contributing to terminal differentiation, including caspase 14, dermokine, AKT1 and TGF-beta-1. Aspects of innate and adaptive immunity were represented in both the up-regulated and down-regulated protein groups, as was the term ‘axon guidance’. Conclusions: This work provides further evidence for keratinocyte-specific mechanisms contributing to immune and neurological, as well as structural, aspects of skin barrier dysfunction. Individuals with filaggrin deficiency may derive benefit from future therapies targeting keratinocyte-immune crosstalk and neurogenic pruritus.
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Affiliation(s)
- Martina S Elias
- Skin Research Group, Division of Molecular and Clinical Medicine, School of Medicine, University of Dundee, Dundee, Scotland, DD1 9SY, UK
| | - Sheila C Wright
- Skin Research Group, Division of Molecular and Clinical Medicine, School of Medicine, University of Dundee, Dundee, Scotland, DD1 9SY, UK
| | - William V Nicholson
- Skin Research Group, Division of Molecular and Clinical Medicine, School of Medicine, University of Dundee, Dundee, Scotland, DD1 9SY, UK
| | - Kimberley D Morrison
- Skin Research Group, Division of Molecular and Clinical Medicine, School of Medicine, University of Dundee, Dundee, Scotland, DD1 9SY, UK
| | - Alan R Prescott
- Dundee Imaging Facility, School of Life Sciences, University of Dundee, Dundee, Scotland, DD1 5EH, UK
| | - Sara Ten Have
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, Scotland, DD1 5EH, UK
| | - Phillip D Whitfield
- Lipidomics Research Facility, Division of Biomedical Sciences, University of the Highlands and Islands, Inverness, Scotland, IV2 3JH, UK
| | - Angus I Lamond
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, Scotland, DD1 5EH, UK
| | - Sara J Brown
- Skin Research Group, Division of Molecular and Clinical Medicine, School of Medicine, University of Dundee, Dundee, Scotland, DD1 9SY, UK.,Department of Dermatology, Ninewells Hospital, Dundee, Scotland, DD1 9SY, UK
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15
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Elias MS, Wright SC, Nicholson WV, Morrison KD, Prescott AR, Ten Have S, Whitfield PD, Lamond AI, Brown SJ. Proteomic analysis of a filaggrin-deficient skin organoid model shows evidence of increased transcriptional-translational activity, keratinocyte-immune crosstalk and disordered axon guidance. Wellcome Open Res 2019; 4:134. [DOI: 10.12688/wellcomeopenres.15405.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/30/2019] [Indexed: 11/20/2022] Open
Abstract
Background:Atopic eczema is an itchy inflammatory disorder characterised by skin barrier dysfunction. Loss-of-function mutations in the gene encoding filaggrin (FLG) are a major risk factor, but the mechanisms by which filaggrin haploinsufficiency leads to atopic inflammation remain incompletely understood. Skin as an organ that can be modelled using primary cellsin vitroprovides the opportunity for selected genetic effects to be investigated in detail.Methods:Primary human keratinocytes and donor-matched primary fibroblasts from healthy individuals were used to create skin organoid models with and without siRNA-mediated knockdown ofFLG. Biological replicate sets of organoids were assessed using histological, functional and biochemical measurements.Results:FLGknockdown leads to subtle changes in histology and ultrastructure including a reduction in thickness of the stratum corneum and smaller, less numerous keratohyalin granules. Immature organoids showed evidence of barrier impairment withFLGknockdown, but the mature organoids showed no difference in transepidermal water loss, water content or dye penetration. There was no difference in epidermal ceramide content. Mass spectrometry proteomic analysis detected >8000 proteins per sample. Gene ontology and pathway analyses identified an increase in transcriptional and translational activity but a reduction in proteins contributing to terminal differentiation, including caspase 14, dermokine, AKT1 and TGF-beta-1. Aspects of innate and adaptive immunity were represented in both the up-regulated and down-regulated protein groups, as was the term ‘axon guidance’. Conclusions:This work provides further evidence for keratinocyte-specific mechanisms contributing to immune and neurological, as well as structural, aspects of skin barrier dysfunction. Individuals with filaggrin deficiency may derive benefit from future therapies targeting keratinocyte-immune crosstalk and neurogenic pruritus.
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16
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Fulcher LJ, He Z, Mei L, Macartney TJ, Wood NT, Prescott AR, Whigham AJ, Varghese J, Gourlay R, Ball G, Clarke R, Campbell DG, Maxwell CA, Sapkota GP. FAM83D directs protein kinase CK1α to the mitotic spindle for proper spindle positioning. EMBO Rep 2019; 20:e47495. [PMID: 31338967 PMCID: PMC6726907 DOI: 10.15252/embr.201847495] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 06/13/2019] [Accepted: 06/26/2019] [Indexed: 12/26/2022] Open
Abstract
The concerted action of many protein kinases helps orchestrate the error-free progression through mitosis of mammalian cells. The roles and regulation of some prominent mitotic kinases, such as cyclin-dependent kinases, are well established. However, these and other known mitotic kinases alone cannot account for the extent of protein phosphorylation that has been reported during mammalian mitosis. Here we demonstrate that CK1α, of the casein kinase 1 family of protein kinases, localises to the spindle and is required for proper spindle positioning and timely cell division. CK1α is recruited to the spindle by FAM83D, and cells devoid of FAM83D, or those harbouring CK1α-binding-deficient FAM83DF283A/F283A knockin mutations, display pronounced spindle positioning defects, and a prolonged mitosis. Restoring FAM83D at the endogenous locus in FAM83D-/- cells, or artificially delivering CK1α to the spindle in FAM83DF283A/F283A cells, rescues these defects. These findings implicate CK1α as new mitotic kinase that orchestrates the kinetics and orientation of cell division.
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Affiliation(s)
- Luke J Fulcher
- Medical Research Council, Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Dundee, UK
| | - Zhengcheng He
- Michael Cuccione Childhood Cancer Research Program, British Columbia Children's Hospital, University of British Columbia, Vancouver, BC, Canada
| | - Lin Mei
- Michael Cuccione Childhood Cancer Research Program, British Columbia Children's Hospital, University of British Columbia, Vancouver, BC, Canada
| | - Thomas J Macartney
- Medical Research Council, Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Dundee, UK
| | - Nicola T Wood
- Medical Research Council, Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Dundee, UK
| | - Alan R Prescott
- Dundee Imaging Facility, School of Life Sciences, University of Dundee, Dundee, UK
| | - Arlene J Whigham
- Flow Cytometry and Sorting Facility, School of Life Sciences, University of Dundee, Dundee, UK
| | - Joby Varghese
- Medical Research Council, Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Dundee, UK
| | - Robert Gourlay
- Medical Research Council, Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Dundee, UK
| | - Graeme Ball
- Dundee Imaging Facility, School of Life Sciences, University of Dundee, Dundee, UK
| | - Rosemary Clarke
- Flow Cytometry and Sorting Facility, School of Life Sciences, University of Dundee, Dundee, UK
| | - David G Campbell
- Medical Research Council, Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Dundee, UK
| | - Christopher A Maxwell
- Michael Cuccione Childhood Cancer Research Program, British Columbia Children's Hospital, University of British Columbia, Vancouver, BC, Canada
| | - Gopal P Sapkota
- Medical Research Council, Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Dundee, UK
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17
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McWilliams TG, Prescott AR, Villarejo-Zori B, Ball G, Boya P, Ganley IG. A comparative map of macroautophagy and mitophagy in the vertebrate eye. Autophagy 2019; 15:1296-1308. [PMID: 30786807 PMCID: PMC6613837 DOI: 10.1080/15548627.2019.1580509] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 01/11/2019] [Accepted: 01/29/2019] [Indexed: 02/08/2023] Open
Abstract
Photoreception is pivotal to our experience and perception of the natural world; hence the eye is of prime importance for most vertebrate animals to sense light. Central to visual health is mitochondrial homeostasis, and the selective autophagic turnover of mitochondria (mitophagy) is predicted to play a key role here. Despite studies that link aberrant mitophagy to ocular dysfunction, little is known about the prevalence of basal mitophagy, or its relationship to general autophagy, in the visual system. In this study, we utilize the mito-QC mouse and a closely related general macroautophagy reporter model to profile basal mitophagy and macroautophagy in the adult and developing eye. We report that ocular macroautophagy is widespread, but surprisingly mitophagy does not always follow the same pattern of occurrence. We observe low levels of mitophagy in the lens and ciliary body, in stark contrast to the high levels of general MAP1LC3-dependent macroautophagy in these regions. We uncover a striking reversal of this process in the adult retina, where mitophagy accounts for a larger degree of the macroautophagy taking place, specifically in the photoreceptor neurons of the outer nuclear layer. We also show the developmental regulation of autophagy in a variety of ocular tissues. In particular, mitophagy in the adult mouse retina is reversed in localization during the latter stages of development. Our work thus defines the landscape of mitochondrial homeostasis in the mammalian eye, and in doing so highlights the selective nature of autophagy in vivo and the specificity of the reporters used. Abbreviations: ATG: autophagy related; GFP: green fluorescent protein; LC3: microtubule associated protein 1 light chain 3; ONH: optic nerve head; ONL: outer nuclear layer; RPE: retinal pigment epithelium.
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Affiliation(s)
- Thomas G. McWilliams
- MRC Protein Phosphorylation and Ubiquitylation Unit, Sir James Black Centre School of Life Sciences, University of Dundee, Dundee, UK
- Translational Stem Cell Biology & Metabolism Program, Research Programs Unit, Faculty of Medicine, University of Helsinki, Finland
| | - Alan R. Prescott
- Dundee Imaging Facility, School of Life Sciences, University of Dundee, Dundee, UK
| | - Beatriz Villarejo-Zori
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas, CSIC, Madrid, Spain
| | - Graeme Ball
- Dundee Imaging Facility, School of Life Sciences, University of Dundee, Dundee, UK
| | - Patricia Boya
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas, CSIC, Madrid, Spain
| | - Ian G. Ganley
- MRC Protein Phosphorylation and Ubiquitylation Unit, Sir James Black Centre School of Life Sciences, University of Dundee, Dundee, UK
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18
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Elias MS, Wright SC, Remenyi J, Abbott JC, Bray SE, Cole C, Edwards S, Gierlinski M, Glok M, McGrath JA, Nicholson WV, Paternoster L, Prescott AR, Have ST, Whitfield PD, Lamond AI, Brown SJ. EMSY expression affects multiple components of the skin barrier with relevance to atopic dermatitis. J Allergy Clin Immunol 2019; 144:470-481. [PMID: 31158401 PMCID: PMC6683598 DOI: 10.1016/j.jaci.2019.05.024] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 05/07/2019] [Accepted: 05/14/2019] [Indexed: 12/14/2022]
Abstract
Background Atopic dermatitis (AD) is a common, complex, and highly heritable inflammatory skin disease. Genome-wide association studies offer opportunities to identify molecular targets for drug development. A risk locus on chromosome 11q13.5 lies between 2 candidate genes, EMSY and LRRC32 (leucine-rich repeat-containing 32) but the functional mechanisms affecting risk of AD remain unclear. Objectives We sought to apply a combination of genomic and molecular analytic techniques to investigate which genes are responsible for genetic risk at this locus and to define mechanisms contributing to atopic skin disease. Methods We used interrogation of available genomic and chromosome conformation data in keratinocytes, small interfering RNA (siRNA)–mediated knockdown in skin organotypic culture and functional assessment of barrier parameters, mass spectrometric global proteomic analysis and quantitative lipid analysis, electron microscopy of organotypic skin, and immunohistochemistry of human skin samples. Results Genomic data indicate active promoters in the genome-wide association study locus and upstream of EMSY; EMSY, LRRC32, and intergenic variants all appear to be within a single topologically associating domain. siRNA-knockdown of EMSY in organotypic culture leads to enhanced development of barrier function, reflecting increased expression of structural and functional proteins, including filaggrin and filaggrin-2, as well as long-chain ceramides. Conversely, overexpression of EMSY in keratinocytes leads to a reduction in markers of barrier formation. Skin biopsy samples from patients with AD show greater EMSY staining in the nucleus, which is consistent with an increased functional effect of this transcriptional control protein. Conclusion Our findings demonstrate an important role for EMSY in transcriptional regulation and skin barrier formation, supporting EMSY inhibition as a therapeutic approach.
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Affiliation(s)
- Martina S Elias
- Skin Research Group, Division of Molecular and Clinical Medicine, School of Medicine, University of Dundee, Dundee, United Kingdom.
| | - Sheila C Wright
- Skin Research Group, Division of Molecular and Clinical Medicine, School of Medicine, University of Dundee, Dundee, United Kingdom
| | - Judit Remenyi
- Skin Research Group, Division of Molecular and Clinical Medicine, School of Medicine, University of Dundee, Dundee, United Kingdom
| | - James C Abbott
- Data Analysis/Bioinformatics Group, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Susan E Bray
- NHS Research Scotland Biorepository Tayside, Ninewells Hospital and Medical School, University of Dundee, Dundee, United Kingdom
| | - Christian Cole
- Data Analysis/Bioinformatics Group, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Sharon Edwards
- Department of Pathology, Ninewells Hospital and Medical School, Dundee, United Kingdom
| | - Marek Gierlinski
- Data Analysis/Bioinformatics Group, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Mateusz Glok
- Skin Research Group, Division of Molecular and Clinical Medicine, School of Medicine, University of Dundee, Dundee, United Kingdom
| | - John A McGrath
- St John's Institute of Dermatology, King's College London (Guy's Campus), London, United Kingdom
| | - William V Nicholson
- Skin Research Group, Division of Molecular and Clinical Medicine, School of Medicine, University of Dundee, Dundee, United Kingdom
| | - Lavinia Paternoster
- MRC Integrative Epidemiology Unit, Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Alan R Prescott
- Dundee Imaging Facility, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Sara Ten Have
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Phillip D Whitfield
- Lipidomics Research Facility, Division of Biomedical Sciences, University of the Highlands and Islands, Inverness, United Kingdom
| | - Angus I Lamond
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Sara J Brown
- Skin Research Group, Division of Molecular and Clinical Medicine, School of Medicine, University of Dundee, Dundee, United Kingdom; Department of Dermatology, Ninewells Hospital, Dundee, United Kingdom.
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19
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Tovell H, Testa A, Maniaci C, Zhou H, Prescott AR, Macartney T, Ciulli A, Alessi DR. Rapid and Reversible Knockdown of Endogenously Tagged Endosomal Proteins via an Optimized HaloPROTAC Degrader. ACS Chem Biol 2019; 14:882-892. [PMID: 30978004 PMCID: PMC6528276 DOI: 10.1021/acschembio.8b01016] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
![]()
Inducing
post-translational protein knockdown is an important approach
to probe biology and validate drug targets. An efficient strategy
to achieve this involves expression of a protein of interest fused
to an exogenous tag, allowing tag-directed chemical degraders to mediate
protein ubiquitylation and proteasomal degradation. Here, we combine
improved HaloPROTAC degrader probes with CRISPR/Cas9 genome editing
technology to trigger rapid degradation of endogenous target proteins.
Our optimized probe, HaloPROTAC-E, a chloroalkane conjugate of high-affinity
VHL binder VH298, induced reversible degradation of two endosomally
localized proteins, SGK3 and VPS34, with a DC50 of 3–10
nM. HaloPROTAC-E induced rapid (∼50% degradation after 30 min)
and complete (Dmax of ∼95% at 48
h) depletion of Halo-tagged SGK3, blocking downstream phosphorylation
of the SGK3 substrate NDRG1. HaloPROTAC-E more potently induced greater
steady state degradation of Halo tagged endogenous VPS34 than the
previously reported HaloPROTAC3 compound. Quantitative global proteomics
revealed that HaloPROTAC-E is remarkably selective inducing only degradation
of the Halo tagged endogenous VPS34 complex (VPS34, VPS15, Beclin1,
and ATG14) and no other proteins were significantly degraded. This
study exemplifies the combination of HaloPROTACs with CRISPR/Cas9
endogenous protein tagging as a useful method to induce rapid and
reversible degradation of endogenous proteins to interrogate their
function.
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Affiliation(s)
- Hannah Tovell
- Medical Research Council (MRC) Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, U.K
| | - Andrea Testa
- Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Dow Street, Dundee, DD1 5EH, U.K
| | - Chiara Maniaci
- Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Dow Street, Dundee, DD1 5EH, U.K
| | - Houjiang Zhou
- Medical Research Council (MRC) Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, U.K
| | - Alan R Prescott
- Dundee Imaging Facility, School of Life Sciences, University of Dundee, Dundee DD1 5EH, U.K
| | - Thomas Macartney
- Medical Research Council (MRC) Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, U.K
| | - Alessio Ciulli
- Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Dow Street, Dundee, DD1 5EH, U.K
| | - Dario R Alessi
- Medical Research Council (MRC) Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, U.K
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20
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McWilliams TG, Barini E, Pohjolan-Pirhonen R, Brooks SP, Singh F, Burel S, Balk K, Kumar A, Montava-Garriga L, Prescott AR, Hassoun SM, Mouton-Liger F, Ball G, Hills R, Knebel A, Ulusoy A, Di Monte DA, Tamjar J, Antico O, Fears K, Smith L, Brambilla R, Palin E, Valori M, Eerola-Rautio J, Tienari P, Corti O, Dunnett SB, Ganley IG, Suomalainen A, Muqit MMK. Phosphorylation of Parkin at serine 65 is essential for its activation in vivo. Open Biol 2018; 8:rsob.180108. [PMID: 30404819 PMCID: PMC6282074 DOI: 10.1098/rsob.180108] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Mutations in PINK1 and Parkin result in autosomal recessive Parkinson's disease (PD). Cell culture and in vitro studies have elaborated the PINK1-dependent regulation of Parkin and defined how this dyad orchestrates the elimination of damaged mitochondria via mitophagy. PINK1 phosphorylates ubiquitin at serine 65 (Ser65) and Parkin at an equivalent Ser65 residue located within its N-terminal ubiquitin-like domain, resulting in activation; however, the physiological significance of Parkin Ser65 phosphorylation in vivo in mammals remains unknown. To address this, we generated a Parkin Ser65Ala (S65A) knock-in mouse model. We observe endogenous Parkin Ser65 phosphorylation and activation in mature primary neurons following mitochondrial depolarization and reveal this is disrupted in Parkin S65A/S65A neurons. Phenotypically, Parkin S65A/S65A mice exhibit selective motor dysfunction in the absence of any overt neurodegeneration or alterations in nigrostriatal mitophagy. The clinical relevance of our findings is substantiated by the discovery of homozygous PARKIN (PARK2) p.S65N mutations in two unrelated patients with PD. Moreover, biochemical and structural analysis demonstrates that the ParkinS65N/S65N mutant is pathogenic and cannot be activated by PINK1. Our findings highlight the central role of Parkin Ser65 phosphorylation in health and disease.
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Affiliation(s)
- Thomas G McWilliams
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK .,Research Programs Unit, Molecular Neurology, University of Helsinki, 00290 Helsinki, Finland
| | - Erica Barini
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Risto Pohjolan-Pirhonen
- Research Programs Unit, Molecular Neurology, University of Helsinki, 00290 Helsinki, Finland.,Neuroscience Center, University of Helsinki, 00290 Helsinki, Finland.,Helsinki University Hospital, 00290 Helsinki, Finland
| | - Simon P Brooks
- The Brain Repair Group, Division of Neuroscience, School of Biosciences, Cardiff University, Wales CF10 3AX, UK
| | - François Singh
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Sophie Burel
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Kristin Balk
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Atul Kumar
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Lambert Montava-Garriga
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Alan R Prescott
- Dundee Imaging Facility, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | | | | | - Graeme Ball
- Dundee Imaging Facility, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Rachel Hills
- The Brain Repair Group, Division of Neuroscience, School of Biosciences, Cardiff University, Wales CF10 3AX, UK
| | - Axel Knebel
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Ayse Ulusoy
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | | | - Jevgenia Tamjar
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Odetta Antico
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Kyle Fears
- The Brain Repair Group, Division of Neuroscience, School of Biosciences, Cardiff University, Wales CF10 3AX, UK
| | - Laura Smith
- The Brain Repair Group, Division of Neuroscience, School of Biosciences, Cardiff University, Wales CF10 3AX, UK
| | - Riccardo Brambilla
- Neuroscience & Mental Health Institute, Neuroscience Division, School of Biosciences, Hadyn Ellis Building, Maindy Road, Cardiff CF24 4HQ, UK
| | - Eino Palin
- Research Programs Unit, Molecular Neurology, University of Helsinki, 00290 Helsinki, Finland.,Neuroscience Center, University of Helsinki, 00290 Helsinki, Finland.,Helsinki University Hospital, 00290 Helsinki, Finland
| | - Miko Valori
- Research Programs Unit, Molecular Neurology, University of Helsinki, 00290 Helsinki, Finland.,Neuroscience Center, University of Helsinki, 00290 Helsinki, Finland.,Helsinki University Hospital, 00290 Helsinki, Finland
| | - Johanna Eerola-Rautio
- Research Programs Unit, Molecular Neurology, University of Helsinki, 00290 Helsinki, Finland.,Neuroscience Center, University of Helsinki, 00290 Helsinki, Finland.,Helsinki University Hospital, 00290 Helsinki, Finland.,Department of Neurology, Helsinki University Hospital, Haartmaninkatu 4, Helsinki, FI 00290, Finland
| | - Pentti Tienari
- Research Programs Unit, Molecular Neurology, University of Helsinki, 00290 Helsinki, Finland.,Neuroscience Center, University of Helsinki, 00290 Helsinki, Finland.,Helsinki University Hospital, 00290 Helsinki, Finland
| | | | - Stephen B Dunnett
- The Brain Repair Group, Division of Neuroscience, School of Biosciences, Cardiff University, Wales CF10 3AX, UK
| | - Ian G Ganley
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Anu Suomalainen
- Research Programs Unit, Molecular Neurology, University of Helsinki, 00290 Helsinki, Finland.,Neuroscience Center, University of Helsinki, 00290 Helsinki, Finland.,Helsinki University Hospital, 00290 Helsinki, Finland
| | - Miratul M K Muqit
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK .,School of Medicine, University of Dundee, Dundee DD1 9SY, UK
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21
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McWilliams TG, Prescott AR, Montava-Garriga L, Ball G, Singh F, Barini E, Muqit MMK, Brooks SP, Ganley IG. Basal Mitophagy Occurs Independently of PINK1 in Mouse Tissues of High Metabolic Demand. Cell Metab 2018; 27:439-449.e5. [PMID: 29337137 PMCID: PMC5807059 DOI: 10.1016/j.cmet.2017.12.008] [Citation(s) in RCA: 379] [Impact Index Per Article: 63.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2017] [Revised: 10/13/2017] [Accepted: 12/12/2017] [Indexed: 02/08/2023]
Abstract
Dysregulated mitophagy has been linked to Parkinson's disease (PD) due to the role of PTEN-induced kinase 1 (PINK1) in mediating depolarization-induced mitophagy in vitro. Elegant mouse reporters have revealed the pervasive nature of basal mitophagy in vivo, yet the role of PINK1 and tissue metabolic context remains unknown. Using mito-QC, we investigated the contribution of PINK1 to mitophagy in metabolically active tissues. We observed a high degree of mitophagy in neural cells, including PD-relevant mesencephalic dopaminergic neurons and microglia. In all tissues apart from pancreatic islets, loss of Pink1 did not influence basal mitophagy, despite disrupting depolarization-induced Parkin activation. Our findings provide the first in vivo evidence that PINK1 is detectable at basal levels and that basal mammalian mitophagy occurs independently of PINK1. This suggests multiple, yet-to-be-discovered pathways orchestrating mammalian mitochondrial integrity in a context-dependent fashion, and this has profound implications for our molecular understanding of vertebrate mitophagy.
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Affiliation(s)
- Thomas G McWilliams
- MRC Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Dundee DD1 5EH, UK.
| | - Alan R Prescott
- Dundee Imaging Facility, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Lambert Montava-Garriga
- MRC Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Dundee DD1 5EH, UK
| | - Graeme Ball
- Dundee Imaging Facility, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - François Singh
- MRC Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Dundee DD1 5EH, UK
| | - Erica Barini
- MRC Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Dundee DD1 5EH, UK
| | - Miratul M K Muqit
- MRC Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Dundee DD1 5EH, UK; School of Medicine, University of Dundee, Dundee, DD1 9SY, UK
| | - Simon P Brooks
- The Brain Repair Group, Division of Neuroscience, School of Biosciences, Cardiff University, Cardiff CF10 3AX, UK
| | - Ian G Ganley
- MRC Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Dundee DD1 5EH, UK.
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22
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Fernandez-Alonso R, Davidson L, Hukelmann J, Zengerle M, Prescott AR, Lamond A, Ciulli A, Sapkota GP, Findlay GM. Brd4-Brd2 isoform switching coordinates pluripotent exit and Smad2-dependent lineage specification. EMBO Rep 2017; 18:1108-1122. [PMID: 28588073 PMCID: PMC5494510 DOI: 10.15252/embr.201643534] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Revised: 04/15/2017] [Accepted: 04/24/2017] [Indexed: 12/04/2022] Open
Abstract
Pluripotent stem cells (PSCs) hold great clinical potential, as they possess the capacity to differentiate into fully specialised tissues such as pancreas, liver, neurons and cardiac muscle. However, the molecular mechanisms that coordinate pluripotent exit with lineage specification remain poorly understood. To address this question, we perform a small molecule screen to systematically identify novel regulators of the Smad2 signalling network, a key determinant of PSC fate. We reveal an essential function for BET family bromodomain proteins in Smad2 activation, distinct from the role of Brd4 in pluripotency maintenance. Mechanistically, BET proteins specifically engage Nodal gene regulatory elements (NREs) to promote Nodal signalling and Smad2 developmental responses. In pluripotent cells, Brd2‐Brd4 occupy NREs, but only Brd4 is required for pluripotency gene expression. Brd4 downregulation facilitates pluripotent exit and drives enhanced Brd2 NRE occupancy, thereby unveiling a specific function for Brd2 in differentiative Nodal‐Smad2 signalling. Therefore, distinct BET functionalities and Brd4‐Brd2 isoform switching at NREs coordinate pluripotent exit with lineage specification.
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Affiliation(s)
- Rosalia Fernandez-Alonso
- The MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, The University of Dundee, Dundee, UK
| | - Lindsay Davidson
- Pluripotent Stem Cell Facility, School of Life Sciences, The University of Dundee, Dundee, UK
| | - Jens Hukelmann
- Centre for Gene Regulation and Expression, School of Life Sciences, The University of Dundee, Dundee, UK
| | - Michael Zengerle
- Biological Chemistry and Drug Discovery, School of Life Sciences, The University of Dundee, Dundee, UK
| | - Alan R Prescott
- Centre for Gene Regulation and Expression, School of Life Sciences, The University of Dundee, Dundee, UK
| | - Angus Lamond
- Centre for Gene Regulation and Expression, School of Life Sciences, The University of Dundee, Dundee, UK
| | - Alessio Ciulli
- Biological Chemistry and Drug Discovery, School of Life Sciences, The University of Dundee, Dundee, UK
| | - Gopal P Sapkota
- The MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, The University of Dundee, Dundee, UK
| | - Greg M Findlay
- The MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, The University of Dundee, Dundee, UK
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23
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McWilliams TG, Prescott AR, Allen GFG, Tamjar J, Munson MJ, Thomson C, Muqit MMK, Ganley IG. mito-QC illuminates mitophagy and mitochondrial architecture in vivo. J Cell Biol 2016; 214:333-45. [PMID: 27458135 PMCID: PMC4970326 DOI: 10.1083/jcb.201603039] [Citation(s) in RCA: 320] [Impact Index Per Article: 40.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 07/06/2016] [Indexed: 11/22/2022] Open
Abstract
Whether mitophagy occurs within specific cellular subtypes in vivo is unclear. McWilliams et al. present “mito-QC,” a transgenic mouse containing a pH-sensitive fluorescent mitochondrial signal, allowing in vivo detection of mitophagy and mitochondrial morphology at single-cell resolution. Autophagic turnover of mitochondria, termed mitophagy, is proposed to be an essential quality-control (QC) mechanism of pathophysiological relevance in mammals. However, if and how mitophagy proceeds within specific cellular subtypes in vivo remains unclear, largely because of a lack of tractable tools and models. To address this, we have developed “mito-QC,” a transgenic mouse with a pH-sensitive fluorescent mitochondrial signal. This allows the assessment of mitophagy and mitochondrial architecture in vivo. Using confocal microscopy, we demonstrate that mito-QC is compatible with classical and contemporary techniques in histochemistry and allows unambiguous in vivo detection of mitophagy and mitochondrial morphology at single-cell resolution within multiple organ systems. Strikingly, our model uncovers highly enriched and differential zones of mitophagy in the developing heart and within specific cells of the adult kidney. mito-QC is an experimentally advantageous tool of broad relevance to cell biology researchers within both discovery-based and translational research communities.
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Affiliation(s)
- Thomas G McWilliams
- Medical Research Council Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Dundee DD1 9SY, Scotland, UK
| | - Alan R Prescott
- Division of Cell Signalling and Immunology, University of Dundee, Dundee DD1 9SY, Scotland, UK Dundee Imaging Facility, School of Life Sciences, University of Dundee, Dundee DD1 9SY, Scotland, UK
| | - George F G Allen
- Medical Research Council Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Dundee DD1 9SY, Scotland, UK
| | - Jevgenia Tamjar
- Medical Research Council Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Dundee DD1 9SY, Scotland, UK
| | - Michael J Munson
- Medical Research Council Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Dundee DD1 9SY, Scotland, UK
| | - Calum Thomson
- Dundee Imaging Facility, School of Life Sciences, University of Dundee, Dundee DD1 9SY, Scotland, UK
| | - Miratul M K Muqit
- Medical Research Council Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Dundee DD1 9SY, Scotland, UK School of Medicine, University of Dundee, Dundee DD1 9SY, Scotland, UK
| | - Ian G Ganley
- Medical Research Council Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Dundee DD1 9SY, Scotland, UK
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24
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Hoxhaj G, Caddye E, Najafov A, Houde VP, Johnson C, Dissanayake K, Toth R, Campbell DG, Prescott AR, MacKintosh C. The E3 ubiquitin ligase ZNRF2 is a substrate of mTORC1 and regulates its activation by amino acids. eLife 2016; 5. [PMID: 27244671 PMCID: PMC4889327 DOI: 10.7554/elife.12278] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Accepted: 03/28/2016] [Indexed: 12/22/2022] Open
Abstract
The mechanistic Target of Rapamycin complex 1 (mTORC1) senses intracellular amino acid levels through an intricate machinery, which includes the Rag GTPases, Ragulator and vacuolar ATPase (V-ATPase). The membrane-associated E3 ubiquitin ligase ZNRF2 is released into the cytosol upon its phosphorylation by Akt. In this study, we show that ZNRF2 interacts with mTOR on membranes, promoting the amino acid-stimulated translocation of mTORC1 to lysosomes and its activation in human cells. ZNRF2 also interacts with the V-ATPase and preserves lysosomal acidity. Moreover, knockdown of ZNRF2 decreases cell size and cell proliferation. Upon growth factor and amino acid stimulation, mTORC1 phosphorylates ZNRF2 on Ser145, and this phosphosite is dephosphorylated by protein phosphatase 6. Ser145 phosphorylation stimulates vesicle-to-cytosol translocation of ZNRF2 and forms a novel negative feedback on mTORC1. Our findings uncover ZNRF2 as a component of the amino acid sensing machinery that acts upstream of Rag-GTPases and the V-ATPase to activate mTORC1. DOI:http://dx.doi.org/10.7554/eLife.12278.001 During digestion, proteins are broken down into their constituent parts called amino acids. Amino acids are transported in the bloodstream and are used to build up new cells and repair old ones. Optimal regulation of the cellular rates of amino acid uptake and protein synthesis is critical to the overall health of our bodies. Inside each of our cells is a molecule called mammalian target of rapamycin (mTOR for short), which acts as a controller that receives information about amino acid availability. mTOR also senses how much of each amino acid the cell needs and calibrates the cell’s amino acid uptake and protein synthesis machineries accordingly. When investigating an enzyme named ZNRF2, Hoxhaj et al. discovered that it interacts with mTOR on membranes inside cells. This raised questions about how ZNRF2 might work with mTOR to sense amino acid supplies and regulate cell growth. Hoxhaj et al. found that when cells are provided with amino acids and growth-stimulating hormones, mTOR is activated and attaches a phosphate group to ZNRF2. This chemical modification promotes the release of ZNRF2 from membranes so that ZNRF2 separates from mTOR. In contrast, when cells are starved of amino acids, this phosphate group is removed from ZNRF2, which then returns to the membranes. On membranes, ZNRF2 also influences the activity of a pump called V-ATPase, which controls the internal acidity of the membrane-enclosed vesicles named lysosomes that help to recycle amino acids inside cells. The action of ZNRF2 on the pump may help to prime mTOR so that it is ready to sense amino acids. These findings by Hoxhaj et al. suggest that ZNRF2 and mTOR may ‘tune’ each other, making constant to-and-fro adjustments to help ensure that levels of amino acid uptake and cell growth are set just right. However, many questions about ZNRF2 still remain to be addressed. For example, are genetic mutations in ZNRF2 involved in cancers, developmental disorders or growth syndromes? Is ZNRF2 most important in the brain, where it is particularly abundant? And how does ZNRF2 affect acidity within the lysosomes? DOI:http://dx.doi.org/10.7554/eLife.12278.002
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Affiliation(s)
- Gerta Hoxhaj
- MRC Protein Phosphorylation Unit, School of Life Sciences, University of Dundee, Dundee, United Kingdom.,Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, United States
| | - Edward Caddye
- MRC Protein Phosphorylation Unit, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Ayaz Najafov
- MRC Protein Phosphorylation Unit, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Vanessa P Houde
- MRC Protein Phosphorylation Unit, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Catherine Johnson
- MRC Protein Phosphorylation Unit, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Kumara Dissanayake
- MRC Protein Phosphorylation Unit, School of Life Sciences, University of Dundee, Dundee, United Kingdom.,Cell and Developmental Biology Division, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Rachel Toth
- MRC Protein Phosphorylation Unit, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - David G Campbell
- MRC Protein Phosphorylation Unit, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Alan R Prescott
- Cell Signalling and Immunology Division, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Carol MacKintosh
- MRC Protein Phosphorylation Unit, School of Life Sciences, University of Dundee, Dundee, United Kingdom.,Cell and Developmental Biology Division, School of Life Sciences, University of Dundee, Dundee, United Kingdom
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25
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Zaru R, Matthews SP, Edgar AJ, Prescott AR, Gomez-Nicola D, Hanauer A, Watts C. The PDK1-Rsk Signaling Pathway Controls Langerhans Cell Proliferation and Patterning. J Immunol 2015; 195:4264-72. [PMID: 26401001 PMCID: PMC4640173 DOI: 10.4049/jimmunol.1501520] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Accepted: 08/26/2015] [Indexed: 12/12/2022]
Abstract
Langerhans cells (LC), the dendritic cells of the epidermis, are distributed in a distinctive regularly spaced array. In the mouse, the LC array is established in the first few days of life from proliferating local precursors, but the regulating signaling pathways are not fully understood. We found that mice lacking the kinase phosphoinositide-dependent kinase 1 selectively lack LC. Deletion of the phosphoinositide-dependent kinase 1 target kinases, ribosomal S6 kinase 1 (Rsk1) and Rsk2, produced a striking perturbation in the LC network: LC density was reduced 2-fold, but LC size was increased by the same magnitude. Reduced LC numbers in Rsk1/2(-/-) mice was not due to accelerated emigration from the skin but rather to reduced proliferation at least in adults. Rsk1/2 were required for normal LC patterning in neonates, but not when LC were ablated in adults and replaced by bone marrow-derived cells. Increased LC size was an intrinsic response to reduced LC numbers, reversible on LC emigration, and could be observed in wild type epidermis where LC size also correlated inversely with LC density. Our results identify a key signaling pathway needed to establish a normal LC network and suggest that LC might maintain epidermal surveillance by increasing their "footprint" when their numbers are limited.
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Affiliation(s)
- Rossana Zaru
- Division of Cell Signaling and Immunology, College of Life Science, University of Dundee, Dundee DD1 5EH, United Kingdom
| | - Stephen P Matthews
- Division of Cell Signaling and Immunology, College of Life Science, University of Dundee, Dundee DD1 5EH, United Kingdom
| | - Alexander J Edgar
- Division of Cell Signaling and Immunology, College of Life Science, University of Dundee, Dundee DD1 5EH, United Kingdom
| | - Alan R Prescott
- Division of Cell Signaling and Immunology, College of Life Science, University of Dundee, Dundee DD1 5EH, United Kingdom
| | - Diego Gomez-Nicola
- Centre for Biological Sciences, University of Southampton, Southampton General Hospital, Southampton SO16 6YD, United Kingdom; and
| | - André Hanauer
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Centre National de la Recherche Scientifique Unite Mixté de Recherche 7104, INSERM U 964, University of Strasbourg, 67404 Illkirch, France
| | - Colin Watts
- Division of Cell Signaling and Immunology, College of Life Science, University of Dundee, Dundee DD1 5EH, United Kingdom;
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26
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Kazlauskaite A, Martínez-Torres RJ, Wilkie S, Kumar A, Peltier J, Gonzalez A, Johnson C, Zhang J, Hope AG, Peggie M, Trost M, van Aalten DMF, Alessi DR, Prescott AR, Knebel A, Walden H, Muqit MMK. Binding to serine 65-phosphorylated ubiquitin primes Parkin for optimal PINK1-dependent phosphorylation and activation. EMBO Rep 2015; 16:939-54. [PMID: 26116755 PMCID: PMC4552487 DOI: 10.15252/embr.201540352] [Citation(s) in RCA: 158] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 06/10/2015] [Indexed: 02/05/2023] Open
Abstract
Mutations in the mitochondrial protein kinase PINK1 are associated with autosomal recessive Parkinson disease (PD). We and other groups have reported that PINK1 activates Parkin E3 ligase activity both directly via phosphorylation of Parkin serine 65 (Ser(65))--which lies within its ubiquitin-like domain (Ubl)--and indirectly through phosphorylation of ubiquitin at Ser(65). How Ser(65)-phosphorylated ubiquitin (ubiquitin(Phospho-Ser65)) contributes to Parkin activation is currently unknown. Here, we demonstrate that ubiquitin(Phospho-Ser65) binding to Parkin dramatically increases the rate and stoichiometry of Parkin phosphorylation at Ser(65) by PINK1 in vitro. Analysis of the Parkin structure, corroborated by site-directed mutagenesis, shows that the conserved His302 and Lys151 residues play a critical role in binding of ubiquitin(Phospho-Ser65), thereby promoting Parkin Ser(65) phosphorylation and activation of its E3 ligase activity in vitro. Mutation of His302 markedly inhibits Parkin Ser(65) phosphorylation at the mitochondria, which is associated with a marked reduction in its E3 ligase activity following mitochondrial depolarisation. We show that the binding of ubiquitin(Phospho-Ser65) to Parkin disrupts the interaction between the Ubl domain and C-terminal region, thereby increasing the accessibility of Parkin Ser(65). Finally, purified Parkin maximally phosphorylated at Ser(65) in vitro cannot be further activated by the addition of ubiquitin(Phospho-Ser65). Our results thus suggest that a major role of ubiquitin(Phospho-Ser65) is to promote PINK1-mediated phosphorylation of Parkin at Ser(65), leading to maximal activation of Parkin E3 ligase activity. His302 and Lys151 are likely to line a phospho-Ser(65)-binding pocket on the surface of Parkin that is critical for the ubiquitin(Phospho-Ser65) interaction. This study provides new mechanistic insights into Parkin activation by ubiquitin(Phospho-Ser65), which could aid in the development of Parkin activators that mimic the effect of ubiquitin(Phospho-Ser65).
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Affiliation(s)
- Agne Kazlauskaite
- MRC Protein Phosphorylation and Ubiquitylation Unit, College of Life Sciences University of Dundee, Dundee, UK
| | - R Julio Martínez-Torres
- MRC Protein Phosphorylation and Ubiquitylation Unit, College of Life Sciences University of Dundee, Dundee, UK
| | - Scott Wilkie
- Division of Biological Chemistry and Drug Discovery, College of Life Sciences University of Dundee, Dundee, UK
| | - Atul Kumar
- MRC Protein Phosphorylation and Ubiquitylation Unit, College of Life Sciences University of Dundee, Dundee, UK
| | - Julien Peltier
- MRC Protein Phosphorylation and Ubiquitylation Unit, College of Life Sciences University of Dundee, Dundee, UK
| | - Alba Gonzalez
- MRC Protein Phosphorylation and Ubiquitylation Unit, College of Life Sciences University of Dundee, Dundee, UK
| | - Clare Johnson
- MRC Protein Phosphorylation and Ubiquitylation Unit, College of Life Sciences University of Dundee, Dundee, UK
| | - Jinwei Zhang
- MRC Protein Phosphorylation and Ubiquitylation Unit, College of Life Sciences University of Dundee, Dundee, UK
| | - Anthony G Hope
- Division of Biological Chemistry and Drug Discovery, College of Life Sciences University of Dundee, Dundee, UK
| | - Mark Peggie
- MRC Protein Phosphorylation and Ubiquitylation Unit, College of Life Sciences University of Dundee, Dundee, UK
| | - Matthias Trost
- MRC Protein Phosphorylation and Ubiquitylation Unit, College of Life Sciences University of Dundee, Dundee, UK
| | - Daan M F van Aalten
- MRC Protein Phosphorylation and Ubiquitylation Unit, College of Life Sciences University of Dundee, Dundee, UK
| | - Dario R Alessi
- MRC Protein Phosphorylation and Ubiquitylation Unit, College of Life Sciences University of Dundee, Dundee, UK
| | - Alan R Prescott
- Division of Cell Signalling and Immunology, College of Life Sciences University of Dundee, Dundee, UK
| | - Axel Knebel
- MRC Protein Phosphorylation and Ubiquitylation Unit, College of Life Sciences University of Dundee, Dundee, UK
| | - Helen Walden
- MRC Protein Phosphorylation and Ubiquitylation Unit, College of Life Sciences University of Dundee, Dundee, UK
| | - Miratul M K Muqit
- MRC Protein Phosphorylation and Ubiquitylation Unit, College of Life Sciences University of Dundee, Dundee, UK College of Medicine, Dentistry & Nursing University of Dundee, Dundee, UK
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Martin-Granados C, Prescott AR, Le Sommer S, Klaska IP, Yu T, Muckersie E, Giuraniuc CV, Grant L, Delibegovic M, Forrester JV. A key role for PTP1B in dendritic cell maturation, migration, and T cell activation. J Mol Cell Biol 2015; 7:517-28. [PMID: 26063615 DOI: 10.1093/jmcb/mjv032] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Accepted: 03/08/2015] [Indexed: 12/15/2022] Open
Abstract
Dendritic cells (DC) are the major antigen-presenting cells bridging innate and adaptive immunity, a function they perform by converting quiescent DC to active, mature DC with the capacity to activate naïve T cells. They do this by migrating from the tissues to the T cell area of the secondary lymphoid tissues. Here, we demonstrate that myeloid cell-specific genetic deletion of PTP1B (LysM PTP1B) leads to defects in lipopolysaccharide-driven bone marrow-derived DC (BMDC) activation associated with increased levels of phosphorylated Stat3. We show that myeloid cell-specific PTP1B deletion also causes decreased migratory capacity of epidermal DC, as well as reduced CCR7 expression and chemotaxis to CCL19 by BMDC. PTP1B deficiency in BMDC also impairs their migration in vivo. Further, immature LysM PTP1B BMDC display fewer podosomes, increased levels of phosphorylated Src at tyrosine 527, and loss of Src localization to podosome puncta. In co-culture with T cells, LysM PTP1B BMDC establish fewer and shorter contacts than control BMDC. Finally, LysM PTP1B BMDC fail to present antigen to T cells as efficiently as control BMDC. These data provide first evidence for a key regulatory role for PTP1B in mediating a central DC function of initiating adaptive immune responses in response to innate immune cell activation.
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Affiliation(s)
- Cristina Martin-Granados
- Institute of Medical Sciences, University of Aberdeen, College of Life Sciences and Medicine, Aberdeen AB25 2ZD, UK Department of Pharmacology, University of Cambridge, Cambridge CB2 1PD, UK
| | - Alan R Prescott
- Division of Cell Biology and Immunology, College of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Samantha Le Sommer
- Institute of Medical Sciences, University of Aberdeen, College of Life Sciences and Medicine, Aberdeen AB25 2ZD, UK
| | - Izabela P Klaska
- Institute of Medical Sciences, University of Aberdeen, College of Life Sciences and Medicine, Aberdeen AB25 2ZD, UK
| | - Tian Yu
- Institute of Medical Sciences, University of Aberdeen, College of Life Sciences and Medicine, Aberdeen AB25 2ZD, UK
| | - Elizabeth Muckersie
- Institute of Medical Sciences, University of Aberdeen, College of Life Sciences and Medicine, Aberdeen AB25 2ZD, UK
| | - Claudiu V Giuraniuc
- Institute of Medical Sciences, University of Aberdeen, College of Life Sciences and Medicine, Aberdeen AB25 2ZD, UK
| | - Louise Grant
- Institute of Medical Sciences, University of Aberdeen, College of Life Sciences and Medicine, Aberdeen AB25 2ZD, UK
| | - Mirela Delibegovic
- Institute of Medical Sciences, University of Aberdeen, College of Life Sciences and Medicine, Aberdeen AB25 2ZD, UK
| | - John V Forrester
- Institute of Medical Sciences, University of Aberdeen, College of Life Sciences and Medicine, Aberdeen AB25 2ZD, UK Centre for Ophthalmology and Visual Science, The University of Western Australia, Perth, Australia Centre for Experimental Immunology, Lions Eye Institute, Nedlands, WA 6009, Australia
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Guo M, Härtlova A, Dill BD, Prescott AR, Gierliński M, Trost M. High-resolution quantitative proteome analysis reveals substantial differences between phagosomes of RAW 264.7 and bone marrow derived macrophages. Proteomics 2015; 15:3169-74. [PMID: 25504905 PMCID: PMC4833182 DOI: 10.1002/pmic.201400431] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Revised: 09/08/2014] [Accepted: 12/08/2014] [Indexed: 12/31/2022]
Abstract
Macrophages are important immune cells operating at the forefront of innate immunity by taking up foreign particles and microbes through phagocytosis. The RAW 264.7 cell line is commonly used for experiments in the macrophage and phagocytosis field. However, little is known how its functions compare to primary macrophages. Here, we have performed an in‐depth proteomics characterization of phagosomes from RAW 264.7 and bone marrow derived macrophages by quantifying more than 2500 phagosomal proteins. Our data indicate that there are significant differences for a large number of proteins including important receptors such as mannose receptor 1 and Siglec‐1. Moreover, bone marrow derived macrophages phagosomes mature considerably faster by fusion with endosomes and the lysosome which we validated using fluorogenic phagocytic assays. We provide a valuable resource for researcher in the field and recommend careful use of the RAW 264.7 cell line when studying phagosome functions. All MS data have been deposited in the ProteomeXchange with identifier PXD001293 (http://proteomecentral.proteomexchange.org/dataset/PXD001293).
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Affiliation(s)
- Manman Guo
- MRC Protein Phosphorylation and Ubiquitylation Unit, College of Life Science, University of Dundee, Scotland, UK
| | - Anetta Härtlova
- MRC Protein Phosphorylation and Ubiquitylation Unit, College of Life Science, University of Dundee, Scotland, UK
| | - Brian D Dill
- MRC Protein Phosphorylation and Ubiquitylation Unit, College of Life Science, University of Dundee, Scotland, UK
| | - Alan R Prescott
- Division of Cell Signalling and Immunology, College of Life Science, University of Dundee, Scotland, UK
| | - Marek Gierliński
- Division of Computational Biology, College of Life Sciences, University of Dundee, Scotland, UK
| | - Matthias Trost
- MRC Protein Phosphorylation and Ubiquitylation Unit, College of Life Science, University of Dundee, Scotland, UK
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Saunders SP, Goh CS, Brown SJ, Palmer CN, Porter RM, Cole C, Campbell LE, Gierlinski M, Barton GJ, Schneider G, Balmain A, Prescott AR, Weidinger S, Baurecht H, Kabesch M, Gieger C, Lee YA, Tavendale R, Mukhopadhyay S, Turner SW, Madhok VB, Sullivan FM, Relton C, Burn J, Meggitt S, Smith CH, Allen MA, Barker JNN, Reynolds NJ, Cordell HJ, Irvine AD, McLean WI, Sandilands A, Fallon PG. Tmem79/Matt is the matted mouse gene and is a predisposing gene for atopic dermatitis in human subjects. J Allergy Clin Immunol 2013; 132:1121-9. [PMID: 24084074 PMCID: PMC3834151 DOI: 10.1016/j.jaci.2013.08.046] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Revised: 08/15/2013] [Accepted: 08/16/2013] [Indexed: 02/07/2023]
Abstract
BACKGROUND Atopic dermatitis (AD) is a major inflammatory condition of the skin caused by inherited skin barrier deficiency, with mutations in the filaggrin gene predisposing to development of AD. Support for barrier deficiency initiating AD came from flaky tail mice, which have a frameshift mutation in Flg and also carry an unknown gene, matted, causing a matted hair phenotype. OBJECTIVE We sought to identify the matted mutant gene in mice and further define whether mutations in the human gene were associated with AD. METHODS A mouse genetics approach was used to separate the matted and Flg mutations to produce congenic single-mutant strains for genetic and immunologic analysis. Next-generation sequencing was used to identify the matted gene. Five independently recruited AD case collections were analyzed to define associations between single nucleotide polymorphisms (SNPs) in the human gene and AD. RESULTS The matted phenotype in flaky tail mice is due to a mutation in the Tmem79/Matt gene, with no expression of the encoded protein mattrin in the skin of mutant mice. Matt(ft) mice spontaneously have dermatitis and atopy caused by a defective skin barrier, with mutant mice having systemic sensitization after cutaneous challenge with house dust mite allergens. Meta-analysis of 4,245 AD cases and 10,558 population-matched control subjects showed that a missense SNP, rs6684514, [corrected] in the human MATT gene has a small but significant association with AD. CONCLUSION In mice mutations in Matt cause a defective skin barrier and spontaneous dermatitis and atopy. A common SNP in MATT has an association with AD in human subjects.
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Affiliation(s)
- Sean P. Saunders
- School of Medicine, Trinity College Dublin, Dublin, Ireland
- National Children's Research Centre, Our Lady's Children's Hospital, Dublin, Ireland
- Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland
| | - Christabelle S.M. Goh
- Centre for Dermatology and Genetic Medicine, University of Dundee, Dundee, United Kingdom
| | - Sara J. Brown
- Centre for Dermatology and Genetic Medicine, University of Dundee, Dundee, United Kingdom
| | - Colin N.A. Palmer
- Biomedical Research Institute, University of Dundee, Dundee, United Kingdom
| | - Rebecca M. Porter
- School of Medicine, Trinity College Dublin, Dublin, Ireland
- Centre for Dermatology and Genetic Medicine, University of Dundee, Dundee, United Kingdom
| | - Christian Cole
- Centre for Dermatology and Genetic Medicine, University of Dundee, Dundee, United Kingdom
- Bioinformatics Research Group, University of Dundee, Dundee, United Kingdom
| | - Linda E. Campbell
- Centre for Dermatology and Genetic Medicine, University of Dundee, Dundee, United Kingdom
| | - Marek Gierlinski
- Bioinformatics Research Group, University of Dundee, Dundee, United Kingdom
| | - Geoffrey J. Barton
- Bioinformatics Research Group, University of Dundee, Dundee, United Kingdom
| | | | - Allan Balmain
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, Calif
| | - Alan R. Prescott
- Division of Cell Signalling and Immunology, University of Dundee, Dundee, United Kingdom
| | - Stephan Weidinger
- Department of Dermatology, Allergy, and Venerology, University Hospital Schleswig-Holstein, Kiel, Germany
| | - Hansjörg Baurecht
- Department of Dermatology, Allergy, and Venerology, University Hospital Schleswig-Holstein, Kiel, Germany
| | - Michael Kabesch
- Department of Pediatric Pneumology and Allergy, Children's Hospital Regensburg, Regensburg, Germany
| | - Christian Gieger
- Institute of Genetic Epidemiology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Young-Ae Lee
- Pediatric Pneumology and Immunology, Charité University Medicine Berlin and Max Delbrück Center for Molecular Medicine (MDC) Berlin-Buch, Berlin, Germany
| | - Roger Tavendale
- Biomedical Research Institute, University of Dundee, Dundee, United Kingdom
| | - Somnath Mukhopadhyay
- Academic Department of Paediatrics, Royal Alexandra Children's Hospital, Brighton and Sussex Medical School, Brighton, United Kingdom
| | - Stephen W. Turner
- Department of Child Health, University of Aberdeen, Aberdeen, United Kingdom
| | - Vishnu B. Madhok
- Population Health Sciences, University of Dundee, Dundee, United Kingdom
| | - Frank M. Sullivan
- Population Health Sciences, University of Dundee, Dundee, United Kingdom
| | - Caroline Relton
- Institute of Genetic Medicine, Newcastle University, Newcastle, United Kingdom
| | - John Burn
- Institute of Genetic Medicine, Newcastle University, Newcastle, United Kingdom
| | - Simon Meggitt
- Department of Dermatology, Royal Victoria Infirmary, Newcastle upon Tyne, United Kingdom
| | - Catherine H. Smith
- St John's Institute of Dermatology, King's College London, London, United Kingdom
| | - Michael A. Allen
- St John's Institute of Dermatology, King's College London, London, United Kingdom
| | | | - Nick J. Reynolds
- Institute of Cellular Medicine, Newcastle University, Newcastle, United Kingdom
| | - Heather J. Cordell
- Institute of Genetic Medicine, Newcastle University, Newcastle, United Kingdom
| | - Alan D. Irvine
- School of Medicine, Trinity College Dublin, Dublin, Ireland
- National Children's Research Centre, Our Lady's Children's Hospital, Dublin, Ireland
- Department of Paediatric Dermatology, Our Lady's Children's Hospital, Crumlin, Dublin, Ireland
| | - W.H. Irwin McLean
- Centre for Dermatology and Genetic Medicine, University of Dundee, Dundee, United Kingdom
| | - Aileen Sandilands
- Centre for Dermatology and Genetic Medicine, University of Dundee, Dundee, United Kingdom
| | - Padraic G. Fallon
- School of Medicine, Trinity College Dublin, Dublin, Ireland
- National Children's Research Centre, Our Lady's Children's Hospital, Dublin, Ireland
- Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland
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Sargent F, Davidson FA, Kelly CL, Binny R, Christodoulides N, Gibson D, Johansson E, Kozyrska K, Lado LL, MacCallum J, Montague R, Ortmann B, Owen R, Coulthurst SJ, Dupuy L, Prescott AR, Palmer T. A synthetic system for expression of components of a bacterial microcompartment. Microbiology (Reading) 2013; 159:2427-2436. [PMID: 24014666 PMCID: PMC3836489 DOI: 10.1099/mic.0.069922-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In general, prokaryotes are considered to be single-celled organisms that lack internal membrane-bound organelles. However, many bacteria produce proteinaceous microcompartments that serve a similar purpose, i.e. to concentrate specific enzymic reactions together or to shield the wider cytoplasm from toxic metabolic intermediates. In this paper, a synthetic operon encoding the key structural components of a microcompartment was designed based on the genes for the Salmonella propanediol utilization (Pdu) microcompartment. The genes chosen included pduA, -B, -J, -K, -N, -T and -U, and each was shown to produce protein in an Escherichia coli chassis. In parallel, a set of compatible vectors designed to express non-native cargo proteins was also designed and tested. Engineered hexa-His tags allowed isolation of the components of the microcompartments together with co-expressed, untagged, cargo proteins. Finally, an in vivo protease accessibility assay suggested that a PduD–GFP fusion could be protected from proteolysis when co-expressed with the synthetic microcompartment operon. This work gives encouragement that it may be possible to harness the genes encoding a non-native microcompartment for future biotechnological applications.
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Affiliation(s)
- Frank Sargent
- College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, UK
| | - Fordyce A Davidson
- Division of Mathematics, College of Art, Science & Engineering, University of Dundee, Dundee DD1 4HN, Scotland, UK
| | - Ciarán L Kelly
- College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, UK
| | - Rachelle Binny
- Division of Mathematics, College of Art, Science & Engineering, University of Dundee, Dundee DD1 4HN, Scotland, UK.,College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, UK
| | | | - David Gibson
- School of Computing, College of Art, Science & Engineering, University of Dundee, Dundee DD1 4HN, Scotland, UK
| | - Emelie Johansson
- College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, UK
| | - Katarzyna Kozyrska
- College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, UK
| | - Lucia Licandro Lado
- College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, UK
| | - Jane MacCallum
- College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, UK
| | - Rachel Montague
- School of Computing, College of Art, Science & Engineering, University of Dundee, Dundee DD1 4HN, Scotland, UK
| | - Brian Ortmann
- College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, UK
| | - Richard Owen
- College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, UK
| | - Sarah J Coulthurst
- College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, UK
| | - Lionel Dupuy
- Ecological Sciences, The James Hutton Institute, Invergowrie, Dundee DD2 5DA, Scotland, UK
| | - Alan R Prescott
- College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, UK
| | - Tracy Palmer
- College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, UK
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31
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Voss M, Campbell K, Saranzewa N, Campbell DG, Hastie CJ, Peggie MW, Martin-Granados C, Prescott AR, Cohen PTW. Protein phosphatase 4 is phosphorylated and inactivated by Cdk in response to spindle toxins and interacts with γ-tubulin. Cell Cycle 2013; 12:2876-87. [PMID: 23966160 PMCID: PMC3899200 DOI: 10.4161/cc.25919] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Many pharmaceuticals used to treat cancer target the cell cycle or mitotic spindle dynamics, such as the anti-tumor drug, paclitaxel, which stabilizes microtubules. Here we show that, in cells arrested in mitosis with the spindle toxins, nocodazole, or paclitaxel, the endogenous protein phosphatase 4 (Ppp4) complex Ppp4c-R2-R3A is phosphorylated on its regulatory (R) subunits, and its activity is inhibited. The phosphorylations are blocked by roscovitine, indicating that they may be mediated by Cdk1-cyclin B. Endogenous Ppp4c is enriched at the centrosomes in the absence and presence of paclitaxel, nocodazole, or roscovitine, and the activity of endogenous Ppp4c-R2-R3A is inhibited from G1/S to the G2/M phase of the cell cycle. Endogenous γ-tubulin and its associated protein, γ-tubulin complex protein 2, both of which are essential for nucleation of microtubules at centrosomes, interact with the Ppp4 complex. Recombinant γ-tubulin can be phosphorylated by Cdk1-cyclin B or Brsk1 and dephosphorylated by Ppp4c-R2-R3A in vitro. The data indicate that Ppp4c-R2-R3A regulates microtubule organization at centrosomes during cell division in response to stress signals such as spindle toxins, paclitaxel, and nocodazole, and that inhibition of the Ppp4 complex may be advantageous for treatment of some cancers.
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Affiliation(s)
- Martin Voss
- Medical Research Council Protein Phosphorylation and Ubiquitylation Unit; College of Life Sciences; University of Dundee; Dundee, Scotland, UK
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32
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Elliott JL, Der Perng M, Prescott AR, Jansen KA, Koenderink GH, Quinlan RA. The specificity of the interaction between αB-crystallin and desmin filaments and its impact on filament aggregation and cell viability. Philos Trans R Soc Lond B Biol Sci 2013; 368:20120375. [PMID: 23530264 PMCID: PMC3638400 DOI: 10.1098/rstb.2012.0375] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
CRYAB (αB-crystallin) is expressed in many tissues and yet the R120G mutation in CRYAB causes tissue-specific pathologies, namely cardiomyopathy and cataract. Here, we present evidence to demonstrate that there is a specific functional interaction of CRYAB with desmin intermediate filaments that predisposes myocytes to disease caused by the R120G mutation. We use a variety of biochemical and biophysical techniques to show that plant, animal and ascidian small heat-shock proteins (sHSPs) can interact with intermediate filaments. Nevertheless, the mutation R120G in CRYAB does specifically change that interaction when compared with equivalent substitutions in HSP27 (R140G) and into the Caenorhabditis elegans HSP16.2 (R95G). By transient transfection, we show that R120G CRYAB specifically promotes intermediate filament aggregation in MCF7 cells. The transient transfection of R120G CRYAB alone has no significant effect upon cell viability, although bundling of the endogenous intermediate filament network occurs and the mitochondria are concentrated into the perinuclear region. The combination of R120G CRYAB co-transfected with wild-type desmin, however, causes a significant reduction in cell viability. Therefore, we suggest that while there is an innate ability of sHSPs to interact with and to bind to intermediate filaments, it is the specific combination of desmin and CRYAB that compromises cell viability and this is potentially the key to the muscle pathology caused by the R120G CRYAB.
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Affiliation(s)
- Jayne L Elliott
- School of Biological and Biomedical Sciences, The University of Durham, South Road, Durham DH1 3LE, UK
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33
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MacCallum SF, Groves MJ, James J, Murray K, Appleyard V, Prescott AR, Drbal AA, Nicolaou A, Cunningham J, Haydock S, Ganley IG, Westwood NJ, Coates PJ, Lain S, Tauro S. Dysregulation of autophagy in chronic lymphocytic leukemia with the small-molecule Sirtuin inhibitor Tenovin-6. Sci Rep 2013; 3:1275. [PMID: 23429453 PMCID: PMC3572444 DOI: 10.1038/srep01275] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2012] [Accepted: 01/23/2013] [Indexed: 12/11/2022] Open
Abstract
Tenovin-6 (Tnv-6) is a bioactive small molecule with anti-neoplastic activity. Inhibition of the Sirtuin class of protein deacetylases with activation of p53 function is associated with the pro-apoptotic effects of Tnv-6 in many tumors. Here, we demonstrate that in chronic lymphocytic leukemia (CLL) cells, Tnv-6 causes non-genotoxic cytotoxicity, without adversely affecting human clonogenic hematopoietic progenitors in vitro, or murine hematopoiesis. Mechanistically, exposure of CLL cells to Tnv-6 did not induce cellular apoptosis or p53-pathway activity. Transcriptomic profiling identified a gene program influenced by Tnv-6 that included autophagy-lysosomal pathway genes. The dysregulation of autophagy was confirmed by changes in cellular ultrastructure and increases in the autophagy-regulatory proteins LC3 (LC3-II) and p62/Sequestosome. Adding bafilomycin-A1, an autophagy inhibitor to Tnv-6 containing cultures did not cause synergistic accumulation of LC3-II, suggesting inhibition of late-stage autophagy by Tnv-6. Thus, in CLL, the cytotoxic effects of Tnv-6 result from dysregulation of protective autophagy pathways.
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Affiliation(s)
- Stephanie F. MacCallum
- Dundee Cancer Centre, Ninewells Hospital, University of Dundee, Dundee, Scotland, United Kingdom DD1 9SY
- These authors contributed equally to this work
| | - Michael J. Groves
- Dundee Cancer Centre, Ninewells Hospital, University of Dundee, Dundee, Scotland, United Kingdom DD1 9SY
- These authors contributed equally to this work
| | - John James
- Cell Signalling and Immunology, College of Life Sciences, University of Dundee, Scotland, United Kingdom DD1 5EH
| | - Karen Murray
- Dundee Cancer Centre, Ninewells Hospital, University of Dundee, Dundee, Scotland, United Kingdom DD1 9SY
| | - Virginia Appleyard
- Dundee Cancer Centre, Ninewells Hospital, University of Dundee, Dundee, Scotland, United Kingdom DD1 9SY
| | - Alan R. Prescott
- Cell Signalling and Immunology, College of Life Sciences, University of Dundee, Scotland, United Kingdom DD1 5EH
| | - Abed A. Drbal
- School of Pharmacy and Centre for Skin Sciences, School of Life Sciences, University of Bradford, Bradford BD7 1DP, UK
| | - Anna Nicolaou
- School of Pharmacy and Centre for Skin Sciences, School of Life Sciences, University of Bradford, Bradford BD7 1DP, UK
| | - Joan Cunningham
- Department of Cytogenetics, Ninewells Hospital and Medical School, Dundee, Scotland, United Kingdom DD1 9SY
| | - Sally Haydock
- Department of Cytogenetics, Ninewells Hospital and Medical School, Dundee, Scotland, United Kingdom DD1 9SY
| | - Ian G. Ganley
- MRC Protein Phosphorylation Unit, College of Life Sciences, University of Dundee, Scotland, United Kingdom DD1 5EH
| | - Nicholas J. Westwood
- School of Chemistry and Biomedical Sciences Research Complex, University of St Andrews and EaStCHEM, St Andrews, Fife, UK, KY16
| | - Philip J. Coates
- Dundee Cancer Centre, Ninewells Hospital, University of Dundee, Dundee, Scotland, United Kingdom DD1 9SY
- Tayside Tissue Bank, Ninewells Hospital, University of Dundee, Dundee, Scotland, United Kingdom DD1 9SY
| | - Sonia Lain
- Dundee Cancer Centre, Ninewells Hospital, University of Dundee, Dundee, Scotland, United Kingdom DD1 9SY
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Nobels väg 16, 171 11 Stockholm, Sweden
| | - Sudhir Tauro
- Dundee Cancer Centre, Ninewells Hospital, University of Dundee, Dundee, Scotland, United Kingdom DD1 9SY
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Prescott AR, Bales A, James J, Trinkle-Mulcahy L, Sleeman JE. Time-resolved quantitative proteomics implicates the core snRNP protein, SmB, together with the Survival of Motor Neuron protein, in neural trafficking. J Cell Sci 2013; 127:812-27. [DOI: 10.1242/jcs.137703] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The biogenesis of splicing snRNPs (small nuclear ribonucleoproteins) is a complex process, beginning and ending in the nucleus of the cell but including key stages that take place in the cytoplasm. In particular, the SMN (Survival Motor Neurons) protein complex is required for addition of the core Sm proteins to the snRNP. Insufficiency of SMN results in the inherited neurodegenerative condition, Spinal Muscular Atrophy (SMA). Details of the physical organization of the cytoplasmic stages of snRNP biogenesis are unknown. We have used time-resolved quantitative proteomics to identify proteins that associate preferentially with either newly assembled or mature splicing snRNPs. These data have allowed us to identify highly mobile SmB protein trafficking vesicles in neural cells. These vesicles are dependent on the cellular levels of SMN and SmB for their morphology and mobility. We propose that these represent a family of related vesicles, some of which play a role in snRNP biogenesis and some of which may play more diverse roles in cellular RNA metabolism.
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35
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Hoxhaj G, Najafov A, Toth R, Campbell DG, Prescott AR, MacKintosh C. ZNRF2 is released from membranes by growth factors and, together with ZNRF1, regulates the Na+/K+ATPase. J Cell Sci 2012; 125:4662-75. [PMID: 22797923 DOI: 10.1242/jcs.110296] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Here, we describe a phosphorylation-based reverse myristoyl switch for mammalian ZNRF2, and show that this E3 ubiquitin ligase and its sister protein ZNRF1 regulate the Na(+)/K(+) pump (Na(+)/K(+)ATPase). N-myristoylation localizes ZNRF1 and ZNRF2 to intracellular membranes and enhances their activity. However, when ZNRF2 is phosphorylated in response to agonists including insulin and growth factors, it binds to 14-3-3 and is released into the cytosol. On membranes, ZNRF1 and ZNRF2 interact with the Na(+)/K(+)ATPase α1 subunit via their UBZ domains, while their RING domains interact with E2 proteins, predominantly Ubc13 that, together with Uev1a, mediates formation of Lys63-ubiquitin linkages. ZNRF1 and ZNRF2 can ubiquitylate the cytoplasmic loop encompassing the nucleotide-binding and phosphorylation regions of the Na(+)/K(+)ATPase α1 subunit. Ouabain, a Na(+)/K(+)ATPase inhibitor and therapeutic cardiac glycoside, decreases ZNRF1 protein levels, whereas knockdown of ZNRF2 inhibits the ouabain-induced decrease of cell surface and total Na(+)/K(+)ATPase α1 levels. Thus, ZNRF1 and ZNRF2 are new players in regulation of the ubiquitous Na(+)/K(+)ATPase that is tuned to changing demands in many physiological contexts.
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Affiliation(s)
- Gerta Hoxhaj
- MRC Protein Phosphorylation Unit, James Black Centre, College of Life Sciences, University of Dundee, Dundee DD1 5EH, UK.
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36
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Logie L, Harthill J, Patel K, Bacon S, Hamilton DL, Macrae K, McDougall G, Wang HH, Xue L, Jiang H, Sakamoto K, Prescott AR, Rena G. Cellular responses to the metal-binding properties of metformin. Diabetes 2012; 61:1423-33. [PMID: 22492524 PMCID: PMC3357267 DOI: 10.2337/db11-0961] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In recent decades, the antihyperglycemic biguanide metformin has been used extensively in the treatment of type 2 diabetes, despite continuing uncertainty over its direct target. In this article, using two independent approaches, we demonstrate that cellular actions of metformin are disrupted by interference with its metal-binding properties, which have been known for over a century but little studied by biologists. We demonstrate that copper sequestration opposes known actions of metformin not only on AMP-activated protein kinase (AMPK)-dependent signaling, but also on S6 protein phosphorylation. Biguanide/metal interactions are stabilized by extensive π-electron delocalization and by investigating analogs of metformin; we provide evidence that this intrinsic property enables biguanides to regulate AMPK, glucose production, gluconeogenic gene expression, mitochondrial respiration, and mitochondrial copper binding. In contrast, regulation of S6 phosphorylation is prevented only by direct modification of the metal-liganding groups of the biguanide structure, supporting recent data that AMPK and S6 phosphorylation are regulated independently by biguanides. Additional studies with pioglitazone suggest that mitochondrial copper is targeted by both of these clinically important drugs. Together, these results suggest that cellular effects of biguanides depend on their metal-binding properties. This link may illuminate a better understanding of the molecular mechanisms enabling antihyperglycemic drug action.
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Affiliation(s)
- Lisa Logie
- Division of Cardiovascular and Diabetes Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, Scotland, U.K
| | - Jean Harthill
- Division of Cardiovascular and Diabetes Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, Scotland, U.K
| | - Kashyap Patel
- Medical Research Council Protein Phosphorylation Unit, College of Life Sciences, University of Dundee, Dundee, Scotland, U.K
| | - Sandra Bacon
- Division of Cardiovascular and Diabetes Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, Scotland, U.K
- James Hutton Institute, Dundee, Scotland, U.K
| | - D. Lee Hamilton
- Division of Cardiovascular and Diabetes Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, Scotland, U.K
| | - Katherine Macrae
- Division of Cell Signalling and Immunology, College of Life Sciences, University of Dundee, Dundee, Scotland, U.K
| | | | - Huan-Huan Wang
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing, People’s Republic of China
| | - Lin Xue
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing, People’s Republic of China
| | - Hua Jiang
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing, People’s Republic of China
| | - Kei Sakamoto
- Medical Research Council Protein Phosphorylation Unit, College of Life Sciences, University of Dundee, Dundee, Scotland, U.K
| | - Alan R. Prescott
- Division of Cell Signalling and Immunology, College of Life Sciences, University of Dundee, Dundee, Scotland, U.K
| | - Graham Rena
- Division of Cardiovascular and Diabetes Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, Scotland, U.K
- Corresponding author: Graham Rena,
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Qu B, Landsbury A, Schönthaler HB, Dahm R, Liu Y, Clark JI, Prescott AR, Quinlan RA. Evolution of the vertebrate beaded filament protein, Bfsp2; comparing the in vitro assembly properties of a "tailed" zebrafish Bfsp2 to its "tailless" human orthologue. Exp Eye Res 2011; 94:192-202. [PMID: 22182672 DOI: 10.1016/j.exer.2011.12.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2011] [Revised: 11/30/2011] [Accepted: 12/02/2011] [Indexed: 11/25/2022]
Abstract
In bony fishes, Bfsp2 orthologues are predicted to possess a C-terminal tail domain, which is absent from avian, amphibian and mammalian Bfsp2 sequences. These sequences, are however, not conserved between fish species and therefore questions whether they have a functional role. For other intermediate filament proteins, the C-terminal tail domain is important for both filament assembly and regulating interactions between filaments. We confirm that zebrafish has a single Bfsp2 gene by radiation mapping. Two transcripts (bfsp2α and bfsp2β) are produced by alternative splicing of the last exon. Using a polyclonal antibody specific to a tridecameric peptide in the C-terminal tail domain common to both zebrafish Bfsp2 splice variants, we have confirmed its expression in zebrafish lens fibre cells. We have also determined the in vitro assembly properties of zebrafish Bfsp2α and conclude that the C-terminal sequences are required to regulate not only the diameter and uniformity of the in vitro assembly filaments, but also their filament-filament associations in vitro. Therefore we conclude zebrafish Bfsp2α is a functional orthologue conforming more closely to the conventional domain structure of intermediate filament proteins. Data mining of the genome databases suggest that the loss of this tail domain could occur in several stages leading eventually to completely tailless orthologues, such as human BFSP2.
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Dahm R, van Marle J, Quinlan RA, Prescott AR, Vrensen GFJM. Homeostasis in the vertebrate lens: mechanisms of solute exchange. Philos Trans R Soc Lond B Biol Sci 2011; 366:1265-77. [PMID: 21402585 DOI: 10.1098/rstb.2010.0299] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The eye lens is avascular, deriving nutrients from the aqueous and vitreous humours. It is, however, unclear which mechanisms mediate the transfer of solutes between these humours and the lens' fibre cells (FCs). In this review, we integrate the published data with the previously unpublished ultrastructural, dye loading and magnetic resonance imaging results. The picture emerging is that solute transfer between the humours and the fibre mass is determined by four processes: (i) paracellular transport of ions, water and small molecules along the intercellular spaces between epithelial and FCs, driven by Na(+)-leak conductance; (ii) membrane transport of such solutes from the intercellular spaces into the fibre cytoplasm by specific carriers and transporters; (iii) gap-junctional coupling mediating solute flux between superficial and deeper fibres, Na(+)/K(+)-ATPase-driven efflux of waste products in the equator, and electrical coupling of fibres; and (iv) transcellular transfer via caveoli and coated vesicles for the uptake of macromolecules and cholesterol. There is evidence that the Na(+)-driven influx of solutes occurs via paracellular and membrane transport and the Na(+)/K(+)-ATPase-driven efflux of waste products via gap junctions. This micro-circulation is likely restricted to the superficial cortex and nearly absent beyond the zone of organelle loss, forming a solute exchange barrier in the lens.
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Affiliation(s)
- Ralf Dahm
- Center for Brain Research, Medical University of Vienna, Spitalgasse 4, A-1090 Vienna, Austria.
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39
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Richardson C, Sakamoto K, de los Heros P, Deak M, Campbell DG, Prescott AR, Alessi DR. Regulation of the NKCC2 ion cotransporter by SPAK-OSR1-dependent and -independent pathways. J Cell Sci 2011; 124:789-800. [PMID: 21321328 DOI: 10.1242/jcs.077230] [Citation(s) in RCA: 135] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Ion cotransporters, such as the Na(+)/Cl(-) cotransporter (NCC), control renal salt re-absorption and are regulated by the WNK-signalling pathway, which is over-stimulated in patients suffering from Gordon's hypertension syndrome. Here, we study the regulation of the NKCC2 (SLC12A1) ion cotransporter that contributes towards ~25% of renal salt re-absorption and is inhibited by loop-diuretic hypertensive drugs. We demonstrate that hypotonic low-chloride conditions that activate the WNK1-SPAK and OSR1 pathway promote phosphorylation of NKCC2 isoforms (A, B and F) at five residues (Ser91, Thr95, Thr100, Thr105 and Ser130). We establish that the SPAK and OSR1 kinases activated by WNK interact with an RFQV motif on NKCC2 and directly phosphorylate Thr95, Thr100, Thr105 and, possibly, Ser91. Our data indicate that a SPAK-OSR1-independent kinase, perhaps AMP-activated protein kinase (AMPK), phosphorylates Ser130 and that phosphorylation of Thr105 and Ser130 plays the most important roles in stimulating NKCC2 activity. In contrast with NCC, whose membrane translocation is triggered by SPAK-OSR1 phosphorylation, NKCC2 appears to be constitutively at the membrane. Our findings provide new insights into how NKCC2 is regulated and suggest that inhibitors of SPAK and/or OSR1 for the treatment of hypertension would be therapeutically distinct from thiazide or loop diuretics, as they would suppress the activity of both NCC and NKCC2.
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Affiliation(s)
- Ciaran Richardson
- MRC Protein Phosphorylation Unit, College of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK.
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40
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Zagórska A, Deak M, Campbell DG, Banerjee S, Hirano M, Aizawa S, Prescott AR, Alessi DR. New roles for the LKB1-NUAK pathway in controlling myosin phosphatase complexes and cell adhesion. Sci Signal 2010; 3:ra25. [PMID: 20354225 DOI: 10.1126/scisignal.2000616] [Citation(s) in RCA: 126] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The AMPK-related kinases NUAK1 and NUAK2 are activated by the tumor suppressor LKB1. We found that NUAK1 interacts with several myosin phosphatases, including the myosin phosphatase targeting-1 (MYPT1)-protein phosphatase-1beta (PP1beta) complex, through conserved Gly-Ile-Leu-Lys motifs that are direct binding sites for PP1beta. Phosphorylation of Ser(445), Ser(472), and Ser(910) of MYPT1 by NUAK1 promoted the interaction of MYPT1 with 14-3-3 adaptor proteins, thereby suppressing phosphatase activity. Cell detachment induced phosphorylation of endogenous MYPT1 by NUAK1, resulting in 14-3-3 binding to MYPT1 and enhanced phosphorylation of myosin light chain-2. Inhibition of the LKB1-NUAK1 pathway impaired cell detachment. Our data indicate that NUAK1 controls cell adhesion and functions as a regulator of myosin phosphatase complexes. Thus, LKB1 can influence the phosphorylation of targets not only through the AMPK family of kinases but also by controlling phosphatase complexes.
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Affiliation(s)
- Anna Zagórska
- MRC Protein Phosphorylation Unit, College of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, Scotland, UK.
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41
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West MA, Prescott AR, Chan KM, Zhou Z, Rose-John S, Scheller J, Watts C. TLR ligand-induced podosome disassembly in dendritic cells is ADAM17 dependent. ACTA ACUST UNITED AC 2008; 182:993-1005. [PMID: 18762577 PMCID: PMC2528573 DOI: 10.1083/jcb.200801022] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Toll-like receptor (TLR) signaling induces a rapid reorganization of the actin cytoskeleton in cultured mouse dendritic cells (DC), leading to enhanced antigen endocytosis and a concomitant loss of filamentous actin-rich podosomes. We show that as podosomes are lost, TLR signaling induces prominent focal contacts and a transient reduction in DC migratory capacity in vitro. We further show that podosomes in mouse DC are foci of pronounced gelatinase activity, dependent on the enzyme membrane type I matrix metalloprotease (MT1-MMP), and that DC transiently lose the ability to degrade the extracellular matrix after TLR signaling. Surprisingly, MMP inhibitors block TLR signaling-induced podosome disassembly, although stimulated endocytosis is unaffected, which demonstrates that the two phenomena are not obligatorily coupled. Podosome disassembly caused by TLR signaling occurs normally in DC lacking MT1-MMP, and instead requires the tumor necrosis factor alpha-converting enzyme ADAM17 (a disintegrin and metalloprotease 17), which demonstrates a novel role for this "sheddase" in regulating an actin-based structure.
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Affiliation(s)
- Michele A West
- Division of Cell Biology and Immunology, Wellcome Trust Biocentre, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, UK
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42
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Rousseau S, Papoutsopoulou M, Symons A, Cook D, Lucocq JM, Prescott AR, O'Garra A, Ley SC, Cohen P. TPL2-mediated activation of ERK1 and ERK2 regulates the processing of pre-TNF alpha in LPS-stimulated macrophages. J Cell Sci 2008; 121:149-54. [PMID: 18187448 DOI: 10.1242/jcs.018671] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Activation of the TPL2-MKK1/2-ERK1/2 signalling pathway is essential for lipopolysaccharide (LPS)-stimulated production of TNF alpha in macrophages. Here, we demonstrate that, unexpectedly, TPL2-deficient or MKK1-inhibited macrophages produce near normal levels of pre-TNF alpha when TLR2, TLR4 and TLR6 are activated by their respective agonists, but fail to secrete TNFalpha. We show that LPS stimulates the appearance of pre-TNFalpha at the cell surface and that this is prevented by inhibition of MAPK kinases 1 and 2 (MKK1/2) or in TPL2-deficient macrophages. However, the transport of pre-TNF alpha from the Golgi to the plasma membrane is unaffected by inhibition of the TPL2-MKK1/2-ERK1/2 pathway. Finally, we show that TACE, the protease that cleaves pre-TNF alpha to secreted TNFalpha, is phosphorylated by ERK1 and ERK2 (ERK1/2) at Thr735 in LPS-stimulated macrophages. Therefore, although TACE activity per se is not required for the LPS-stimulated cell surface expression of pre-TNF alpha, the phosphorylation of this protease might contribute to, or be required for, the cell surface expression of the pre-TNF alpha-TACE complex.
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Affiliation(s)
- Simon Rousseau
- MRC Protein Phosphorylation Unit, College of Life Sciences, University of Dundee, Dow Street, Dundee, DD1 5EH, UK.
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Abstract
ADP-ribosylation factor 6 (ARF6) is a widely expressed GTPase that influences both membrane traffic and actin cytoskeleton function. Its role in dendritic cells (DC) has not previously been investigated. We analysed the effect of retroviral expression of ARF6 GDP/GTP binding and other functional mutants in primary murine DC. Maturation in response to lipopolysaccharide (LPS) proceeded normally in DC expressing ARF6 mutants and production of inflammatory cytokines was similarly unaffected. Although LPS-stimulated macropinocytosis was suppressed by expression of the GTP-binding Q67L ARF6 mutant we detected no overall activation of ARF6 by LPS. The ability of immature DC to migrate towards CCL3 and to a lesser extent, of mature DC to migrate towards CCL19, was compromised by expression of either the Q67L or the GDP-binding T44N mutant. Examination of the actin cytoskeleton in these cells revealed that both mutants strongly inhibited the formation of F-actin-rich podosomes, providing a possible explanation for the effects of ARF6 mutants on DC migration. Thus, these studies identify responses in DC that require normal ARF6 function, though not necessarily further ARF6 activation. They reveal for the first time a role for ARF6 in podosome formation and demonstrate functional effects of the T44N ARF6 mutant.
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Affiliation(s)
- Henrik G Svensson
- Division of Cell Biology and Immunology, School of Life Sciences, University of Dundee, Dundee, UK
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44
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Martin-Granados C, Philp A, Oxenham SK, Prescott AR, Cohen PTW. Depletion of protein phosphatase 4 in human cells reveals essential roles in centrosome maturation, cell migration and the regulation of Rho GTPases. Int J Biochem Cell Biol 2008; 40:2315-32. [PMID: 18487071 DOI: 10.1016/j.biocel.2008.03.021] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2008] [Revised: 03/28/2008] [Accepted: 03/31/2008] [Indexed: 10/22/2022]
Abstract
The mechanisms that co-ordinate centrosome maturation and the migration of human cells remain elusive. Protein phosphatase 4 (Ppp4) is a ubiquitous protein serine/threonine phosphatase in eukaryotes that is enriched at centrosomes. HEK293 cells cultures depleted to 30% Ppp4c levels by lentivirus-delivered stable gene silencing were delayed in mitosis at the prometaphase/metaphase boundary and displayed cells with aberrant chromosome organisation and microtubules unconnected to the centrosomes. The levels of alpha- and gamma-tubulin and aurora A were decreased; in mitotic cells, the cytological localisations of polo-like kinase 1, alpha- and gamma-tubulin and aurora A were aberrant and the phosphorylation of Aurora A-Thr 288 was decreased. The novel localisation of endogenous Ppp4 regulatory subunit, R3A, to centrosomes in human mitotic cells suggests that a Ppp4c-R2-R3 trimeric complex mediates centrosome maturation. We demonstrate for the first time that human cells depleted to 30% Ppp4c showed severely decreased migration and exhibit decreased levels of both total beta-actin and filamentous actin in cell extensions, filopodia and lamellopodia-like structures. Our studies show that Ppp4c is required for the organisation of the actin cytoskeleton at the leading edge of human cells during migration. We also demonstrate that the active forms of the RhoGTPases, Rac1 and Cdc42, are substantially decreased in the presence and absence of growth factor in Ppp4c depleted cells, implicating Ppp4c in the regulation of these GTPases. The results suggest that Ppp4c-R2-R3 complexes may co-ordinate centrosome maturation and cell migration via regulation of RhoGTPases and that Ppp4 may be a useful anticancer target.
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Affiliation(s)
- Cristina Martin-Granados
- Medical Research Council Protein Phosphorylation Unit, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, UK
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45
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Stokes MJ, Güther MLS, Turnock DC, Prescott AR, Martin KL, Alphey MS, Ferguson MAJ. The synthesis of UDP-N-acetylglucosamine is essential for bloodstream form trypanosoma brucei in vitro and in vivo and UDP-N-acetylglucosamine starvation reveals a hierarchy in parasite protein glycosylation. J Biol Chem 2008; 283:16147-61. [PMID: 18381290 PMCID: PMC2414269 DOI: 10.1074/jbc.m709581200] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
A gene encoding Trypanosoma brucei UDP-N-acetylglucosamine pyrophosphorylase was identified, and the recombinant protein was shown to have enzymatic activity. The parasite enzyme is unusual in having a strict substrate specificity for N-acetylglucosamine 1-phosphate and in being located inside a peroxisome-like microbody, the glycosome. A bloodstream form T. brucei conditional null mutant was constructed and shown to be unable to sustain growth in vitro or in vivo under nonpermissive conditions, demonstrating that there are no alternative metabolic or nutritional routes to UDP-N-acetylglucosamine and providing a genetic validation for the enzyme as a potential drug target. The conditional null mutant was also used to investigate the effects of N-acetylglucosamine starvation in the parasite. After 48 h under nonpermissive conditions, about 24 h before cell lysis, the status of parasite glycoprotein glycosylation was assessed. Under these conditions, UDP-N-acetylglucosamine levels were less than 5% of wild type. Lectin blotting and fluorescence microscopy with tomato lectin revealed that poly-N-acetyllactosamine structures were greatly reduced in the parasite. The principal parasite surface coat component, the variant surface glycoprotein, was also analyzed. Endoglycosidase digestions and mass spectrometry showed that, under UDP-N-acetylglucosamine starvation, the variant surface glycoprotein was specifically underglycosylated at its C-terminal Asn-428 N-glycosylation site. The significance of this finding, with respect to the hierarchy of site-specific N-glycosylation in T. brucei, is discussed.
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Affiliation(s)
- Matthew J Stokes
- Division of Biological Chemistry and Drug Discovery, The Wellcome Trust Biocentre, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, United Kingdom
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Trombone APF, Silva CL, Lima KM, Oliver C, Jamur MC, Prescott AR, Coelho-Castelo AAM. Endocytosis of DNA-Hsp65 alters the pH of the late endosome/lysosome and interferes with antigen presentation. PLoS One 2007; 2:e923. [PMID: 17895965 PMCID: PMC1976595 DOI: 10.1371/journal.pone.0000923] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2007] [Accepted: 08/30/2007] [Indexed: 11/18/2022] Open
Abstract
Background Experimental models using DNA vaccine has shown that this vaccine is efficient in generating humoral and cellular immune responses to a wide variety of DNA-derived antigens. Despite the progress in DNA vaccine development, the intracellular transport and fate of naked plasmid DNA in eukaryotic cells is poorly understood, and need to be clarified in order to facilitate the development of novel vectors and vaccine strategies. Methodology and Principal Findings Using confocal microscopy, we have demonstrated for the first time that after plasmid DNA uptake an inhibition of the acidification of the lysosomal compartment occurs. This lack of acidification impaired antigen presentation to CD4 T cells, but did not alter the recruitment of MyD88. The recruitment of Rab 5 and Lamp I were also altered since we were not able to co-localize plasmid DNA with Rab 5 and Lamp I in early endosomes and late endosomes/lysosomes, respectively. Furthermore, we observed that the DNA capture process in macrophages was by clathrin-mediated endocytosis. In addition, we observed that plasmid DNA remains in vesicles until it is in a juxtanuclear location, suggesting that the plasmid does not escape into the cytoplasmic compartment. Conclusions and Significance Taken together our data suggests a novel mechanism involved in the intracellular trafficking of plasmid DNA, and opens new possibilities for the use of lower doses of plasmid DNA to regulate the immune response.
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Affiliation(s)
- Ana Paula F. Trombone
- Department of Biochemistry and Immunology, School of Medicine of Ribeirão Preto, University of São Paulo, São Paulo, Brazil
- Brazilian Tuberculosis Research Network of School of Medicine of Ribeirão Preto, University of São Paulo, São Paulo, Brazil
| | - Célio L. Silva
- Department of Biochemistry and Immunology, School of Medicine of Ribeirão Preto, University of São Paulo, São Paulo, Brazil
- Brazilian Tuberculosis Research Network of School of Medicine of Ribeirão Preto, University of São Paulo, São Paulo, Brazil
| | - Karla M. Lima
- Department of Biochemistry and Immunology, School of Medicine of Ribeirão Preto, University of São Paulo, São Paulo, Brazil
| | - Constance Oliver
- Department of Cellular and Molecular Biology, School of Medicine of Ribeirão Preto, University of São Paulo, São Paulo, Brazil
| | - Maria Célia Jamur
- Department of Cellular and Molecular Biology, School of Medicine of Ribeirão Preto, University of São Paulo, São Paulo, Brazil
| | - Alan R. Prescott
- Division of Cell Biology and Immunology, School of Life Sciences, University of Dundee, Dundee, Scotland
| | - Arlete A. M. Coelho-Castelo
- Department of Biochemistry and Immunology, School of Medicine of Ribeirão Preto, University of São Paulo, São Paulo, Brazil
- Brazilian Tuberculosis Research Network of School of Medicine of Ribeirão Preto, University of São Paulo, São Paulo, Brazil
- * To whom correspondence should be addressed. E-mail:
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Dahm R, Procter JE, Ireland ME, Lo WK, Mogensen MM, Quinlan RA, Prescott AR. Reorganization of centrosomal marker proteins coincides with epithelial cell differentiation in the vertebrate lens. Exp Eye Res 2007; 85:696-713. [PMID: 17888905 DOI: 10.1016/j.exer.2007.07.022] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2007] [Revised: 07/26/2007] [Accepted: 07/31/2007] [Indexed: 12/24/2022]
Abstract
The differentiation of epithelial cells in the vertebrate lens involves a series of changes that includes the degradation of all intracellular organelles and a dramatic elongation of the cells. The latter is accompanied by a substantial remodelling of the cytoskeleton and changes in the distribution of the actin, microtubule and intermediate filament cytoskeletons during lens cell differentiation have been well documented. There have, however, been no studies of microtubule organizing centres (MTOCs) and specifically centrosomes during lens cell differentiation. We have investigated the fate of the centrosomal MTOCs during cellular differentiation in the bovine lens using gamma-tubulin, ninein, centrin 2 and centrin 3 as markers. Our studies show that these markers oscillate between a clear centrosome-based association in epithelial cells and a defocused cluster in lens fibre cells. Our data further reveal a transient loss of signal for the typical centrosomal marker gamma-tubulin as the lens epithelial cells begin to differentiate into lens fibre cells. This marker apparently disappears in the most distal epithelial cells at the lens equator, only to reappear in early lens fibre cells. The changes in gamma-tubulin distribution are mirrored by the other centrosomal markers, centrins 2 and 3 and ninein that also show a similar transient loss of their signals and subsequent clustering at the apical ends of differentiating fibre cells. The transient loss of staining for these centrosomal markers in the most posterior epithelial cells is a distinctive feature that precedes lens cell elongation. The dramatic reorganization of MTOC markers coincides with gap junction reorganization as seen by the loss of connexin 43 (alpha1-connexin) in these lens epithelial cells suggesting that these events mark a significant change preceding subsequent cell elongation and differentiation into fibre cells.
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Affiliation(s)
- Ralf Dahm
- Department of Biochemistry, Medical Sciences Institute, University of Dundee, Dundee, DD1 4HN, UK.
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48
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Tholozan FMD, Gribbon C, Li Z, Goldberg MW, Prescott AR, McKie N, Quinlan RA. FGF-2 release from the lens capsule by MMP-2 maintains lens epithelial cell viability. Mol Biol Cell 2007; 18:4222-31. [PMID: 17699594 PMCID: PMC2043559 DOI: 10.1091/mbc.e06-05-0416] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The lens is an avascular tissue, separated from the aqueous and vitreous humors by its own extracellular matrix, the lens capsule. Here we demonstrate that the lens capsule is a source of essential survival factors for lens epithelial cells. Primary and immortalized lens epithelial cells survive in low levels of serum and are resistant to staurosporine-induced apoptosis when they remain in contact with the lens capsule. Physical contact with the capsule is required for maximal resistance to stress. The lens capsule is also a source of soluble factors including fibroblast growth factor 2 (FGF-2) and perlecan, an extracellular matrix component that enhances FGF-2 activity. Matrix metalloproteinase 2 (MMP-2) inhibition as well as MMP-2 pretreatment of lens capsules greatly reduced the protective effect of the lens capsule, although this could be largely reversed by the addition of either conditioned medium or recombinant FGF-2. These data suggest that FGF-2 release from the lens capsule by MMP-2 is essential to lens epithelial cell viability and survival.
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Affiliation(s)
- Frederique M D Tholozan
- School of Biological and Biomedical Sciences, Durham University, Durham DH1 3LE, United Kingdom
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49
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Moss DK, Bellett G, Carter JM, Liovic M, Keynton J, Prescott AR, Lane EB, Mogensen MM. Ninein is released from the centrosome and moves bi-directionally along microtubules. J Cell Sci 2007; 120:3064-74. [PMID: 17698918 DOI: 10.1242/jcs.010322] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Cell-to-cell contact and polarisation of epithelial cells involve a major reorganisation of the microtubules and centrosomal components. The radial microtubule organisation is lost and an apico-basal array develops that is no longer anchored at the centrosome. This involves not only the relocation of microtubules but also of centrosomal anchoring proteins to apical non-centrosomal sites. The relocation of microtubule minus-end-anchoring proteins such as ninein to the apical sites is likely to be essential for the assembly and stabilisation of the apico-basal arrays in polarised epithelial cells. In this study, we establish that ninein is highly dynamic and that, in epithelial cells, it is present not only at the centrosome but also in the cytoplasm as distinct speckles. Live-cell imaging reveals that GFP-ninein speckles are released from the centrosome and move in a microtubule-dependent manner within the cytoplasm and thus establishes that epithelial cells possess the mechanical means for relocation of ninein to non-centrosomal anchoring sites. We also provide evidence for the deployment of ninein speckles to apical anchoring sites during epithelial differentiation in both an in situ tissue and an in vitro culture system. In addition, the findings suggest that the non-centrosomal microtubule anchoring sites associate with adherens junctions in polarised epithelial cells.
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Affiliation(s)
- David K Moss
- School of Biological Sciences, University of East Anglia, Norwich, NR4 7TJ, UK
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Watts C, Zaru R, Prescott AR, Wallin RP, West MA. Proximal effects of Toll-like receptor activation in dendritic cells. Curr Opin Immunol 2007; 19:73-8. [PMID: 17142025 DOI: 10.1016/j.coi.2006.11.014] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2006] [Accepted: 11/23/2006] [Indexed: 11/18/2022]
Abstract
Toll-like receptor (TLR) signals induce dendritic cell (DC) differentiation and influence the immunological outcome of their interactions with T cells. Recent in vitro studies demonstrate that TLR signals also trigger striking reorganisation of the DC vacuolar compartments, the cytoskeleton and the machinery of protein translation and turnover. Moreover, TLR ligation within endosomes and phagosomes appears to establish organelle autonomous signals. These changes, which mostly occur within minutes to a few hours after TLR engagement, are adaptations relevant to the antigen capture, processing and migratory phases of the DC life history.
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Affiliation(s)
- Colin Watts
- Division of Cell Biology and Immunology, College of Life Sciences, University of Dundee, Dundee DD1 5EH, United Kingdom.
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