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Mishra S, Manohar V, Chandel S, Manoj T, Bhattacharya S, Hegde N, Nath VR, Krishnan H, Wendling C, Di Mattia T, Martinet A, Chimata P, Alpy F, Raghu P. A genetic screen to uncover mechanisms underlying lipid transfer protein function at membrane contact sites. Life Sci Alliance 2024; 7:e202302525. [PMID: 38499328 PMCID: PMC10948934 DOI: 10.26508/lsa.202302525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 03/04/2024] [Accepted: 03/05/2024] [Indexed: 03/20/2024] Open
Abstract
Lipid transfer proteins mediate the transfer of lipids between organelle membranes, and the loss of function of these proteins has been linked to neurodegeneration. However, the mechanism by which loss of lipid transfer activity leads to neurodegeneration is not understood. In Drosophila photoreceptors, depletion of retinal degeneration B (RDGB), a phosphatidylinositol transfer protein, leads to defective phototransduction and retinal degeneration, but the mechanism by which loss of this activity leads to retinal degeneration is not understood. RDGB is localized to membrane contact sites through the interaction of its FFAT motif with the ER integral protein VAP. To identify regulators of RDGB function in vivo, we depleted more than 300 VAP-interacting proteins and identified a set of 52 suppressors of rdgB The molecular identity of these suppressors indicates a role of novel lipids in regulating RDGB function and of transcriptional and ubiquitination processes in mediating retinal degeneration in rdgB9 The human homologs of several of these molecules have been implicated in neurodevelopmental diseases underscoring the importance of VAP-mediated processes in these disorders.
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Affiliation(s)
- Shirish Mishra
- https://ror.org/03gf8rp76 National Centre for Biological Sciences-TIFR, GKVK Campus, Bangalore, India
| | - Vaishnavi Manohar
- https://ror.org/03gf8rp76 National Centre for Biological Sciences-TIFR, GKVK Campus, Bangalore, India
| | - Shabnam Chandel
- https://ror.org/03gf8rp76 National Centre for Biological Sciences-TIFR, GKVK Campus, Bangalore, India
| | - Tejaswini Manoj
- https://ror.org/03gf8rp76 National Centre for Biological Sciences-TIFR, GKVK Campus, Bangalore, India
| | - Subhodeep Bhattacharya
- https://ror.org/03gf8rp76 National Centre for Biological Sciences-TIFR, GKVK Campus, Bangalore, India
| | - Nidhi Hegde
- https://ror.org/03gf8rp76 National Centre for Biological Sciences-TIFR, GKVK Campus, Bangalore, India
| | - Vaisaly R Nath
- https://ror.org/03gf8rp76 National Centre for Biological Sciences-TIFR, GKVK Campus, Bangalore, India
- School of Biotechnology, Amrita Vishwa Vidyapeetham, Kollam, India
| | - Harini Krishnan
- https://ror.org/03gf8rp76 National Centre for Biological Sciences-TIFR, GKVK Campus, Bangalore, India
| | - Corinne Wendling
- Université de Strasbourg, CNRS, Inserm, IGBMC UMR 7104- UMR-S 1258, Illkirch, France
| | - Thomas Di Mattia
- Université de Strasbourg, CNRS, Inserm, IGBMC UMR 7104- UMR-S 1258, Illkirch, France
| | - Arthur Martinet
- Université de Strasbourg, CNRS, Inserm, IGBMC UMR 7104- UMR-S 1258, Illkirch, France
| | - Prasanth Chimata
- https://ror.org/03gf8rp76 National Centre for Biological Sciences-TIFR, GKVK Campus, Bangalore, India
| | - Fabien Alpy
- Université de Strasbourg, CNRS, Inserm, IGBMC UMR 7104- UMR-S 1258, Illkirch, France
| | - Padinjat Raghu
- https://ror.org/03gf8rp76 National Centre for Biological Sciences-TIFR, GKVK Campus, Bangalore, India
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Park K, Ju S, Choi H, Gao P, Bang G, Choi JH, Jang J, Morris AJ, Kang BH, Hsu VW, Park SY. PITPβ promotes COPI vesicle fission through lipid transfer and membrane contact formation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.27.596058. [PMID: 38853868 PMCID: PMC11160616 DOI: 10.1101/2024.05.27.596058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
Lipid transfer through membrane contact has been implicated to support vesicular transport, but a mechanistic understanding of this process remains to be achieved. Here, examining Coat Protein I (COPI) transport, we find that phosphatidylcholine (PC) with short acyl chains (sPC), which is needed to support COPI vesicle fission, is delivered through membrane contact from the endoplasmic reticulum (ER) to the Golgi complex at sites of COPI vesicle formation. Phosphatidylinositol transfer protein beta (PITPβ) plays a central role in this delivery by not only catalyzing PC transfer, but also forming membrane contact. By combining cell-based studies with reconstitution approaches, we achieve spatial and temporal detail in explaining how sPC delivery occurs. Our findings advance the mechanistic understanding of how membrane contact is needed for vesicular transport in a model pathway and shed new insights into how PITPβ acts.
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Affiliation(s)
- Kunyou Park
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Gyeongbuk 37673, Republic of Korea
- Division of Rheumatology, Inflammation and Immunity, Brigham and Women’s Hospital, and Department of Medicine, Harvard Medical School, Boston, MA 02115, USA
| | - Sungeun Ju
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Gyeongbuk 37673, Republic of Korea
| | - Hyewon Choi
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Gyeongbuk 37673, Republic of Korea
| | - Peng Gao
- School of Life Sciences, State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Geul Bang
- Research Center for Bioconvergence Analysis, Korea Basic Science Institute, Cheongju, Republic of Korea
| | - Jung Hoon Choi
- Department of Bio-Chemical Analysis, Korea Basic Science Institute, Cheongju, Republic of Korea
| | - Jiwon Jang
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Gyeongbuk 37673, Republic of Korea
| | - Andrew J. Morris
- University of Arkansas for Medical Sciences and Central Arkansas Veterans Affairs Healthcare System, Little Rock, AR 72205, USA
| | - Byung-Ho Kang
- School of Life Sciences, State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Victor W. Hsu
- Division of Rheumatology, Inflammation and Immunity, Brigham and Women’s Hospital, and Department of Medicine, Harvard Medical School, Boston, MA 02115, USA
| | - Seung-Yeol Park
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Gyeongbuk 37673, Republic of Korea
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3
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Petsana M, Roumia AF, Bagos PG, Boleti H, Braliou GG. In Silico Identification and Analysis of Proteins Containing the Phox Homology Phosphoinositide-Binding Domain in Kinetoplastea Protists: Evolutionary Conservation and Uniqueness of Phox-Homology-Domain-Containing Protein Architectures. Int J Mol Sci 2023; 24:11521. [PMID: 37511280 PMCID: PMC10380299 DOI: 10.3390/ijms241411521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 06/27/2023] [Accepted: 07/05/2023] [Indexed: 07/30/2023] Open
Abstract
Kinetoplastea are free living and parasitic protists with unique features among Eukaryota. Pathogenic Kinetoplastea parasites (i.e., Trypanosoma and Leishmania spp.) undergo several developmental transitions essential for survival in their hosts. These transitions require membrane and cytoskeleton reorganizations that involve phosphoinositides (PIs). Phospholipids like PIs are key regulators of vital functions in all eukaryotes including signal transduction, protein transport and sorting, membrane trafficking, and cytoskeleton and membrane remodeling. A large repertoire of PI-metabolizing enzymes and PI-binding proteins/effectors carrying distinct PI-binding modules like the PX (phox homology) module could play significant roles in the life and virulence of pathogenic Kinetoplastea. The aim of this study was to retrieve the entire spectrum of Kinetoplastea protein sequences containing the PX module (PX-proteins), predict their structures, and identify in them evolutionary conserved and unique traits. Using a large array of bioinformatics tools, protein IDs from two searches (based on PFam's pHMM for PX domain (PF00787)) were combined, aligned, and utilized for the construction of a new Kinetoplastea_PX pHMM. This three-step search retrieved 170 PX-protein sequences. Structural domain configuration analysis identified PX, Pkinase, Lipocalin_5, and Vps5/BAR3-WASP domains and clustered them into five distinct subfamilies. Phylogenetic tree and domain architecture analysis showed that some domain architectures exist in proteomes of all Kinetoplastea spp., while others are genus-specific. Finally, amino acid conservation logos of the Kinetoplastea spp. and Homo sapiens PX domains revealed high evolutionary conservation in residues forming the critical structural motifs for PtdIns3P recognition. This study highlights the PX-Pkinase domain architecture as unique within Trypanosoma spp. and forms the basis for a targeted functional analysis of Kinetoplastea PX-proteins as putative targets for a rational design of anti-parasitic drugs.
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Affiliation(s)
- Marina Petsana
- Department of Computer Science and Biomedical Informatics, University of Thessaly, 2-4 Papasiopoulou Str., 35131 Lamia, Greece
- Intracellular Parasitism Laboratory, Department of Microbiology, Hellenic Pasteur Institute, 11521 Athens, Greece
| | - Ahmed F Roumia
- Department of Computer Science and Biomedical Informatics, University of Thessaly, 2-4 Papasiopoulou Str., 35131 Lamia, Greece
- Department of Agricultural Biochemistry, Faculty of Agriculture, Menoufia University, Shibin El-Kom 32514, Egypt
| | - Pantelis G Bagos
- Department of Computer Science and Biomedical Informatics, University of Thessaly, 2-4 Papasiopoulou Str., 35131 Lamia, Greece
| | - Haralabia Boleti
- Intracellular Parasitism Laboratory, Department of Microbiology, Hellenic Pasteur Institute, 11521 Athens, Greece
| | - Georgia G Braliou
- Department of Computer Science and Biomedical Informatics, University of Thessaly, 2-4 Papasiopoulou Str., 35131 Lamia, Greece
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Montag K, Ivanov R, Bauer P. Role of SEC14-like phosphatidylinositol transfer proteins in membrane identity and dynamics. FRONTIERS IN PLANT SCIENCE 2023; 14:1181031. [PMID: 37255567 PMCID: PMC10225987 DOI: 10.3389/fpls.2023.1181031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 04/05/2023] [Indexed: 06/01/2023]
Abstract
Membrane identity and dynamic processes, that act at membrane sites, provide important cues for regulating transport, signal transduction and communication across membranes. There are still numerous open questions as to how membrane identity changes and the dynamic processes acting at the surface of membranes are regulated in diverse eukaryotes in particular plants and which roles are being played by protein interaction complexes composed of peripheral and integral membrane proteins. One class of peripheral membrane proteins conserved across eukaryotes comprises the SEC14-like phosphatidylinositol transfer proteins (SEC14L-PITPs). These proteins share a SEC14 domain that contributes to membrane identity and fulfills regulatory functions in membrane trafficking by its ability to sense, bind, transport and exchange lipophilic substances between membranes, such as phosphoinositides and diverse other lipophilic substances. SEC14L-PITPs can occur as single-domain SEC14-only proteins in all investigated organisms or with a modular domain structure as multi-domain proteins in animals and streptophytes (comprising charales and land plants). Here, we present an overview on the functional roles of SEC14L-PITPs, with a special focus on the multi-domain SEC14L-PITPs of the SEC14-nodulin and SEC14-GOLD group (PATELLINs, PATLs in plants). This indicates that SEC14L-PITPs play diverse roles from membrane trafficking to organism fitness in plants. We concentrate on the structure of SEC14L-PITPs, their ability to not only bind phospholipids but also other lipophilic ligands, and their ability to regulate complex cellular responses through interacting with proteins at membrane sites.
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Affiliation(s)
- Karolin Montag
- Institute of Botany, Heinrich Heine University, Düsseldorf, Germany
| | - Rumen Ivanov
- Institute of Botany, Heinrich Heine University, Düsseldorf, Germany
| | - Petra Bauer
- Institute of Botany, Heinrich Heine University, Düsseldorf, Germany
- Center of Excellence on Plant Sciences (CEPLAS), Germany
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5
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A Perspective on the Link between Mitochondria-Associated Membranes (MAMs) and Lipid Droplets Metabolism in Neurodegenerative Diseases. BIOLOGY 2023; 12:biology12030414. [PMID: 36979106 PMCID: PMC10045954 DOI: 10.3390/biology12030414] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 03/03/2023] [Accepted: 03/06/2023] [Indexed: 03/11/2023]
Abstract
Mitochondria interact with the endoplasmic reticulum (ER) through contacts called mitochondria-associated membranes (MAMs), which control several processes, such as the ER stress response, mitochondrial and ER dynamics, inflammation, apoptosis, and autophagy. MAMs represent an important platform for transport of non-vesicular phospholipids and cholesterol. Therefore, this region is highly enriched in proteins involved in lipid metabolism, including the enzymes that catalyze esterification of cholesterol into cholesteryl esters (CE) and synthesis of triacylglycerols (TAG) from fatty acids (FAs), which are then stored in lipid droplets (LDs). LDs, through contact with other organelles, prevent the toxic consequences of accumulation of unesterified (free) lipids, including lipotoxicity and oxidative stress, and serve as lipid reservoirs that can be used under multiple metabolic and physiological conditions. The LDs break down by autophagy releases of stored lipids for energy production and synthesis of membrane components and other macromolecules. Pathological lipid deposition and autophagy disruption have both been reported to occur in several neurodegenerative diseases, supporting that lipid metabolism alterations are major players in neurodegeneration. In this review, we discuss the current understanding of MAMs structure and function, focusing on their roles in lipid metabolism and the importance of autophagy in LDs metabolism, as well as the changes that occur in neurogenerative diseases.
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6
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Krishnan H, Basak B, Nath VR, Mishra S, Raghu P. Structural organization of RDGB (retinal degeneration B), a multi-domain lipid transfer protein: a molecular modelling and simulation based approach. J Biomol Struct Dyn 2023; 41:13368-13382. [PMID: 36803287 DOI: 10.1080/07391102.2023.2179545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Accepted: 01/20/2023] [Indexed: 02/22/2023]
Abstract
Lipid transfer proteins (LTPs) that shuttle lipids at membrane contact sites (MCS) play an important role in maintaining cellular homeostasis. One such important LTP is the Retinal Degeneration B (RDGB) protein. RDGB is localized at the MCS formed between the endoplasmic reticulum (ER) and the apical plasma membrane (PM) in Drosophila photoreceptors where it transfers phosphatidylinositol (PI) during G-protein coupled phospholipase C signalling. Previously, the C-terminal domains of RDGB have been shown to be essential for its function and accurate localization. In this study, using in-silico integrative modelling we predict the structure of entire RDGB protein in complex with the ER membrane protein VAP. The structure of RDGB has then been used to decipher the structural features of the protein important for its orientation at the contact site. Using this structure, we identify two lysine residues in the C-terminal helix of the LNS2 domain important for interaction with the PM. Using molecular docking, we also identify an unstructured region USR1, immediately c-terminal to the PITP domain that is important for the interaction of RDGB with VAP. Overall the 10.06 nm length of the predicted RDGB-VAP complex spans the distance between the PM and ER and is consistent with the cytoplasmic gap between the ER and PM measured by transmission electron microscopy in photoreceptors. Overall our model explains the topology of the RDGB-VAP complex at this ER-PM contact site and paves the way for analysis of lipid transfer function in this setting.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Harini Krishnan
- National Centre for Biological Sciences, TIFR-GKVK Campus, Bengaluru, India
| | - Bishal Basak
- National Centre for Biological Sciences, TIFR-GKVK Campus, Bengaluru, India
| | - Vaisaly R Nath
- National Centre for Biological Sciences, TIFR-GKVK Campus, Bengaluru, India
| | - Shirish Mishra
- National Centre for Biological Sciences, TIFR-GKVK Campus, Bengaluru, India
| | - Padinjat Raghu
- National Centre for Biological Sciences, TIFR-GKVK Campus, Bengaluru, India
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7
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Gasdermin D maintains bone mass by rewiring the endo-lysosomal pathway of osteoclastic bone resorption. Dev Cell 2022; 57:2365-2380.e8. [DOI: 10.1016/j.devcel.2022.09.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 07/03/2022] [Accepted: 09/23/2022] [Indexed: 11/03/2022]
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8
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Barneda D, Janardan V, Niewczas I, Collins DM, Cosulich S, Clark J, Stephens LR, Hawkins PT. Acyl chain selection couples the consumption and synthesis of phosphoinositides. EMBO J 2022; 41:e110038. [PMID: 35771169 PMCID: PMC9475507 DOI: 10.15252/embj.2021110038] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 05/11/2022] [Accepted: 05/12/2022] [Indexed: 12/12/2022] Open
Abstract
Phosphoinositides (PIPn) in mammalian tissues are enriched in the stearoyl/arachidonoyl acyl chain species ("C38:4"), but its functional significance is unclear. We have used metabolic tracers (isotopologues of inositol, glucose and water) to study PIPn synthesis in cell lines in which this enrichment is preserved to differing relative extents. We show that PIs synthesised from glucose are initially enriched in shorter/more saturated acyl chains, but then rapidly remodelled towards the C38:4 species. PIs are also synthesised by a distinct 're-cycling pathway', which utilises existing precursors and exhibits substantial selectivity for the synthesis of C38:4-PA and -PI. This re-cycling pathway is rapidly stimulated during receptor activation of phospholipase-C, both allowing the retention of the C38:4 backbone and the close coupling of PIPn consumption to its resynthesis, thus maintaining pool sizes. These results suggest that one property of the specific acyl chain composition of PIPn is that of a molecular code, to facilitate 'metabolic channelling' from PIP2 to PI via pools of intermediates (DG, PA and CDP-DG) common to other lipid metabolic pathways.
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Affiliation(s)
- David Barneda
- Signalling Programme, Babraham Institute, Cambridge, UK.,Projects, Oncology R&D, AstraZeneca, Cambridge, UK
| | - Vishnu Janardan
- Cellular Organization and Signalling, National Centre for Biological Sciences, Bangalore, India
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9
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Krawczyk HE, Sun S, Doner NM, Yan Q, Lim MSS, Scholz P, Niemeyer PW, Schmitt K, Valerius O, Pleskot R, Hillmer S, Braus GH, Wiermer M, Mullen RT, Ischebeck T. SEED LIPID DROPLET PROTEIN1, SEED LIPID DROPLET PROTEIN2, and LIPID DROPLET PLASMA MEMBRANE ADAPTOR mediate lipid droplet-plasma membrane tethering. THE PLANT CELL 2022; 34:2424-2448. [PMID: 35348751 PMCID: PMC9134073 DOI: 10.1093/plcell/koac095] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Accepted: 02/14/2022] [Indexed: 05/27/2023]
Abstract
Membrane contact sites (MCSs) are interorganellar connections that allow for the direct exchange of molecules, such as lipids or Ca2+ between organelles, but can also serve to tether organelles at specific locations within cells. Here, we identified and characterized three proteins of Arabidopsis thaliana that form a lipid droplet (LD)-plasma membrane (PM) tethering complex in plant cells, namely LD-localized SEED LD PROTEIN (SLDP) 1 and SLDP2 and PM-localized LD-PLASMA MEMBRANE ADAPTOR (LIPA). Using proteomics and different protein-protein interaction assays, we show that both SLDPs associate with LIPA. Disruption of either SLDP1 and SLDP2 expression, or that of LIPA, leads to an aberrant clustering of LDs in Arabidopsis seedlings. Ectopic co-expression of one of the SLDPs with LIPA is sufficient to reconstitute LD-PM tethering in Nicotiana tabacum pollen tubes, a cell type characterized by dynamically moving LDs in the cytosolic streaming. Furthermore, confocal laser scanning microscopy revealed both SLDP2.1 and LIPA to be enriched at LD-PM contact sites in seedlings. These and other results suggest that SLDP and LIPA interact to form a tethering complex that anchors a subset of LDs to the PM during post-germinative seedling growth in Arabidopsis.
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Affiliation(s)
- Hannah Elisa Krawczyk
- Albrecht-von-Haller-Institute for Plant Sciences and Göttingen Center for Molecular Biosciences (GZMB), Department of Plant Biochemistry, University of Göttingen, Göttingen, Germany
| | - Siqi Sun
- Albrecht-von-Haller-Institute for Plant Sciences and Göttingen Center for Molecular Biosciences (GZMB), Department of Plant Biochemistry, University of Göttingen, Göttingen, Germany
| | - Nathan M Doner
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Qiqi Yan
- Albrecht-von-Haller-Institute for Plant Sciences and Göttingen Center for Molecular Biosciences (GZMB), Molecular Biology of Plant-Microbe Interactions Research Group, University of Göttingen, Göttingen, Germany
| | - Magdiel Sheng Satha Lim
- Albrecht-von-Haller-Institute for Plant Sciences and Göttingen Center for Molecular Biosciences (GZMB), Department of Plant Biochemistry, University of Göttingen, Göttingen, Germany
| | - Patricia Scholz
- Albrecht-von-Haller-Institute for Plant Sciences and Göttingen Center for Molecular Biosciences (GZMB), Department of Plant Biochemistry, University of Göttingen, Göttingen, Germany
| | - Philipp William Niemeyer
- Albrecht-von-Haller-Institute for Plant Sciences and Göttingen Center for Molecular Biosciences (GZMB), Department of Plant Biochemistry, University of Göttingen, Göttingen, Germany
| | - Kerstin Schmitt
- Institute for Microbiology and Genetics and Göttingen Center for Molecular Biosciences (GZMB) and Service Unit LCMS Protein Analytics, Department for Molecular Microbiology and Genetics, University of Göttingen, Göttingen, Germany
- Göttingen Center for Molecular Biosciences (GZMB), University of Göttingen, Göttingen, Germany
| | - Oliver Valerius
- Institute for Microbiology and Genetics and Göttingen Center for Molecular Biosciences (GZMB) and Service Unit LCMS Protein Analytics, Department for Molecular Microbiology and Genetics, University of Göttingen, Göttingen, Germany
- Göttingen Center for Molecular Biosciences (GZMB), University of Göttingen, Göttingen, Germany
| | - Roman Pleskot
- Institute of Experimental Botany of the Czech Academy of Sciences, Prague, Czech Republic
| | - Stefan Hillmer
- Electron Microscopy Core Facility, Heidelberg University, Heidelberg, Germany
| | - Gerhard H Braus
- Institute for Microbiology and Genetics and Göttingen Center for Molecular Biosciences (GZMB) and Service Unit LCMS Protein Analytics, Department for Molecular Microbiology and Genetics, University of Göttingen, Göttingen, Germany
- Göttingen Center for Molecular Biosciences (GZMB), University of Göttingen, Göttingen, Germany
| | - Marcel Wiermer
- Albrecht-von-Haller-Institute for Plant Sciences and Göttingen Center for Molecular Biosciences (GZMB), Molecular Biology of Plant-Microbe Interactions Research Group, University of Göttingen, Göttingen, Germany
- Göttingen Center for Molecular Biosciences (GZMB), University of Göttingen, Göttingen, Germany
| | - Robert T Mullen
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1G 2W1, Canada
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10
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Qian T, Li C, Liu F, Xu K, Wan C, Liu Y, Yu H. Arabidopsis synaptotagmin 1 mediates lipid transport in a lipid composition-dependent manner. Traffic 2022; 23:346-356. [PMID: 35451158 DOI: 10.1111/tra.12844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 04/11/2022] [Accepted: 04/15/2022] [Indexed: 11/29/2022]
Abstract
The endoplasmic reticulum (ER) - plasma membrane (PM) contact sites (EPCSs) are structurally conserved in eukaryotes. The Arabidopsis ER-anchored synaptotagmin 1 (SYT1), enriched in EPCSs, plays a critical role in plant abiotic stress tolerance. It has become clear that SYT1 interacts with PM to mediate ER-PM connectivity. However, whether SYT1 performs additional functions at EPCSs remains unknown. Here, we reported that SYT1 efficiently transfers phospholipids between membranes. The lipid transfer activity of SYT1 is highly dependent on PI(4,5)P2 , a signal lipid accumulated at the PM under abiotic stress. Mechanically, while SYT1 transfers lipids fundamentally through the synaptotagmin-like mitochondrial-lipid-binding protein (SMP) domain, the efficient lipid transport requires the C2A domain-mediated membrane tethering. Interestingly, we observed that Ca2+ could stimulate SYT1-mediated lipid transport. In addition to PI(4,5)P2 , the Ca2+ activation requires the phosphatidylserine, another negatively charged lipid on the opposed membrane. Together, our studies identified Arabidopsis SYT1 as a lipid transfer protein at EPCSs and demonstrated it takes conserved as well as divergent mechanisms with other extend-synaptotagmins. The critical role of lipid composition and Ca2+ reveals SYT1-mediated lipid transport is highly regulated by signals in response to abiotic stresses.
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Affiliation(s)
- Tiantian Qian
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Chenlu Li
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Furong Liu
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Kai Xu
- Jiangsu Key Laboratory for Microbes and Functional Genomics, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Chun Wan
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, CO, USA
| | - Yinghui Liu
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Haijia Yu
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
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11
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Graph-theoretic constraints on vesicle traffic networks. J Biosci 2022. [DOI: 10.1007/s12038-021-00252-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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12
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De Camilli P. How a first research experience had an impact on my scientific journey. Mol Biol Cell 2021; 32:ae1. [PMID: 34735266 PMCID: PMC8694089 DOI: 10.1091/mbc.e21-08-0397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
As I look back to my scientific trajectory on the occasion of being the recipient of the E. B. Wilson Medal of the American Society for Cell Biology, I realize how much an early scientific experience had an impact on my research many years later. The major influence that the first scientific encounters can have in defining a scientist’s path makes the choice of the training environment so important for a future career.
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Affiliation(s)
- Pietro De Camilli
- Departments of Neuroscience and Cell Biology, Howard Hughes Medical Institute, Program in Cellular Neuroscience, Neurodegeneration and Repair, Kavli Institute for Neuroscience, Yale School of Medicine, New Haven, CT 06510
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13
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Ikhlef S, Lipp NF, Delfosse V, Fuggetta N, Bourguet W, Magdeleine M, Drin G. Functional analyses of phosphatidylserine/PI(4)P exchangers with diverse lipid species and membrane contexts reveal unanticipated rules on lipid transfer. BMC Biol 2021; 19:248. [PMID: 34801011 PMCID: PMC8606082 DOI: 10.1186/s12915-021-01183-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 11/04/2021] [Indexed: 11/14/2022] Open
Abstract
Background Lipid species are accurately distributed in the eukaryotic cell so that organelle and plasma membranes have an adequate lipid composition to support numerous cellular functions. In the plasma membrane, a precise regulation of the level of lipids such as phosphatidylserine, PI(4)P, and PI(4,5)P2, is critical for maintaining the signaling competence of the cell. Several lipid transfer proteins of the ORP/Osh family contribute to this fine-tuning by delivering PS, synthesized in the endoplasmic reticulum, to the plasma membrane in exchange for PI(4)P. To get insights into the role of these PS/PI(4)P exchangers in regulating plasma membrane features, we question how they selectively recognize and transfer lipid ligands with different acyl chains, whether these proteins exchange PS exclusively for PI(4)P or additionally for PI(4,5)P2, and how sterol abundance in the plasma membrane impacts their activity. Results We measured in vitro how the yeast Osh6p and human ORP8 transported PS and PI(4)P subspecies of diverse length and unsaturation degree between membranes by fluorescence-based assays. We established that the exchange activity of Osh6p and ORP8 strongly depends on whether these ligands are saturated or not, and is high with representative cellular PS and PI(4)P subspecies. Unexpectedly, we found that the speed at which these proteins individually transfer lipid ligands between membranes is inversely related to their affinity for them and that high-affinity ligands must be exchanged to be transferred more rapidly. Next we determined that Osh6p and ORP8 cannot use PI(4,5)P2 for exchange processes, because it is a low-affinity ligand, and do not transfer more PS into sterol-rich membranes. Conclusions Our study provides new insights into PS/PI(4)P exchangers by indicating the degree to which they can regulate the acyl chain composition of the PM, and how they control PM phosphoinositide levels. Moreover, we establish general rules on how the activity of lipid transfer proteins relates to their affinity for ligands. Supplementary Information The online version contains supplementary material available at 10.1186/s12915-021-01183-1.
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Affiliation(s)
- Souade Ikhlef
- Université Côte d'Azur, Centre National de la Recherche Scientifique, Institut de Pharmacologie Moléculaire et Cellulaire, 660 route des lucioles, 06560, Valbonne, France
| | - Nicolas-Frédéric Lipp
- Université Côte d'Azur, Centre National de la Recherche Scientifique, Institut de Pharmacologie Moléculaire et Cellulaire, 660 route des lucioles, 06560, Valbonne, France.,Current position: Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA, USA
| | - Vanessa Delfosse
- Centre de Biologie Structurale, INSERM, CNRS, Université de Montpellier, Montpellier, France
| | - Nicolas Fuggetta
- Université Côte d'Azur, Centre National de la Recherche Scientifique, Institut de Pharmacologie Moléculaire et Cellulaire, 660 route des lucioles, 06560, Valbonne, France
| | - William Bourguet
- Centre de Biologie Structurale, INSERM, CNRS, Université de Montpellier, Montpellier, France
| | - Maud Magdeleine
- Université Côte d'Azur, Centre National de la Recherche Scientifique, Institut de Pharmacologie Moléculaire et Cellulaire, 660 route des lucioles, 06560, Valbonne, France
| | - Guillaume Drin
- Université Côte d'Azur, Centre National de la Recherche Scientifique, Institut de Pharmacologie Moléculaire et Cellulaire, 660 route des lucioles, 06560, Valbonne, France.
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14
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Cockcroft S. Mammalian lipids: structure, synthesis and function. Essays Biochem 2021; 65:813-845. [PMID: 34415021 PMCID: PMC8578989 DOI: 10.1042/ebc20200067] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 07/05/2021] [Accepted: 08/04/2021] [Indexed: 12/13/2022]
Abstract
Lipids are essential constituents of cellular membranes. Once regarded merely as structural components, lipids have taken centre stage with the discovery of their roles in cell signalling and in the generation of bioactive metabolites. Lipids regulate many physiological functions of cells and alterations in membrane lipid metabolism are associated with major diseases including cancer, Type II diabetes, cardiovascular disease and immune disorders. Understanding lipid diversity, their synthesis and metabolism to generate signalling molecules will provide insight into the fundamental function of the cell. This review summarises the biosynthesis of the lipids of the mammalian cell; phospholipids, sphingolipids and cholesterol and how lipid diversity is achieved. The fatty acids (FAs) are the main building blocks of lipids and contribute to the diversity. Lipid synthesis is intimately connected to their transport within cells; the contribution by proteins that transport lipids, lipid transport proteins will be described. Cellular lipids are metabolised by phospholipases, lipid kinases and phosphatases to make new bioactive metabolites. These transient bioactive metabolites allow cells to respond to the external environment to maintain cellular health. The function of individual metabolites is also highlighted. Bioactive metabolites can be second messengers, or released to the external medium to regulate other cells. Alternatively, bioactive lipids also provide a platform for reversible recruitment of proteins to membranes using their lipid-binding domains. The wide range of physiological processes in which a specific involvement of lipids has been identified explains the need for lipid diversity present in mammalian cells.
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Affiliation(s)
- Shamshad Cockcroft
- Department of Neuroscience, Physiology and Pharmacology, Division of Biosciences, University College London, 21 University Street, London WC1E 6JJ, U.K
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15
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Raghu P, Basak B, Krishnan H. Emerging perspectives on multidomain phosphatidylinositol transfer proteins. Biochim Biophys Acta Mol Cell Biol Lipids 2021; 1866:158984. [PMID: 34098114 PMCID: PMC7611342 DOI: 10.1016/j.bbalip.2021.158984] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Revised: 05/23/2021] [Accepted: 05/25/2021] [Indexed: 12/09/2022]
Abstract
The phosphatidylinositol transfer protein domain (PITPd) is an evolutionarily conserved protein that is able to transfer phosphatidylinositol between membranes in vitro and in vivo. However some animal genomes also include genes that encode proteins where the PITPd is found in cis with a number of additional domains and recent large scale genome sequencing efforts indicate that this type of multidomain architecture is widespread in the animal kingdom. In Drosophila photoreceptors, the multidomain phosphatidylinositol transfer protein RDGB is required to regulate phosphoinositide turnover during G-protein activated phospholipase C signalling. Recent studies in flies and mammalian cell culture models have begun to elucidate functions for the non-PITPd of RDGB and its vertebrate orthologs. We review emerging evidence on the genomics, functional and cell biological perspectives of these multi-domain PITPd containing proteins.
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Affiliation(s)
- Padinjat Raghu
- National Centre for Biological Sciences, TIFR-GKVK Campus, Bellary Road, Bengaluru 560065, India.
| | - Bishal Basak
- National Centre for Biological Sciences, TIFR-GKVK Campus, Bellary Road, Bengaluru 560065, India
| | - Harini Krishnan
- National Centre for Biological Sciences, TIFR-GKVK Campus, Bellary Road, Bengaluru 560065, India
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16
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Girotti AW, Korytowski W. Pathophysiological potential of lipid hydroperoxide intermembrane translocation: Cholesterol hydroperoxide translocation as a special case. Redox Biol 2021; 46:102096. [PMID: 34418596 PMCID: PMC8379493 DOI: 10.1016/j.redox.2021.102096] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 08/04/2021] [Accepted: 08/05/2021] [Indexed: 10/29/2022] Open
Abstract
Peroxidation of unsaturated phospholipids, glycolipids, and cholesterol in biological membranes under oxidative stress conditions can underlie a variety of pathological conditions, including atherogenesis, neurodegeneration, and carcinogenesis. Lipid hydroperoxides (LOOHs) are key intermediates in the peroxidative process. Nascent LOOHs may either undergo one-electron reduction to exacerbate membrane damage/dysfunction or two-electron reduction to attenuate this. Another possibility is LOOH translocation to an acceptor site, followed by either of these competing reductions. Cholesterol (Ch)-derived hydroperoxides (ChOOHs) have several special features that will be highlighted in this review. In addition to being susceptible to one-electron vs. two-electron reduction, ChOOHs can translocate from a membrane of origin to another membrane, where such turnover may ensue. Intracellular StAR family proteins have been shown to deliver not only Ch to mitochondria, but also ChOOHs. StAR-mediated transfer of free radical-generated 7-hydroperoxycholesterol (7-OOH) results in impairment of (a) Ch utilization in steroidogenic cells, and (b) anti-atherogenic reverse Ch transport in vascular macrophages. This is the first known example of how a peroxide derivative can be recognized by a natural lipid trafficking pathway with deleterious consequences. For each example above, we will discuss the underlying mechanism of oxidative damage/dysfunction, and how this might be mitigated by antioxidant intervention.
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Affiliation(s)
- Albert W Girotti
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI, USA.
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17
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Jiang C, Huang X, Yao J, Yu L, Wei F, Yang A. The role of membrane contact sites at the bacteria-host interface. Crit Rev Microbiol 2021; 48:270-282. [PMID: 34403642 DOI: 10.1080/1040841x.2021.1961678] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Membrane contact sites (MCSs) refer to the areas of close proximity between heterologous membranes. A growing body of evidence indicates that MCSs are involved in important cellular functions, such as cellular material transfer, organelle biogenesis, and cell growth. Importantly, the study of MCSs at the bacteria-host interface is an emerging popular research topic. Intracellular bacterial pathogens have evolved a variety of fascinating strategies to interfere with MCSs by injecting effectors into infected host cells. Bacteria-containing vacuoles establish direct physical contact with organelles within the host, ensuring vacuolar membrane integrity and energy supply from host organelles and protecting the vacuoles from the host endocytic pathway and lysosomal degradation. An increasing number of bacterial effectors from various bacterial pathogens hijack components of host MCSs to form the vacuole-organelle MCSs for material exchange. MCS-related events have been identified as new mechanisms of microbial pathogenesis to greatly improve bacterial survival and replication within host cells. In this review, we will discuss the recent advances in MCSs at the bacteria-host interface, focussing on the roles of MCSs mediated by bacterial effectors in microbial pathogenesis.
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Affiliation(s)
- Chen Jiang
- School of Life Sciences, Chongqing University, Chongqing, China
| | - Xue Huang
- School of Life Sciences, Chongqing University, Chongqing, China
| | - Jia Yao
- School of Life Sciences, Chongqing University, Chongqing, China
| | - Lihua Yu
- School of Life Sciences, Chongqing University, Chongqing, China
| | - Fujing Wei
- School of Life Sciences, Chongqing University, Chongqing, China
| | - Aimin Yang
- School of Life Sciences, Chongqing University, Chongqing, China
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18
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Borgese N, Iacomino N, Colombo SF, Navone F. The Link between VAPB Loss of Function and Amyotrophic Lateral Sclerosis. Cells 2021; 10:1865. [PMID: 34440634 PMCID: PMC8392409 DOI: 10.3390/cells10081865] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 07/16/2021] [Accepted: 07/16/2021] [Indexed: 02/06/2023] Open
Abstract
The VAP proteins are integral adaptor proteins of the endoplasmic reticulum (ER) membrane that recruit a myriad of interacting partners to the ER surface. Through these interactions, the VAPs mediate a large number of processes, notably the generation of membrane contact sites between the ER and essentially all other cellular membranes. In 2004, it was discovered that a mutation (p.P56S) in the VAPB paralogue causes a rare form of dominantly inherited familial amyotrophic lateral sclerosis (ALS8). The mutant protein is aggregation-prone, non-functional and unstable, and its expression from a single allele appears to be insufficient to support toxic gain-of-function effects within motor neurons. Instead, loss-of-function of the single wild-type allele is required for pathological effects, and VAPB haploinsufficiency may be the main driver of the disease. In this article, we review the studies on the effects of VAPB deficit in cellular and animal models. Several basic cell physiological processes are affected by downregulation or complete depletion of VAPB, impinging on phosphoinositide homeostasis, Ca2+ signalling, ion transport, neurite extension, and ER stress. In the future, the distinction between the roles of the two VAP paralogues (A and B), as well as studies on motor neurons generated from induced pluripotent stem cells (iPSC) of ALS8 patients will further elucidate the pathogenic basis of p.P56S familial ALS, as well as of other more common forms of the disease.
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Affiliation(s)
- Nica Borgese
- CNR Institute of Neuroscience, Via Follereau 3, Bldg U28, 20854 Vedano al Lambro, Italy; (N.I.); (S.F.C.)
| | | | | | - Francesca Navone
- CNR Institute of Neuroscience, Via Follereau 3, Bldg U28, 20854 Vedano al Lambro, Italy; (N.I.); (S.F.C.)
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19
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Rathod J, Yen HC, Liang B, Tseng YY, Chen CS, Wu WS. YPIBP: A repository for phosphoinositide-binding proteins in yeast. Comput Struct Biotechnol J 2021; 19:3692-3707. [PMID: 34285772 PMCID: PMC8261538 DOI: 10.1016/j.csbj.2021.06.035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 06/08/2021] [Accepted: 06/22/2021] [Indexed: 11/25/2022] Open
Abstract
Phosphoinositides (PIs) are a family of eight lipids consisting of phosphatidylinositol (PtdIns) and its seven phosphorylated forms. PIs have important regulatory functions in the cell including lipid signaling, protein transport, and membrane trafficking. Yeast has been recognized as a eukaryotic model system to study lipid-protein interactions. Hundreds of yeast PI-binding proteins have been identified, but this research knowledge remains scattered. Besides, the complete PI-binding spectrum and potential PI-binding domains have not been interlinked. No comprehensive databases are available to support the lipid-protein interaction research on phosphoinositides. Here we constructed the first knowledgebase of Yeast Phosphoinositide-Binding Proteins (YPIBP), a repository consisting of 679 PI-binding proteins collected from high-throughput proteome-array and lipid-array studies, QuickGO, and a rigorous literature mining. The YPIBP also contains protein domain information in categories of lipid-binding domains, lipid-related domains and other domains. The YPIBP provides search and browse modes along with two enrichment analyses (PI-binding enrichment analysis and domain enrichment analysis). An interactive visualization is given to summarize the PI-domain-protein interactome. Finally, three case studies were given to demonstrate the utility of YPIBP. The YPIBP knowledgebase consolidates the present knowledge and provides new insights of the PI-binding proteins by bringing comprehensive and in-depth interaction network of the PI-binding proteins. YPIBP is available at http://cosbi7.ee.ncku.edu.tw/YPIBP/.
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Key Words
- ANTH, AP180 N-terminal Homology
- BAR, Bin-Amphiphysin-Rvs
- CAFA, Critical Assessment of Functional Annotation
- CRAL-TRIO, cellular retinaldehyde-binding protein (CRALBP) and TRIO guanine exchange factor
- Cvt, Cytoplasm-to-vacuole targeting
- ENTH, Epsin N-terminal Homology
- FDR, False Discovery Rate
- FYVE, Fab 1 (yeast orthologue of PIKfyve), YOTB, Vac 1 (vesicle transport protein), and EEA1
- GO, Gene Ontology
- ITC, Isothermal Titration Calorimetry
- LBD, Lipid-Binding Domain
- LMPD, LIPID MAPS Proteome Database
- LMSD, LIPID MAPS Structure Database
- LRD, Lipid-Related Domain
- Lipid-binding domain
- OMIM, Online Mendelian Inheritance in Man
- OSBP, Oxysterol-Binding Protein
- PH, Pleckstrin Homology
- PI(3,4)P2, phosphatidylinositol-3,4-bisphosphate
- PI(3,4,5)P3, phosphatidylinositol-3,4,5-trisphosphate
- PI(3,5)P2, phosphatidylinositol-3,5-bisphosphate
- PI(4,5)P2, phosphatidylinositol-4,5-bisphosphate
- PI-binding protein
- PI3P, phosphatidylinositol-3-phosphate
- PI4P, phosphatidylinositol-4-phosphate
- PI5P, phosphatidylinositol-5-phosphate
- PIs, Phosphoinositides
- PMID, PubMed ID
- PX, Phox Homology
- Phosphatidylinositol (PtdIns)
- Phosphoinositides (PIs)
- PtdIns, Phosphatidylinositol
- QCM, Quartz Crystal Microbalance
- S. cerevisiae
- SNX, Sorting Nexin
- SPR, Surface Plasmon Resonance
- YPIBP, Yeast Phosphoinositide-Binding Proteins
- Yeast
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Affiliation(s)
- Jagat Rathod
- Department of Earth Sciences, College of Sciences, National Cheng Kung University, Tainan 701, Taiwan
| | - Han-Chen Yen
- Department of Electrical Engineering, College of Electrical Engineering and Computer Science, National Cheng Kung University, Tainan 701, Taiwan
| | - Biqing Liang
- Department of Earth Sciences, College of Sciences, National Cheng Kung University, Tainan 701, Taiwan
| | - Yan-Yuan Tseng
- Center for Molecular Medicine and Genetics, Wayne State University, School of Medicine, Detroit, MI 48201, USA
| | - Chien-Sheng Chen
- Department of Food Safety/Hygiene and Risk Management, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan
| | - Wei-Sheng Wu
- Department of Electrical Engineering, College of Electrical Engineering and Computer Science, National Cheng Kung University, Tainan 701, Taiwan
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20
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Holič R, Šťastný D, Griač P. Sec14 family of lipid transfer proteins in yeasts. Biochim Biophys Acta Mol Cell Biol Lipids 2021; 1866:158990. [PMID: 34118432 DOI: 10.1016/j.bbalip.2021.158990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 05/31/2021] [Accepted: 06/02/2021] [Indexed: 11/25/2022]
Abstract
The hydrophobicity of lipids prevents their free movement across the cytoplasm. To achieve highly heterogeneous and precisely regulated lipid distribution in different cellular membranes, lipids are transported by lipid transfer proteins (LTPs) in addition to their transport by vesicles. Sec14 family is one of the most extensively studied groups of LTPs. Here we provide an overview of Sec14 family of LTPs in the most studied yeast Saccharomyces cerevisiae as well as in other selected non-Saccharomyces yeasts-Schizosaccharomyces pombe, Kluyveromyces lactis, Candida albicans, Candida glabrata, Cryptococcus neoformans, and Yarrowia lipolytica. Discussed are specificities of Sec14-domain LTPs in various yeasts, their mode of action, subcellular localization, and physiological function. In addition, quite few Sec14 family LTPs are target of antifungal drugs, serve as modifiers of drug resistance or influence virulence of pathologic yeasts. Thus, they represent an important object of study from the perspective of human health.
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Affiliation(s)
- Roman Holič
- Institute of Animal Biochemistry and Genetics, Centre of Biosciences, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Dominik Šťastný
- Institute of Animal Biochemistry and Genetics, Centre of Biosciences, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Peter Griač
- Institute of Animal Biochemistry and Genetics, Centre of Biosciences, Slovak Academy of Sciences, Bratislava, Slovakia.
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21
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Barrera MJ, Aguilera S, Castro I, Carvajal P, Jara D, Molina C, González S, González MJ. Dysfunctional mitochondria as critical players in the inflammation of autoimmune diseases: Potential role in Sjögren's syndrome. Autoimmun Rev 2021; 20:102867. [PMID: 34118452 DOI: 10.1016/j.autrev.2021.102867] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2021] [Accepted: 04/11/2021] [Indexed: 12/13/2022]
Abstract
Relevant reviews highlight the association between dysfunctional mitochondria and inflammation, but few studies address the contribution of mitochondria and mitochondria-endoplasmic reticulum (ER) contact sites (MERCs) to cellular homeostasis and inflammatory signaling. The present review outlines the important role of mitochondria in cellular homeostasis and how dysfunctional mitochondrion can release and misplace mitochondrial components (cardiolipin, mitochondrial DNA (mtDNA), and mitochondrial formylated peptides) through multiple mechanisms. These components can act as damage-associated molecular patterns (DAMPs) and induce an inflammatory response via pattern recognition receptors (PRRs). Accumulation of damaged ROS-generating mitochondria, accompanied by the release of mitochondrial DAMPs, can activate PRRs such as the NLRP3 inflammasome, TLR9, cGAS/STING, and ZBP1. This process would explain the chronic inflammation that is observed in autoimmune diseases such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), type I diabetes (T1D), and Sjögren's syndrome. This review also provides a comprehensive overview of the importance of MERCs to mitochondrial function and morphology, cellular homeostasis, and the inflammatory response. MERCs play an important role in calcium homeostasis by mediating the transfer of calcium from the ER to the mitochondria and thereby facilitating the production of ATP. They also contribute to the synthesis and transfer of phospholipids, protein folding in the ER, mitochondrial fission, mitochondrial fusion, initiation of autophagosome formation, regulation of cell death/survival signaling, and regulation of immune responses. Therefore, alterations within MERCs could increase inflammatory signaling, modulate ER stress responses, cell homeostasis, and ultimately, the cell fate. This study shows severe ultrastructural alterations of mitochondria in salivary gland cells from Sjögren's syndrome patients for the first time, which could trigger alterations in cellular bioenergetics. This finding could explain symptoms such as fatigue and malfunction of the salivary glands in Sjögren's syndrome patients, which would contribute to the chronic inflammatory pathology of the disease. However, this is only a first step in solving this complex puzzle, and several other important factors such as changes in mitochondrial morphology, functionality, and their important contacts with other organelles require further in-depth study. Future work should focus on detecting the key milestones that are related to inflammation in patients with autoimmune diseases, such as Sjögren´s syndrome.
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Affiliation(s)
- María-José Barrera
- Facultad de Odontología, Universidad San Sebastián, Bellavista 7, Santiago, 8420524, Chile
| | | | - Isabel Castro
- Departamento de Tecnología Médica, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Patricia Carvajal
- Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Daniela Jara
- Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Claudio Molina
- Facultad de Odontología, Universidad San Sebastián, Bellavista 7, Santiago, 8420524, Chile
| | - Sergio González
- Escuela de Odontología, Facultad de Ciencias, Universidad Mayor, Santiago, Chile
| | - María-Julieta González
- Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.
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22
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Ashlin TG, Blunsom NJ, Cockcroft S. Courier service for phosphatidylinositol: PITPs deliver on demand. Biochim Biophys Acta Mol Cell Biol Lipids 2021; 1866:158985. [PMID: 34111527 PMCID: PMC8266687 DOI: 10.1016/j.bbalip.2021.158985] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 05/18/2021] [Accepted: 06/01/2021] [Indexed: 12/30/2022]
Abstract
Phosphatidylinositol is the parent lipid for the synthesis of seven phosphorylated inositol lipids and each of them play specific roles in numerous processes including receptor-mediated signalling, actin cytoskeleton dynamics and membrane trafficking. PI synthesis is localised to the endoplasmic reticulum (ER) whilst its phosphorylated derivatives are found in other organelles where the lipid kinases also reside. Phosphorylation of PI to phosphatidylinositol (4,5) bisphosphate (PI(4,5)P2) at the plasma membrane and to phosphatidylinositol 4-phosphate (PI4P) at the Golgi are key events in lipid signalling and Golgi function respectively. Here we review a family of proteins, phosphatidylinositol transfer proteins (PITPs), that can mobilise PI from the ER to provide the substrate to the resident kinases for phosphorylation. Recent studies identify specific and overlapping functions for the three soluble PITPs (PITPα, PITPβ and PITPNC1) in phospholipase C signalling, neuronal function, membrane trafficking, viral replication and in cancer metastases.
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Affiliation(s)
- Tim G Ashlin
- Dept. of Neuroscience, Physiology and Pharmacology, Division of Biosciences, University College London, London WC1E 6JJ, UK
| | - Nicholas J Blunsom
- Dept. of Neuroscience, Physiology and Pharmacology, Division of Biosciences, University College London, London WC1E 6JJ, UK
| | - Shamshad Cockcroft
- Dept. of Neuroscience, Physiology and Pharmacology, Division of Biosciences, University College London, London WC1E 6JJ, UK.
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23
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Qian T, Li C, He R, Wan C, Liu Y, Yu H. Calcium-dependent and -independent lipid transfer mediated by tricalbins in yeast. J Biol Chem 2021; 296:100729. [PMID: 33933446 PMCID: PMC8163979 DOI: 10.1016/j.jbc.2021.100729] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 04/23/2021] [Accepted: 04/28/2021] [Indexed: 11/12/2022] Open
Abstract
Membrane contact sites (MCSs) formed between the endoplasmic reticulum (ER) and the plasma membrane (PM) provide a platform for nonvesicular lipid exchange. The ER-anchored tricalbins (Tcb1, Tcb2, and Tcb3) are critical tethering factors at ER–PM MCSs in yeast. Tricalbins possess a synaptotagmin-like mitochondrial-lipid-binding protein (SMP) domain and multiple Ca2+-binding C2 domains. Although tricalbins have been suggested to be involved in lipid exchange at the ER–PM MCSs, it remains unclear whether they directly mediate lipid transport. Here, using in vitro lipid transfer assays, we discovered that tricalbins are capable of transferring phospholipids between membranes. Unexpectedly, while its lipid transfer activity was markedly elevated by Ca2+, Tcb3 constitutively transferred lipids even in the absence of Ca2+. The stimulatory activity of Ca2+ on Tcb3 required intact Ca2+-binding sites on both the C2C and C2D domains of Tcb3, while Ca2+-independent lipid transport was mediated by the SMP domain that transferred lipids via direct interactions with phosphatidylserine and other negatively charged lipid molecules. These findings establish tricalbins as lipid transfer proteins, and reveal Ca2+-dependent and -independent lipid transfer activities mediated by these tricalbins, providing new insights into their mechanism in maintaining PM integrity at ER–PM MCSs.
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Affiliation(s)
- Tiantian Qian
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Chenlu Li
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Ruyue He
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Chun Wan
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, Colorado, USA
| | - Yinghui Liu
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China.
| | - Haijia Yu
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China.
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24
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Yeo HK, Park TH, Kim HY, Jang H, Lee J, Hwang GS, Ryu SE, Park SH, Song HK, Ban HS, Yoon HJ, Lee BI. Phospholipid transfer function of PTPIP51 at mitochondria-associated ER membranes. EMBO Rep 2021; 22:e51323. [PMID: 33938112 DOI: 10.15252/embr.202051323] [Citation(s) in RCA: 54] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 02/24/2021] [Accepted: 03/22/2021] [Indexed: 01/08/2023] Open
Abstract
In eukaryotic cells, mitochondria are closely tethered to the endoplasmic reticulum (ER) at sites called mitochondria-associated ER membranes (MAMs). Ca2+ ion and phospholipid transfer occurs at MAMs to support diverse cellular functions. Unlike those in yeast, the protein complexes involved in phospholipid transfer at MAMs in humans have not been identified. Here, we determine the crystal structure of the tetratricopeptide repeat domain of PTPIP51 (PTPIP51_TPR), a mitochondrial protein that interacts with the ER-anchored VAPB protein at MAMs. The structure of PTPIP51_TPR shows an archetypal TPR fold, and an electron density map corresponding to an unidentified lipid-like molecule probably derived from the protein expression host is found in the structure. We reveal functions of PTPIP51 in phospholipid binding/transfer, particularly of phosphatidic acid, in vitro. Depletion of PTPIP51 in cells reduces the mitochondrial cardiolipin level. Additionally, we confirm that the PTPIP51-VAPB interaction is mediated by the FFAT-like motif of PTPIP51 and the MSP domain of VAPB. Our findings suggest that PTPIP51 is a phospholipid transfer protein with a MAM-tethering function.
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Affiliation(s)
- Hyun Ku Yeo
- Research Institute, National Cancer Center, Goyang-si, Korea
| | - Tae Hyun Park
- Research Institute, National Cancer Center, Goyang-si, Korea.,Department of Bioengineering, Hanyang University, Seoul, Korea
| | - Hee Yeon Kim
- Research Institute, National Cancer Center, Goyang-si, Korea
| | - Hyonchol Jang
- Research Institute, National Cancer Center, Goyang-si, Korea.,Department of Cancer Biomedical Science, National Cancer Center Graduate School of Cancer Science and Policy, Goyang-si, Korea
| | - Jueun Lee
- Integrated Metabolomics Research Group, Western Seoul Center, Korea Basic Science Institute, Seoul, Korea
| | - Geum-Sook Hwang
- Integrated Metabolomics Research Group, Western Seoul Center, Korea Basic Science Institute, Seoul, Korea.,Department of Chemistry and Nano Science, Ewha Womans University, Seoul, Korea
| | - Seong Eon Ryu
- Department of Bioengineering, Hanyang University, Seoul, Korea
| | - Si Hoon Park
- Department of Life Sciences, Korea University, Seoul, Korea
| | - Hyun Kyu Song
- Department of Life Sciences, Korea University, Seoul, Korea
| | - Hyun Seung Ban
- Korea Research Institute of Bioscience and Biotechnology, Daejeon, Korea
| | - Hye-Jin Yoon
- Department of Chemistry, College of Natural Sciences, Seoul National University, Seoul, Korea
| | - Byung Il Lee
- Research Institute, National Cancer Center, Goyang-si, Korea.,Department of Cancer Biomedical Science, National Cancer Center Graduate School of Cancer Science and Policy, Goyang-si, Korea
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25
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Basak B, Krishnan H, Raghu P. Interdomain interactions regulate the localization of a lipid transfer protein at ER-PM contact sites. Biol Open 2021; 10:bio.057422. [PMID: 33597200 PMCID: PMC7990853 DOI: 10.1242/bio.057422] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
During phospholipase C-β (PLC-β) signalling in Drosophila photoreceptors, the phosphatidylinositol transfer protein (PITP) RDGB, is required for lipid transfer at endoplasmic reticulum (ER)–plasma membrane (PM) contact sites (MCS). Depletion of RDGB or its mis-localization away from the ER–PM MCS results in multiple defects in photoreceptor function. Previously, the interaction between the FFAT motif of RDGB and the integral ER protein dVAP-A was shown to be essential for accurate localization to ER–PM MCS. Here, we report that the FFAT/dVAP-A interaction alone is insufficient to localize RDGB accurately; this also requires the function of the C-terminal domains, DDHD and LNS2. Mutations in each of these domains results in mis-localization of RDGB leading to loss of function. While the LNS2 domain is necessary, it is not sufficient for the correct localization of RDGB, which also requires the C-terminal DDHD domain. The function of the DDHD domain is mediated through an intramolecular interaction with the LNS2 domain. Thus, interactions between the additional domains in a multi-domain PITP together lead to accurate localization at the MCS and signalling function. This article has an associated First Person interview with the first author of the paper. Summary: This study demonstrates interdomain interactions within a phosphatidylinositol transfer protein that regulate its localization and function at an ER-PM membrane contact site.
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Affiliation(s)
- Bishal Basak
- Cellular Organization and Signalling, National Centre for Biological Sciences, TIFR-GKVK Campus, Bellary Road, Bengaluru 560065, India
| | - Harini Krishnan
- Cellular Organization and Signalling, National Centre for Biological Sciences, TIFR-GKVK Campus, Bellary Road, Bengaluru 560065, India
| | - Padinjat Raghu
- Cellular Organization and Signalling, National Centre for Biological Sciences, TIFR-GKVK Campus, Bellary Road, Bengaluru 560065, India
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26
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Abraham S, Ma L, Kong X, Askari S, Edelstein LC, McKenzie SE. PCTP contributes to human platelet activation by enhancing dense granule secretion. Thromb Res 2021; 202:67-73. [PMID: 33770537 DOI: 10.1016/j.thromres.2021.03.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 03/02/2021] [Accepted: 03/03/2021] [Indexed: 10/22/2022]
Abstract
PCTP (phosphatidylcholine transfer protein) was discovered recently to regulate aggregation of human platelets stimulated with PAR4 activating peptide (PAR4AP). However, the role of PCTP following thrombin stimulation, the mechanisms by which PCTP contributes to platelet activation, and the role of PCTP with other receptors remained unknown. As mouse platelets do not express PCTP, we treated human platelets with various agonists in the presence of the specific PCTP inhibitor A1. We observed that PCTP inhibition significantly reduced dense granule secretion in response to thrombin, PAR1AP, PAR4AP, convulxin (GPVI agonist) and FcγRIIA crosslinking. In contrast, among these agonists, PCTP inhibition reduced aggregation only to low dose thrombin and PAR4AP. Unlike its effects on dense granule secretion, PCTP inhibition did not reduce alpha granule secretion in response to thrombin or PAR4AP. PCTP inhibition reduced both the increase in cytoplasmic Ca2+ as well as PKC activity downstream of thrombin. These data are consistent with PCTP contributing to secretion of dense granules, and to being particularly important to human PAR4 early signaling events. Future studies will address further these molecular mechanisms and consequences for hemostasis and thrombosis.
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Affiliation(s)
- Shaji Abraham
- Cardeza Foundation for Hematological Research, Thomas Jefferson University, Jefferson Alumni Hall, 1020 Locust Street, Philadelphia, PA 19107, USA
| | - Lin Ma
- Cardeza Foundation for Hematological Research, Thomas Jefferson University, Jefferson Alumni Hall, 1020 Locust Street, Philadelphia, PA 19107, USA
| | - Xianguo Kong
- Cardeza Foundation for Hematological Research, Thomas Jefferson University, Jefferson Alumni Hall, 1020 Locust Street, Philadelphia, PA 19107, USA
| | - Shayan Askari
- Cardeza Foundation for Hematological Research, Thomas Jefferson University, Jefferson Alumni Hall, 1020 Locust Street, Philadelphia, PA 19107, USA
| | - Leonard C Edelstein
- Cardeza Foundation for Hematological Research, Thomas Jefferson University, Jefferson Alumni Hall, 1020 Locust Street, Philadelphia, PA 19107, USA
| | - Steven E McKenzie
- Cardeza Foundation for Hematological Research, Thomas Jefferson University, Jefferson Alumni Hall, 1020 Locust Street, Philadelphia, PA 19107, USA.
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27
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Li C, Qian T, He R, Wan C, Liu Y, Yu H. Endoplasmic Reticulum-Plasma Membrane Contact Sites: Regulators, Mechanisms, and Physiological Functions. Front Cell Dev Biol 2021; 9:627700. [PMID: 33614657 PMCID: PMC7889955 DOI: 10.3389/fcell.2021.627700] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 01/13/2021] [Indexed: 12/13/2022] Open
Abstract
The endoplasmic reticulum (ER) forms direct membrane contact sites with the plasma membrane (PM) in eukaryotic cells. These ER-PM contact sites play essential roles in lipid homeostasis, ion dynamics, and cell signaling, which are carried out by protein-protein or protein-lipid interactions. Distinct tethering factors dynamically control the architecture of ER-PM junctions in response to intracellular signals or external stimuli. The physiological roles of ER-PM contact sites are dependent on a variety of regulators that individually or cooperatively perform functions in diverse cellular processes. This review focuses on proteins functioning at ER-PM contact sites and highlights the recent progress in their mechanisms and physiological roles.
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Affiliation(s)
- Chenlu Li
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Tiantian Qian
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Ruyue He
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Chun Wan
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, CO, United States
| | - Yinghui Liu
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Haijia Yu
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
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28
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Stieger B, Steiger J, Locher KP. Membrane lipids and transporter function. Biochim Biophys Acta Mol Basis Dis 2021; 1867:166079. [PMID: 33476785 DOI: 10.1016/j.bbadis.2021.166079] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Revised: 12/12/2020] [Accepted: 01/07/2021] [Indexed: 02/07/2023]
Abstract
Transport proteins are essential for cells in allowing the exchange of substances between cells and their environment across the lipid bilayer forming a tight barrier. Membrane lipids modulate the function of transmembrane proteins such as transporters in two ways: Lipids are tightly and specifically bound to transport proteins and in addition they modulate from the bulk of the lipid bilayer the function of transport proteins. This overview summarizes currently available information at the ultrastructural level on lipids tightly bound to transport proteins and the impact of altered bulk membrane lipid composition. Human diseases leading to altered lipid homeostasis will lead to altered membrane lipid composition, which in turn affect the function of transporter proteins.
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Affiliation(s)
- Bruno Stieger
- Department of Clinical Pharmacology and Toxicology, University Hospital Zurich, University of Zurich, 8091 Zurich, Switzerland.
| | - Julia Steiger
- Department of Clinical Pharmacology and Toxicology, University Hospital Zurich, University of Zurich, 8091 Zurich, Switzerland
| | - Kaspar P Locher
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zurich, 8093 Zurich, Switzerland
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29
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Sun A, Simsek Papur O, Dirkx E, Wong L, Sips T, Wang S, Strzelecka A, Nabben M, Glatz JFC, Neumann D, Luiken JJFP. Phosphatidylinositol 4-kinase IIIβ mediates contraction-induced GLUT4 translocation and shows its anti-diabetic action in cardiomyocytes. Cell Mol Life Sci 2020; 78:2839-2856. [PMID: 33090289 PMCID: PMC8004495 DOI: 10.1007/s00018-020-03669-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 08/31/2020] [Accepted: 10/05/2020] [Indexed: 01/15/2023]
Abstract
In the diabetic heart, long-chain fatty acid (LCFA) uptake is increased at the expense of glucose uptake. This metabolic shift ultimately leads to insulin resistance and a reduced cardiac function. Therefore, signaling kinases that mediate glucose uptake without simultaneously stimulating LCFA uptake could be considered attractive anti-diabetic targets. Phosphatidylinositol-4-kinase-IIIβ (PI4KIIIβ) is a lipid kinase downstream of protein kinase D1 (PKD1) that mediates Golgi-to-plasma membrane vesicular trafficking in HeLa-cells. In this study, we evaluated whether PI4KIIIβ is involved in myocellular GLUT4 translocation induced by contraction or oligomycin (an F1F0-ATP synthase inhibitor that activates contraction-like signaling). Pharmacological targeting, with compound MI14, or genetic silencing of PI4KIIIβ inhibited contraction/oligomycin-stimulated GLUT4 translocation and glucose uptake in cardiomyocytes but did not affect CD36 translocation nor LCFA uptake. Addition of the PI4KIIIβ enzymatic reaction product phosphatidylinositol-4-phosphate restored oligomycin-stimulated glucose uptake in the presence of MI14. PI4KIIIβ activation by PKD1 involves Ser294 phosphorylation and altered its localization with unchanged enzymatic activity. Adenoviral PI4KIIIβ overexpression stimulated glucose uptake, but did not activate hypertrophic signaling, indicating that unlike PKD1, PI4KIIIβ is selectively involved in GLUT4 translocation. Finally, PI4KIIIβ overexpression prevented insulin resistance and contractile dysfunction in lipid-overexposed cardiomyocytes. Together, our studies identify PI4KIIIβ as positive and selective regulator of GLUT4 translocation in response to contraction-like signaling, suggesting PI4KIIIβ as a promising target to rescue defective glucose uptake in diabetics.
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Affiliation(s)
- A Sun
- Department of Genetics and Cell Biology, Faculty of Health, Medicine and Life Sciences, Maastricht University Medical Center+, 6200 MD, Maastricht, The Netherlands
| | - O Simsek Papur
- Department of Genetics and Cell Biology, Faculty of Health, Medicine and Life Sciences, Maastricht University Medical Center+, 6200 MD, Maastricht, The Netherlands
| | - E Dirkx
- Department of Genetics and Cell Biology, Faculty of Health, Medicine and Life Sciences, Maastricht University Medical Center+, 6200 MD, Maastricht, The Netherlands
| | - L Wong
- Department of Genetics and Cell Biology, Faculty of Health, Medicine and Life Sciences, Maastricht University Medical Center+, 6200 MD, Maastricht, The Netherlands.,Department of Clinical Genetics, Faculty of Health, Medicine and Life Sciences, Maastricht University Medical Center+, 6200 MD, Maastricht, The Netherlands
| | - T Sips
- Department of Genetics and Cell Biology, Faculty of Health, Medicine and Life Sciences, Maastricht University Medical Center+, 6200 MD, Maastricht, The Netherlands
| | - S Wang
- Department of Genetics and Cell Biology, Faculty of Health, Medicine and Life Sciences, Maastricht University Medical Center+, 6200 MD, Maastricht, The Netherlands
| | - A Strzelecka
- Department of Genetics and Cell Biology, Faculty of Health, Medicine and Life Sciences, Maastricht University Medical Center+, 6200 MD, Maastricht, The Netherlands
| | - M Nabben
- Department of Genetics and Cell Biology, Faculty of Health, Medicine and Life Sciences, Maastricht University Medical Center+, 6200 MD, Maastricht, The Netherlands.,Department of Clinical Genetics, Faculty of Health, Medicine and Life Sciences, Maastricht University Medical Center+, 6200 MD, Maastricht, The Netherlands.,CARIM School for Cardiovascular Diseases, Maastricht, The Netherlands
| | - J F C Glatz
- Department of Genetics and Cell Biology, Faculty of Health, Medicine and Life Sciences, Maastricht University Medical Center+, 6200 MD, Maastricht, The Netherlands.,Department of Clinical Genetics, Faculty of Health, Medicine and Life Sciences, Maastricht University Medical Center+, 6200 MD, Maastricht, The Netherlands
| | - D Neumann
- Department of Pathology, Faculty of Health, Medicine and Life Sciences, Maastricht University Medical Center+, 6200 MD, Maastricht, The Netherlands.,CARIM School for Cardiovascular Diseases, Maastricht, The Netherlands
| | - J J F P Luiken
- Department of Genetics and Cell Biology, Faculty of Health, Medicine and Life Sciences, Maastricht University Medical Center+, 6200 MD, Maastricht, The Netherlands.
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30
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Nath VR, Mishra S, Basak B, Trivedi D, Raghu P. Extended synaptotagmin regulates membrane contact site structure and lipid transfer function in vivo. EMBO Rep 2020; 21:e50264. [PMID: 32716137 DOI: 10.15252/embr.202050264] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 06/12/2020] [Accepted: 06/22/2020] [Indexed: 12/20/2022] Open
Abstract
Inter-organelle communication between closely apposed membranes is proposed at membrane contact sites (MCS). However, the regulation of MCS structure and their functional relevance in vivo remain debated. The extended synaptotagmins (Esyt) are evolutionarily conserved proteins proposed to function at MCS. However, loss of all three Esyts in yeast or mammals shows minimal phenotypes questioning the functional importance of Esyt. We report that in Drosophila photoreceptors, MCS number is regulated by PLCβ activity. Photoreceptors of a null allele of Drosophila extended synaptotagmin (dEsyt) show loss of ER-PM MCS. Loss of dEsyt results in mislocalization of RDGB, an MCS localized lipid transfer protein, required for photoreceptor structure and function, ultimately leading to retinal degeneration. dEsyt depletion enhanced the retinal degeneration, reduced light responses and slower rates of plasma membrane PIP2 resynthesis seen in rdgB mutants. Thus, dEsyt function and PLCβ signaling regulate ER-PM MCS structure and lipid transfer in Drosophila photoreceptors.
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Affiliation(s)
- Vaisaly R Nath
- National Centre for Biological Sciences-TIFR, Bangalore, India.,School of Biotechnology, Amrita Vishwa Vidyapeetham, Amritapuri, Kollam, Kerala, India
| | - Shirish Mishra
- National Centre for Biological Sciences-TIFR, Bangalore, India
| | - Bishal Basak
- National Centre for Biological Sciences-TIFR, Bangalore, India
| | - Deepti Trivedi
- National Centre for Biological Sciences-TIFR, Bangalore, India
| | - Padinjat Raghu
- National Centre for Biological Sciences-TIFR, Bangalore, India
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31
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Phosphatidic acid: an emerging versatile class of cellular mediators. Essays Biochem 2020; 64:533-546. [DOI: 10.1042/ebc20190089] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Revised: 06/01/2020] [Accepted: 06/05/2020] [Indexed: 12/11/2022]
Abstract
Abstract
Lipids function not only as the major structural components of cell membranes, but also as molecular messengers that transduce signals to trigger downstream signaling events in the cell. Phosphatidic acid (PA), the simplest and a minor class of glycerophospholipids, is a key intermediate for the synthesis of membrane and storage lipids, and also plays important roles in mediating diverse cellular and physiological processes in eukaryotes ranging from microbes to mammals and higher plants. PA comprises different molecular species that can act differently, and is found in virtually all organisms, tissues, and organellar membranes, with variations in total content and molecular species composition. The cellular levels of PA are highly dynamic in response to stimuli and multiple enzymatic reactions can mediate its production and degradation. Moreover, its unique physicochemical properties compared with other glycerophospholipids allow PA to influence membrane structure and dynamics, and interact with various proteins. PA has emerged as a class of new lipid mediators modulating various signaling and cellular processes via its versatile effects, such as membrane tethering, conformational changes, and enzymatic activities of target proteins, and vesicular trafficking.
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32
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ER-localized Hrd1 ubiquitinates and inactivates Usp15 to promote TLR4-induced inflammation during bacterial infection. Nat Microbiol 2020; 4:2331-2346. [PMID: 31477895 DOI: 10.1038/s41564-019-0542-2] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The special organelle-located MAVS, STING and TLR3 are important for clearing viral infections. Although TLR4 triggers NF-κB activation to produce pro-inflammatory cytokines for bacterial clearance, effectors with special organelle localization have not been identified. Here, we screened more than 280 E3 ubiquitin ligases and discovered that the endoplasmic reticulum-located Hrd1 regulates TLR4-induced inflammation during bacterial infection. Hrd1 interacts directly with the deubiquitinating enzyme Usp15. Unlike the classical function of Hrd1 in endoplasmic reticulum-associated degradation, Usp15 is not degraded but loses its deubiquitinating activity for IκBα deubiquitination, resulting in excessive NF-κB activation. Importantly, Hrd1 deficiency in macrophages protects mice against lipopolysaccharide-induced septic shock, and knockdown of Usp15 in Hrd1-knockout macrophages restores the reduced IL-6 production. This study proposes that there is crosstalk between Hrd1 and TLR4, thereby linking the endoplasmic reticulum-plasma membrane function during bacterial infection.
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33
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Zung N, Schuldiner M. New horizons in mitochondrial contact site research. Biol Chem 2020; 401:793-809. [PMID: 32324151 DOI: 10.1515/hsz-2020-0133] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 04/14/2020] [Indexed: 12/18/2022]
Abstract
Contact sites, areas where two organelles are held in close proximity through the action of molecular tethers, enable non-vesicular communication between compartments. Mitochondria have been center stage in the contact site field since the discovery of the first contact between mitochondria and the endoplasmic reticulum (ER) over 60 years ago. However, only now, in the last decade, has there been a burst of discoveries regarding contact site biology in general and mitochondrial contacts specifically. The number and types of characterized contacts increased dramatically, new molecular mechanisms enabling contact formation were discovered, additional unexpected functions for contacts were shown, and their roles in cellular and organismal physiology were emphasized. Here, we focus on mitochondria as we highlight the most recent developments, future goals and unresolved questions in the field.
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Affiliation(s)
- Naama Zung
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Maya Schuldiner
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, 7610001, Israel
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34
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Tan JX, Finkel T. Mitochondria as intracellular signaling platforms in health and disease. J Cell Biol 2020; 219:e202002179. [PMID: 32320464 PMCID: PMC7199861 DOI: 10.1083/jcb.202002179] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 04/02/2020] [Accepted: 04/03/2020] [Indexed: 12/15/2022] Open
Abstract
Mitochondria, long viewed solely in the context of bioenergetics, are increasingly emerging as critical hubs for intracellular signaling. Due to their bacterial origin, mitochondria possess their own genome and carry unique lipid components that endow these organelles with specialized properties to help orchestrate multiple signaling cascades. Mitochondrial signaling modulates diverse pathways ranging from metabolism to redox homeostasis to cell fate determination. Here, we review recent progress in our understanding of how mitochondria serve as intracellular signaling platforms with a particular emphasis on lipid-mediated signaling, innate immune activation, and retrograde signaling. We further discuss how these signaling properties might potentially be exploited to develop new therapeutic strategies for a range of age-related conditions.
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Affiliation(s)
- Jay X. Tan
- Aging Institute, University of Pittsburgh School of Medicine/University of Pittsburgh Medical Center, Pittsburgh, PA
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA
| | - Toren Finkel
- Aging Institute, University of Pittsburgh School of Medicine/University of Pittsburgh Medical Center, Pittsburgh, PA
- Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA
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35
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Qin L, Zhou Z, Li Q, Zhai C, Liu L, Quilichini TD, Gao P, Kessler SA, Jaillais Y, Datla R, Peng G, Xiang D, Wei Y. Specific Recruitment of Phosphoinositide Species to the Plant-Pathogen Interfacial Membrane Underlies Arabidopsis Susceptibility to Fungal Infection. THE PLANT CELL 2020; 32:1665-1688. [PMID: 32156686 PMCID: PMC7203932 DOI: 10.1105/tpc.19.00970] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 02/07/2020] [Accepted: 03/09/2020] [Indexed: 05/04/2023]
Abstract
Different phosphoinositides enriched at the membranes of specific subcellular compartments within plant cells contribute to organelle identity, ensuring appropriate cellular trafficking and function. During the infection of plant cells, biotrophic pathogens such as powdery mildews enter plant cells and differentiate into haustoria. Each haustorium is enveloped by an extrahaustorial membrane (EHM) derived from the host plasma membrane. Little is known about the EHM biogenesis and identity. Here, we demonstrate that among the two plasma membrane phosphoinositides in Arabidopsis (Arabidopsis thaliana), PI(4,5)P2 is dynamically up-regulated at powdery mildew infection sites and recruited to the EHM, whereas PI4P is absent in the EHM. Lateral transport of PI(4,5)P2 into the EHM occurs through a brefeldin A-insensitive but actin-dependent trafficking pathway. Furthermore, the lower levels of PI(4,5)P2 in pip5k1 pip5k2 mutants inhibit fungal pathogen development and cause disease resistance, independent of cell death-associated defenses and involving impaired host susceptibility. Our results reveal that plant biotrophic and hemibiotrophic pathogens modulate the subcellular distribution of host phosphoinositides and recruit PI(4,5)P2 as a susceptibility factor for plant disease.
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Affiliation(s)
- Li Qin
- Department of Biology, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2, Canada
| | - Zhuqing Zhou
- Laboratory of Cell Biology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Qiang Li
- Department of Biology, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2, Canada
| | - Chun Zhai
- Saskatoon Research and Development Centre, Agriculture and Agri-Food Canada, Saskatoon, Saskatchewan S7N 0X2, Canada
| | - Lijiang Liu
- Department of Biology, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2, Canada
- Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan, Hubei 430062, China
| | | | - Peng Gao
- Global Institute for Food Security, University of Saskatchewan, Saskatoon, Saskatchewan S7N 0W9, Canada
| | - Sharon A Kessler
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana 47907
| | - Yvon Jaillais
- Laboratoire Reproduction et Développement des Plantes, Université de Lyon, École normale supérieure de Lyon, Université Claude Bernard Lyon 1, CNRS, INRA, Lyon 69342, France
| | - Raju Datla
- Global Institute for Food Security, University of Saskatchewan, Saskatoon, Saskatchewan S7N 0W9, Canada
| | - Gary Peng
- Saskatoon Research and Development Centre, Agriculture and Agri-Food Canada, Saskatoon, Saskatchewan S7N 0X2, Canada
| | - Daoquan Xiang
- National Research Council Canada, Saskatoon, Saskatchewan S7N 0W9, Canada
| | - Yangdou Wei
- Department of Biology, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2, Canada
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36
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How is the acyl chain composition of phosphoinositides created and does it matter? Biochem Soc Trans 2020; 47:1291-1305. [PMID: 31657437 PMCID: PMC6824679 DOI: 10.1042/bst20190205] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 09/27/2019] [Accepted: 10/01/2019] [Indexed: 12/11/2022]
Abstract
The phosphoinositide (PIPn) family of signalling phospholipids are central regulators in membrane cell biology. Their varied functions are based on the phosphorylation pattern of their inositol ring, which can be recognized by selective binding domains in their effector proteins and be modified by a series of specific PIPn kinases and phosphatases, which control their interconversion in a spatial and temporal manner. Yet, a unique feature of PIPns remains largely unexplored: their unusually uniform acyl chain composition. Indeed, while most phospholipids present a range of molecular species comprising acyl chains of diverse length and saturation, PIPns in several organisms and tissues show the predominance of a single hydrophobic backbone, which in mammals is composed of arachidonoyl and stearoyl chains. Despite evolution having favoured this specific PIPn configuration, little is known regarding the mechanisms and functions behind it. In this review, we explore the metabolic pathways that could control the acyl chain composition of PIPns as well as the potential roles of this selective enrichment. While our understanding of this phenomenon has been constrained largely by the technical limitations in the methods traditionally employed in the PIPn field, we believe that the latest developments in PIPn analysis should shed light onto this old question.
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Jurkiewicz P, Senicourt L, Ayeb H, Lequin O, Lacapere JJ, Batoko H. A Plant-Specific N-terminal Extension Reveals Evolutionary Functional Divergence within Translocator Proteins. iScience 2020; 23:100889. [PMID: 32087576 PMCID: PMC7033594 DOI: 10.1016/j.isci.2020.100889] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 11/30/2019] [Accepted: 02/03/2020] [Indexed: 12/13/2022] Open
Abstract
Conserved translocator proteins (TSPOs) mediate cell stress responses possibly in a cell-type-specific manner. This work reports on the molecular function of plant TSPO and their possible evolutionary divergence. Arabidopsis thaliana TSPO (AtTSPO) is stress induced and has a conserved polybasic, plant-specific N-terminal extension. AtTSPO reduces water loss by depleting aquaporin PIP2;7 in the plasma membrane. Herein, AtTSPO was found to bind phosphoinositides in vitro, but only full-length AtTSPO or chimeric mouse TSPO with an AtTSPO N-terminus bound PI(4,5)P2in vitro and modified PIP2;7 levels in vivo. Expression of AtTSPO but not its N-terminally truncated variant enhanced phospholipase C activity and depleted PI(4,5)P2 from the plasma membrane and its enrichment in Golgi membranes. Deletion or point mutations within the AtTSPO N-terminus affected PI(4,5)P2 binding and almost prevented AtTSPO-PIP2;7 interaction in vivo. The findings imply functional divergence of plant TSPOs from bacterial and animal counterparts via evolutionary acquisition of the phospholipid-interacting N-terminus.
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Affiliation(s)
- Pawel Jurkiewicz
- Louvain Institute of Biomolecular Science and Technology (LIBST), University of Louvain (UCLouvain), Croix du Sud 4-5, L7.07.14, 1348 Louvain-la-Neuve, Belgium
| | - Lucile Senicourt
- Sorbonne Université, École Normale Supérieure, PSL University, CNRS, Laboratoire des Biomolécules, 4 Place Jussieu, 75005 Paris, France
| | - Haitham Ayeb
- Louvain Institute of Biomolecular Science and Technology (LIBST), University of Louvain (UCLouvain), Croix du Sud 4-5, L7.07.14, 1348 Louvain-la-Neuve, Belgium
| | - Olivier Lequin
- Sorbonne Université, École Normale Supérieure, PSL University, CNRS, Laboratoire des Biomolécules, 4 Place Jussieu, 75005 Paris, France
| | - Jean-Jacques Lacapere
- Sorbonne Université, École Normale Supérieure, PSL University, CNRS, Laboratoire des Biomolécules, 4 Place Jussieu, 75005 Paris, France
| | - Henri Batoko
- Louvain Institute of Biomolecular Science and Technology (LIBST), University of Louvain (UCLouvain), Croix du Sud 4-5, L7.07.14, 1348 Louvain-la-Neuve, Belgium.
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Schrader M, Kamoshita M, Islinger M. Organelle interplay-peroxisome interactions in health and disease. J Inherit Metab Dis 2020; 43:71-89. [PMID: 30864148 PMCID: PMC7041636 DOI: 10.1002/jimd.12083] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 02/28/2019] [Accepted: 03/06/2019] [Indexed: 01/04/2023]
Abstract
Peroxisomes are multifunctional, dynamic, membrane-bound organelles with important functions in cellular lipid metabolism, rendering them essential for human health and development. Important roles for peroxisomes in signaling and the fine-tuning of cellular processes are emerging, which integrate them in a complex network of interacting cellular compartments. Like many other organelles, peroxisomes communicate through membrane contact sites. For example, peroxisomal growth, positioning, and lipid metabolism involves contacts with the endoplasmic reticulum (ER). Here, we discuss the most recent findings on peroxisome-organelle interactions including peroxisome-ER interplay at membrane contacts sites, and functional interplay with mitochondria, lysosomes, and lipid droplets in mammalian cells. We address tether proteins, metabolic cooperation, and the impact of peroxisome interactions on human health and disease.
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Affiliation(s)
- Michael Schrader
- College of Life and Environmental Sciences, BiosciencesUniversity of ExeterExeterUK
| | - Maki Kamoshita
- College of Life and Environmental Sciences, BiosciencesUniversity of ExeterExeterUK
| | - Markus Islinger
- Institute of Neuroanatomy, Center for Biomedicine and Medical Technology Mannheim, Medical Faculty ManheimUniversity of HeidelbergMannheimGermany
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Hu J, Gao M, Wang Y, Liu M, Wang J, Li J, Song Z, Chen Y, Wang Z. Imaging the Substructures of Individual IgE Antibodies with Atomic Force Microscopy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:14896-14901. [PMID: 31661619 DOI: 10.1021/acs.langmuir.9b02631] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The interactions between antibodies and substrates directly affect their conformations and thus their immune functions. Therefore, it is desirable to study the structures of antibodies at the single molecule level. Herein, the substructures of Immunoglobulin E (IgE) on solid surfaces were investigated. For this purpose, tapping-mode atomic force microscopy (AFM) was applied to observe individual IgE substructures adsorbed onto Mg2+ and Na+ modified mica substrates in air. As expected, the AFM images revealed that the IgE antibodies exhibited different conformations on the surface of mica substrate consisting of the four basic orientations: three domain, two equivalent domain, two unequal domain, and single domain morphologies. Moreover, the differences in the different orientations in single IgE antibodies were also identified clearly.
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Affiliation(s)
- Jing Hu
- Ministry of Education Key Laboratory for Cross-Scale Micro and Nano Manufacturing , Changchun University of Science and Technology , Changchun 130022 , China
- International Research Centre for Nano Handling and Manufacturing of China , Changchun University of Science and Technology , Changchun 130022 , China
| | - Mingyan Gao
- Ministry of Education Key Laboratory for Cross-Scale Micro and Nano Manufacturing , Changchun University of Science and Technology , Changchun 130022 , China
- International Research Centre for Nano Handling and Manufacturing of China , Changchun University of Science and Technology , Changchun 130022 , China
| | - Ying Wang
- Ministry of Education Key Laboratory for Cross-Scale Micro and Nano Manufacturing , Changchun University of Science and Technology , Changchun 130022 , China
- International Research Centre for Nano Handling and Manufacturing of China , Changchun University of Science and Technology , Changchun 130022 , China
| | - Mengnan Liu
- Ministry of Education Key Laboratory for Cross-Scale Micro and Nano Manufacturing , Changchun University of Science and Technology , Changchun 130022 , China
- International Research Centre for Nano Handling and Manufacturing of China , Changchun University of Science and Technology , Changchun 130022 , China
| | - Jianfei Wang
- Ministry of Education Key Laboratory for Cross-Scale Micro and Nano Manufacturing , Changchun University of Science and Technology , Changchun 130022 , China
- International Research Centre for Nano Handling and Manufacturing of China , Changchun University of Science and Technology , Changchun 130022 , China
| | - Jiani Li
- Ministry of Education Key Laboratory for Cross-Scale Micro and Nano Manufacturing , Changchun University of Science and Technology , Changchun 130022 , China
- International Research Centre for Nano Handling and Manufacturing of China , Changchun University of Science and Technology , Changchun 130022 , China
| | - Zhengxun Song
- Ministry of Education Key Laboratory for Cross-Scale Micro and Nano Manufacturing , Changchun University of Science and Technology , Changchun 130022 , China
- International Research Centre for Nano Handling and Manufacturing of China , Changchun University of Science and Technology , Changchun 130022 , China
| | - Yujuan Chen
- Ministry of Education Key Laboratory for Cross-Scale Micro and Nano Manufacturing , Changchun University of Science and Technology , Changchun 130022 , China
- International Research Centre for Nano Handling and Manufacturing of China , Changchun University of Science and Technology , Changchun 130022 , China
- School of Life Sciences , Changchun University of Science and Technology , Changchun 130022 , China
| | - Zuobin Wang
- Ministry of Education Key Laboratory for Cross-Scale Micro and Nano Manufacturing , Changchun University of Science and Technology , Changchun 130022 , China
- International Research Centre for Nano Handling and Manufacturing of China , Changchun University of Science and Technology , Changchun 130022 , China
- JR3CN & IRAC , University of Bedfordshire , Luton LU1 3JU , U.K
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Collado J, Kalemanov M, Campelo F, Bourgoint C, Thomas F, Loewith R, Martínez-Sánchez A, Baumeister W, Stefan CJ, Fernández-Busnadiego R. Tricalbin-Mediated Contact Sites Control ER Curvature to Maintain Plasma Membrane Integrity. Dev Cell 2019; 51:476-487.e7. [PMID: 31743662 PMCID: PMC6863395 DOI: 10.1016/j.devcel.2019.10.018] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 09/23/2019] [Accepted: 10/16/2019] [Indexed: 12/23/2022]
Abstract
Membrane contact sites (MCS) between the endoplasmic reticulum (ER) and the plasma membrane (PM) play fundamental roles in all eukaryotic cells. ER-PM MCS are particularly abundant in Saccharomyces cerevisiae, where approximately half of the PM surface is covered by cortical ER (cER). Several proteins, including Ist2, Scs2/22, and Tcb1/2/3 are implicated in cER formation, but the specific roles of these molecules are poorly understood. Here, we use cryo-electron tomography to show that ER-PM tethers are key determinants of cER morphology. Notably, Tcb proteins (tricalbins) form peaks of extreme curvature on the cER membrane facing the PM. Combined modeling and functional assays suggest that Tcb-mediated cER peaks facilitate the transport of lipids between the cER and the PM, which is necessary to maintain PM integrity under heat stress. ER peaks were also present at other MCS, implying that membrane curvature enforcement may be a widespread mechanism to regulate MCS function.
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Affiliation(s)
- Javier Collado
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, Martinsried 82152, Germany; Institute of Neuropathology, University Medical Center Göttingen, Göttingen 37099, Germany; Graduate School of Quantitative Biosciences Munich, Munich 81337, Germany
| | - Maria Kalemanov
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, Martinsried 82152, Germany; Graduate School of Quantitative Biosciences Munich, Munich 81337, Germany
| | - Felix Campelo
- ICFO, Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels 08860, Spain
| | - Clélia Bourgoint
- Department of Molecular Biology, University of Geneva, Geneva 1211, Switzerland
| | - Ffion Thomas
- MRC Laboratory for Molecular Cell Biology, University College London, London, WC1E 6BT, UK
| | - Robbie Loewith
- Department of Molecular Biology, University of Geneva, Geneva 1211, Switzerland; Swiss National Centre for Competence in Research, Program Chemical Biology, Geneva 1211, Switzerland
| | - Antonio Martínez-Sánchez
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, Martinsried 82152, Germany
| | - Wolfgang Baumeister
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, Martinsried 82152, Germany
| | - Christopher J Stefan
- MRC Laboratory for Molecular Cell Biology, University College London, London, WC1E 6BT, UK
| | - Rubén Fernández-Busnadiego
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, Martinsried 82152, Germany; Institute of Neuropathology, University Medical Center Göttingen, Göttingen 37099, Germany; Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, Göttingen, Germany.
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Pevalová Z, Pevala V, Blunsom NJ, Tahotná D, Kotrasová V, Holič R, Pokorná L, Bauer JA, Kutejová E, Cockcroft S, Griač P. Yeast phosphatidylinositol transfer protein Pdr17 does not require high affinity phosphatidylinositol binding for its cellular function. Biochim Biophys Acta Mol Cell Biol Lipids 2019; 1864:1412-1421. [DOI: 10.1016/j.bbalip.2019.07.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 07/09/2019] [Indexed: 11/28/2022]
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Raghu P, Joseph A, Krishnan H, Singh P, Saha S. Phosphoinositides: Regulators of Nervous System Function in Health and Disease. Front Mol Neurosci 2019; 12:208. [PMID: 31507376 PMCID: PMC6716428 DOI: 10.3389/fnmol.2019.00208] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2019] [Accepted: 08/07/2019] [Indexed: 12/11/2022] Open
Abstract
Phosphoinositides, the seven phosphorylated derivatives of phosphatidylinositol have emerged as regulators of key sub-cellular processes such as membrane transport, cytoskeletal function and plasma membrane signaling in eukaryotic cells. All of these processes are also present in the cells that constitute the nervous system of animals and in this setting too, these are likely to tune key aspects of cell biology in relation to the unique structure and function of neurons. Phosphoinositides metabolism and function are mediated by enzymes and proteins that are conserved in evolution, and analysis of knockouts of these in animal models implicate this signaling system in neural function. Most recently, with the advent of human genome analysis, mutations in genes encoding components of the phosphoinositide signaling pathway have been implicated in human diseases although the cell biological basis of disease phenotypes in many cases remains unclear. In this review we evaluate existing evidence for the involvement of phosphoinositide signaling in human nervous system diseases and discuss ways of enhancing our understanding of the role of this pathway in the human nervous system's function in health and disease.
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Affiliation(s)
- Padinjat Raghu
- National Centre for Biological Sciences-TIFR, Bengaluru, India
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Abstract
The outer membrane (OM) of Gram-negative bacteria exhibits unique lipid asymmetry, with lipopolysaccharides (LPS) residing in the outer leaflet and phospholipids (PLs) in the inner leaflet. This asymmetric bilayer protects the bacterium against intrusion of many toxic substances, including antibiotics and detergents, yet allows acquisition of nutrients necessary for growth. To build the OM and ensure its proper function, the cell produces OM constituents in the cytoplasm or inner membrane and transports these components across the aqueous periplasmic space separating the two membranes. Of note, the processes by which the most basic membrane building blocks, i.e. PLs, are shuttled across the cell envelope remain elusive. This review highlights our current understanding (or lack thereof) of bacterial PL trafficking, with a focus on recent developments in the field. We adopt a mechanistic approach and draw parallels and comparisons with well-characterized systems, particularly OM lipoprotein and LPS transport, to illustrate key challenges in intermembrane lipid trafficking. Pathways that transport PLs across the bacterial cell envelope are fundamental to OM biogenesis and homeostasis and are potential molecular targets that could be exploited for antibiotic development.
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Affiliation(s)
- Rahul Shrivastava
- Department of Chemistry, National University of Singapore, Singapore 117543, Singapore
| | - Shu-Sin Chng
- Department of Chemistry, National University of Singapore, Singapore 117543, Singapore
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Bozelli JC, Epand RM. Role of membrane shape in regulating the phosphatidylinositol cycle at contact sites. Chem Phys Lipids 2019; 221:24-29. [DOI: 10.1016/j.chemphyslip.2019.03.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 02/25/2019] [Accepted: 03/01/2019] [Indexed: 01/09/2023]
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45
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Balla T, Sengupta N, Kim YJ. Lipid synthesis and transport are coupled to regulate membrane lipid dynamics in the endoplasmic reticulum. Biochim Biophys Acta Mol Cell Biol Lipids 2019; 1865:158461. [PMID: 31108203 DOI: 10.1016/j.bbalip.2019.05.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 05/10/2019] [Accepted: 05/15/2019] [Indexed: 11/27/2022]
Abstract
Structural lipids are mostly synthesized in the endoplasmic reticulum (ER), from which they are actively transported to the membranes of other organelles. Lipids can leave the ER through vesicular trafficking or non-vesicular lipid transfer and, curiously, both processes can be regulated either by the transported lipid cargos themselves or by different secondary lipid species. For most structural lipids, transport out of the ER membrane is a key regulatory component controlling their synthesis. Distribution of the lipids between the two leaflets of the ER bilayer or between the ER and other membranes is also critical for maintaining the unique membrane properties of each cellular organelle. How cells integrate these processes within the ER depends on fine spatial segregation of the molecular components and intricate metabolic channeling, both of which we are only beginning to understand. This review will summarize some of these complex processes and attempt to identify the organizing principles that start to emerge. This article is part of a Special Issue entitled Endoplasmic reticulum platforms for lipid dynamics edited by Shamshad Cockcroft and Christopher Stefan.
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Affiliation(s)
- Tamas Balla
- Section on Molecular Signal Transduction, Program for Developmental Neuroscience, Eunice Kennedy Shriver NICHD, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Nivedita Sengupta
- Section on Molecular Signal Transduction, Program for Developmental Neuroscience, Eunice Kennedy Shriver NICHD, National Institutes of Health, Bethesda, MD 20892, USA
| | - Yeun Ju Kim
- Section on Molecular Signal Transduction, Program for Developmental Neuroscience, Eunice Kennedy Shriver NICHD, National Institutes of Health, Bethesda, MD 20892, USA
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Funato K, Riezman H, Muñiz M. Vesicular and non-vesicular lipid export from the ER to the secretory pathway. Biochim Biophys Acta Mol Cell Biol Lipids 2019; 1865:158453. [PMID: 31054928 DOI: 10.1016/j.bbalip.2019.04.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 12/20/2018] [Accepted: 01/06/2019] [Indexed: 11/26/2022]
Abstract
The endoplasmic reticulum is the site of synthesis of most glycerophospholipids, neutral lipids and the initial steps of sphingolipid biosynthesis of the secretory pathway. After synthesis, these lipids are distributed within the cells to create and maintain the specific compositions of the other secretory organelles. This represents a formidable challenge, particularly while there is a simultaneous and quantitatively important flux of membrane components stemming from the vesicular traffic of proteins through the pathway, which can also vary depending on the cell type and status. To meet this challenge cells have developed an intricate system of interorganellar contacts and lipid transport proteins, functioning in non-vesicular lipid transport, which are able to ensure membrane lipid homeostasis even in the absence of membrane trafficking. Nevertheless, under normal conditions, lipids are transported in cells by both vesicular and non-vesicular mechanisms. In this review we will discuss the mechanism and roles of vesicular and non-vesicular transport of lipids from the ER to other organelles of the secretory pathway.
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Affiliation(s)
- Kouichi Funato
- Department of Bioresource Science and Technology, Hiroshima University, Japan.
| | - Howard Riezman
- NCCR Chemical Biology and Department of Biochemistry, Sciences II, University of Geneva, Switzerland.
| | - Manuel Muñiz
- Department of Cell Biology, University of Seville, 41012 Seville, Spain; Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Spain.
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Membrane Lipid Composition: Effect on Membrane and Organelle Structure, Function and Compartmentalization and Therapeutic Avenues. Int J Mol Sci 2019; 20:ijms20092167. [PMID: 31052427 PMCID: PMC6540057 DOI: 10.3390/ijms20092167] [Citation(s) in RCA: 391] [Impact Index Per Article: 78.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 04/26/2019] [Accepted: 04/30/2019] [Indexed: 12/17/2022] Open
Abstract
Biological membranes are key elements for the maintenance of cell architecture and physiology. Beyond a pure barrier separating the inner space of the cell from the outer, the plasma membrane is a scaffold and player in cell-to-cell communication and the initiation of intracellular signals among other functions. Critical to this function is the plasma membrane compartmentalization in lipid microdomains that control the localization and productive interactions of proteins involved in cell signal propagation. In addition, cells are divided into compartments limited by other membranes whose integrity and homeostasis are finely controlled, and which determine the identity and function of the different organelles. Here, we review current knowledge on membrane lipid composition in the plasma membrane and endomembrane compartments, emphasizing its role in sustaining organelle structure and function. The correct composition and structure of cell membranes define key pathophysiological aspects of cells. Therefore, we explore the therapeutic potential of manipulating membrane lipid composition with approaches like membrane lipid therapy, aiming to normalize cell functions through the modification of membrane lipid bilayers.
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