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Rogov VV, Nezis IP, Tsapras P, Zhang H, Dagdas Y, Noda NN, Nakatogawa H, Wirth M, Mouilleron S, McEwan DG, Behrends C, Deretic V, Elazar Z, Tooze SA, Dikic I, Lamark T, Johansen T. Atg8 family proteins, LIR/AIM motifs and other interaction modes. Autophagy Rep 2023; 2:27694127.2023.2188523. [PMID: 38214012 PMCID: PMC7615515 DOI: 10.1080/27694127.2023.2188523] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/13/2024]
Abstract
The Atg8 family of ubiquitin-like proteins play pivotal roles in autophagy and other processes involving vesicle fusion and transport where the lysosome/vacuole is the end station. Nuclear roles of Atg8 proteins are also emerging. Here, we review the structural and functional features of Atg8 family proteins and their protein-protein interaction modes in model organisms such as yeast, Arabidopsis, C. elegans and Drosophila to humans. Although varying in number of homologs, from one in yeast to seven in humans, and more than ten in some plants, there is a strong evolutionary conservation of structural features and interaction modes. The most prominent interaction mode is between the LC3 interacting region (LIR), also called Atg8 interacting motif (AIM), binding to the LIR docking site (LDS) in Atg8 homologs. There are variants of these motifs like "half-LIRs" and helical LIRs. We discuss details of the binding modes and how selectivity is achieved as well as the role of multivalent LIR-LDS interactions in selective autophagy. A number of LIR-LDS interactions are known to be regulated by phosphorylation. New methods to predict LIR motifs in proteins have emerged that will aid in discovery and analyses. There are also other interaction surfaces than the LDS becoming known where we presently lack detailed structural information, like the N-terminal arm region and the UIM-docking site (UDS). More interaction modes are likely to be discovered in future studies.
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Affiliation(s)
- Vladimir V. Rogov
- Institute for Pharmaceutical Chemistry, Department of Biochemistry, Chemistry and Pharmacy, Goethe University, 60438 Frankfurt, am Main, and Structural Genomics Consortium, Buchmann Institute for Molecular Life Sciences, Goethe University, 60438 Frankfurt am Main, Germany
| | - Ioannis P. Nezis
- School of Life Sciences, University of Warwick, CV4 7AL Coventry, UK
| | | | - Hong Zhang
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China and College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Yasin Dagdas
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, Vienna, Austria
| | - Nobuo N. Noda
- Institute for Genetic Medicine, Hokkaido University, Kita 15, Nishi 7, Kita-ku, Sapporo 060-0815, Japan
| | - Hitoshi Nakatogawa
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Martina Wirth
- Molecular Cell Biology of Autophagy, The Francis Crick Institute, London, UK
| | - Stephane Mouilleron
- Structural Biology Science Technology Platform, The Francis Crick Institute, London, UK
| | | | - Christian Behrends
- Munich Cluster of Systems Neurology, Ludwig-Maximilians-Universität München, München, Germany
| | - Vojo Deretic
- Autophagy, Inflammation and Metabolism Center of Biochemical Research Excellence, Albuquerque, NM and Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, NM
| | - Zvulun Elazar
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot, Israel
| | - Sharon A. Tooze
- Molecular Cell Biology of Autophagy, The Francis Crick Institute, London, UK
| | - Ivan Dikic
- Institute of Biochemistry II, Medical Faculty, Goethe-University, Frankfurt am Main, and Buchmann Institute for Molecular Life Sciences, Frankfurt am Main, Germany
| | - Trond Lamark
- Autophagy Research Group, Department of Medical Biology, University of Tromsø - The Arctic University of Norway, Tromsø, Norway
| | - Terje Johansen
- Autophagy Research Group, Department of Medical Biology, University of Tromsø - The Arctic University of Norway, Tromsø, Norway
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2
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Cross J, Durgan J, McEwan DG, Tayler M, Ryan KM, Florey O. Lysosome damage triggers direct ATG8 conjugation and ATG2 engagement via non-canonical autophagy. J Cell Biol 2023; 222:e202303078. [PMID: 37796195 PMCID: PMC10561555 DOI: 10.1083/jcb.202303078] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 07/14/2023] [Accepted: 09/07/2023] [Indexed: 10/06/2023] Open
Abstract
Cells harness multiple pathways to maintain lysosome integrity, a central homeostatic process. Damaged lysosomes can be repaired or targeted for degradation by lysophagy, a selective autophagy process involving ATG8/LC3. Here, we describe a parallel ATG8/LC3 response to lysosome damage, mechanistically distinct from lysophagy. Using a comprehensive series of biochemical, pharmacological, and genetic approaches, we show that lysosome damage induces non-canonical autophagy and Conjugation of ATG8s to Single Membranes (CASM). Following damage, ATG8s are rapidly and directly conjugated onto lysosome membranes, independently of ATG13/WIPI2, lipidating to PS (and PE), a molecular hallmark of CASM. Lysosome damage drives V-ATPase V0-V1 association, direct recruitment of ATG16L1 via its WD40-domain/K490A, and is sensitive to Salmonella SopF. Lysosome damage-induced CASM is associated with formation of dynamic, LC3A-positive tubules, and promotes robust LC3A engagement with ATG2, a lipid transfer protein central to lysosome repair. Together, our data identify direct ATG8 conjugation as a rapid response to lysosome damage, with important links to lipid transfer and dynamics.
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Affiliation(s)
- Jake Cross
- Signalling Programme, Babraham Institute, Cambridge, UK
| | - Joanne Durgan
- Signalling Programme, Babraham Institute, Cambridge, UK
| | - David G. McEwan
- Tumour Cell Death and Autophagy Laboratory, Cancer Research UK Beatson Institute, Glasgow, UK
| | | | - Kevin M. Ryan
- Tumour Cell Death and Autophagy Laboratory, Cancer Research UK Beatson Institute, Glasgow, UK
| | - Oliver Florey
- Signalling Programme, Babraham Institute, Cambridge, UK
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3
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Kania E, Long JS, McEwan DG, Welkenhuyzen K, La Rovere R, Luyten T, Halpin J, Lobbestael E, Baekelandt V, Bultynck G, Ryan KM, Parys JB. LRRK2 phosphorylation status and kinase activity regulate (macro)autophagy in a Rab8a/Rab10-dependent manner. Cell Death Dis 2023; 14:436. [PMID: 37454104 PMCID: PMC10349885 DOI: 10.1038/s41419-023-05964-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 06/27/2023] [Accepted: 07/06/2023] [Indexed: 07/18/2023]
Abstract
Mutations in the leucine-rich repeat kinase 2 (LRRK2) gene are the most common genetic cause of Parkinson's disease (PD), with growing importance also for Crohn's disease and cancer. LRRK2 is a large and complex protein possessing both GTPase and kinase activity. Moreover, LRRK2 activity and function can be influenced by its phosphorylation status. In this regard, many LRRK2 PD-associated mutants display decreased phosphorylation of the constitutive phosphorylation cluster S910/S935/S955/S973, but the role of these changes in phosphorylation status with respect to LRRK2 physiological functions remains unknown. Here, we propose that the S910/S935/S955/S973 phosphorylation sites act as key regulators of LRRK2-mediated autophagy under both basal and starvation conditions. We show that quadruple LRRK2 phosphomutant cells (4xSA; S910A/S935A/S955A/S973A) have impaired lysosomal functionality and fail to induce and proceed with autophagy during starvation. In contrast, treatment with the specific LRRK2 kinase inhibitors MLi-2 (100 nM) or PF-06447475 (150 nM), which also led to decreased LRRK2 phosphorylation of S910/S935/S955/S973, did not affect autophagy. In explanation, we demonstrate that the autophagy impairment due to the 4xSA LRRK2 phospho-dead mutant is driven by its enhanced LRRK2 kinase activity. We show mechanistically that this involves increased phosphorylation of LRRK2 downstream targets Rab8a and Rab10, as the autophagy impairment in 4xSA LRRK2 cells is counteracted by expression of phosphorylation-deficient mutants T72A Rab8a and T73A Rab10. Similarly, reduced autophagy and decreased LRRK2 phosphorylation at the constitutive sites were observed in cells expressing the pathological R1441C LRRK2 PD mutant, which also displays increased kinase activity. These data underscore the relation between LRRK2 phosphorylation at its constitutive sites and the importance of increased LRRK2 kinase activity in autophagy regulation and PD pathology.
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Affiliation(s)
- Elżbieta Kania
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow, G61 1BD, UK
- Institute of Cancer Sciences, University of Glasgow, Garscube Estate, Switchback Road, Glasgow, G61 1QH, UK
- Laboratory of Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine & Leuven Kanker Instituut, KU Leuven, Herestraat 49, Campus Gasthuisberg O&NI - B802, 3000, Leuven, Belgium
| | - Jaclyn S Long
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow, G61 1BD, UK
- Institute of Cancer Sciences, University of Glasgow, Garscube Estate, Switchback Road, Glasgow, G61 1QH, UK
| | - David G McEwan
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow, G61 1BD, UK
- Institute of Cancer Sciences, University of Glasgow, Garscube Estate, Switchback Road, Glasgow, G61 1QH, UK
| | - Kirsten Welkenhuyzen
- Laboratory of Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine & Leuven Kanker Instituut, KU Leuven, Herestraat 49, Campus Gasthuisberg O&NI - B802, 3000, Leuven, Belgium
| | - Rita La Rovere
- Laboratory of Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine & Leuven Kanker Instituut, KU Leuven, Herestraat 49, Campus Gasthuisberg O&NI - B802, 3000, Leuven, Belgium
| | - Tomas Luyten
- Laboratory of Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine & Leuven Kanker Instituut, KU Leuven, Herestraat 49, Campus Gasthuisberg O&NI - B802, 3000, Leuven, Belgium
| | - John Halpin
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow, G61 1BD, UK
- Institute of Cancer Sciences, University of Glasgow, Garscube Estate, Switchback Road, Glasgow, G61 1QH, UK
| | - Evy Lobbestael
- Laboratory for Neurobiology and Gene Therapy, Department of Neurosciences & Leuven Brain Institute, KU Leuven, Herestraat 49, Campus Gasthuisberg B1023, 3000, Leuven, Belgium
| | - Veerle Baekelandt
- Laboratory for Neurobiology and Gene Therapy, Department of Neurosciences & Leuven Brain Institute, KU Leuven, Herestraat 49, Campus Gasthuisberg B1023, 3000, Leuven, Belgium
| | - Geert Bultynck
- Laboratory of Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine & Leuven Kanker Instituut, KU Leuven, Herestraat 49, Campus Gasthuisberg O&NI - B802, 3000, Leuven, Belgium
| | - Kevin M Ryan
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow, G61 1BD, UK.
- Institute of Cancer Sciences, University of Glasgow, Garscube Estate, Switchback Road, Glasgow, G61 1QH, UK.
| | - Jan B Parys
- Laboratory of Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine & Leuven Kanker Instituut, KU Leuven, Herestraat 49, Campus Gasthuisberg O&NI - B802, 3000, Leuven, Belgium.
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4
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McEwan DG, Ryan KM. ATG2 and VPS13 proteins: molecular highways transporting lipids to drive membrane expansion and organelle communication. FEBS J 2022; 289:7113-7127. [PMID: 34783437 DOI: 10.1111/febs.16280] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 11/03/2021] [Accepted: 11/15/2021] [Indexed: 01/13/2023]
Abstract
Communication between organelles is an essential process that helps maintain cellular homeostasis and organelle contact sites have recently emerged as crucial mediators of this communication. The emergence of a class of molecular bridges that span the inter-organelle gaps has now been shown to direct the flow of lipid traffic from one lipid bilayer to another. One of the key components of these molecular bridges is the presence of an N-terminal Chorein/VPS13 domain. This is an evolutionarily conserved domain present in multiple proteins within the endocytic and autophagy trafficking pathways. Herein, we discuss the current state-of-the-art of this class of proteins, focusing on the role of these lipid transporters in the autophagy and endocytic pathways. We discuss the recent biochemical and structural advances that have highlighted the essential role Chorein-N domain containing ATG2 proteins play in driving the formation of the autophagosome and how lipids are transported from the endoplasmic reticulum to the growing phagophore. We also consider the VPS13 proteins, their role in organelle contacts and the endocytic pathway and highlight how disease-causing mutations disrupt these contact sites. Finally, we open the door to discuss other Chorein_N domain containing proteins, for instance, UHRF1BP1/1L, their role in disease and look towards prokaryote examples of Chorein_N-like domains. Taken together, recent advances have highlighted an exciting opportunity to delve deeper into inter-organelle communication and understand how lipids are transported between membrane bilayers and how this process is disrupted in multiple diseases.
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Affiliation(s)
| | - Kevin M Ryan
- Cancer Research UK Beatson Institute, Glasgow, UK
- Institute of Cancer Sciences, University of Glasgow, Glasgow, UK
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5
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Long JS, Kania E, McEwan DG, Barthet VJA, Brucoli M, Ladds MJ, Nössing C, Ryan KM. ATG7 is a haploinsufficient repressor of tumor progression and promoter of metastasis. Proc Natl Acad Sci U S A 2022; 119:e2113465119. [PMID: 35867735 PMCID: PMC9282388 DOI: 10.1073/pnas.2113465119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 05/04/2022] [Indexed: 01/18/2023] Open
Abstract
The role of autophagy in cancer is complex. Both tumor-promoting and tumor-suppressive effects are reported, with tumor type, stage and specific genetic lesions dictating the role. This calls for analysis in models that best recapitulate each tumor type, from initiation to metastatic disease, to specifically understand the contribution of autophagy in each context. Here, we report the effects of deleting the essential autophagy gene Atg7 in a model of pancreatic ductal adenocarcinoma (PDAC), in which mutant KrasG12D and mutant Trp53172H are induced in adult tissue leading to metastatic PDAC. This revealed that Atg7 loss in the presence of KrasG12D/+ and Trp53172H/+ was tumor promoting, similar to previous observations in tumors driven by embryonic KrasG12D/+ and deletion of Trp53. However, Atg7 hemizygosity also enhanced tumor initiation and progression, even though this did not ablate autophagy. Moreover, despite this enhanced progression, fewer Atg7 hemizygous mice had metastases compared with animals wild type for this allele, indicating that ATG7 is a promoter of metastasis. We show, in addition, that Atg7+/- tumors have comparatively lower levels of succinate, and that cells derived from Atg7+/- tumors are also less invasive than those from Atg7+/+ tumors. This effect on invasion can be rescued by ectopic expression of Atg7 in Atg7+/- cells, without affecting the autophagic capacity of the cells, or by treatment with a cell-permeable analog of succinate. These findings therefore show that ATG7 has roles in invasion and metastasis that are not related to the role of the protein in the regulation of autophagy.
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Affiliation(s)
- Jaclyn S. Long
- Tumour Cell Death and Autophagy Laboratory, Cancer Research UK Beatson Institute, Glasgow, G61 1BD, United Kingdom
| | - Elżbieta Kania
- Tumour Cell Death and Autophagy Laboratory, Cancer Research UK Beatson Institute, Glasgow, G61 1BD, United Kingdom
| | - David G. McEwan
- Tumour Cell Death and Autophagy Laboratory, Cancer Research UK Beatson Institute, Glasgow, G61 1BD, United Kingdom
| | - Valentin J. A. Barthet
- Tumour Cell Death and Autophagy Laboratory, Cancer Research UK Beatson Institute, Glasgow, G61 1BD, United Kingdom
- Institute of Cancer Sciences, University of Glasgow, Glasgow, G61 1BD, United Kingdom
| | - Martina Brucoli
- Tumour Cell Death and Autophagy Laboratory, Cancer Research UK Beatson Institute, Glasgow, G61 1BD, United Kingdom
- Institute of Cancer Sciences, University of Glasgow, Glasgow, G61 1BD, United Kingdom
| | - Marcus J.G.W. Ladds
- Tumour Cell Death and Autophagy Laboratory, Cancer Research UK Beatson Institute, Glasgow, G61 1BD, United Kingdom
| | - Christoph Nössing
- Tumour Cell Death and Autophagy Laboratory, Cancer Research UK Beatson Institute, Glasgow, G61 1BD, United Kingdom
- Institute of Cancer Sciences, University of Glasgow, Glasgow, G61 1BD, United Kingdom
| | - Kevin M. Ryan
- Tumour Cell Death and Autophagy Laboratory, Cancer Research UK Beatson Institute, Glasgow, G61 1BD, United Kingdom
- Institute of Cancer Sciences, University of Glasgow, Glasgow, G61 1BD, United Kingdom
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6
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Barthet VJA, Mrschtik M, Kania E, McEwan DG, Croft D, O'Prey J, Long JS, Ryan KM. DRAM-4 and DRAM-5 are compensatory regulators of autophagy and cell survival in nutrient-deprived conditions. FEBS J 2022; 289:3752-3769. [PMID: 35060334 PMCID: PMC9544835 DOI: 10.1111/febs.16365] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 12/10/2021] [Accepted: 01/19/2022] [Indexed: 12/17/2022]
Abstract
Macroautophagy is a membrane-trafficking process that delivers cytoplasmic material to lysosomes for degradation. The process preserves cellular integrity by removing damaged cellular constituents and can promote cell survival by providing substrates for energy production during hiatuses of nutrient availability. The process is also highly responsive to other forms of cellular stress. For example, DNA damage can induce autophagy and this involves up-regulation of the Damage-Regulated Autophagy Modulator-1 (DRAM-1) by the tumor suppressor p53. DRAM-1 belongs to an evolutionarily conserved protein family, which has five members in humans and we describe here the initial characterization of two members of this family, which we term DRAM-4 and DRAM-5 for DRAM-Related/Associated Member 4/5. We show that the genes encoding these proteins are not regulated by p53, but instead are induced by nutrient deprivation. Similar to other DRAM family proteins, however, DRAM-4 principally localizes to endosomes and DRAM-5 to the plasma membrane and both modulate autophagy flux when over-expressed. Deletion of DRAM-4 using CRISPR/Cas-9 also increased autophagy flux, but we found that DRAM-4 and DRAM-5 undergo compensatory regulation, such that deletion of DRAM-4 does not affect autophagy flux in the absence of DRAM-5. Similarly, deletion of DRAM-4 also promotes cell survival following growth of cells in the absence of amino acids, serum, or glucose, but this effect is also impacted by the absence of DRAM-5. In summary, DRAM-4 and DRAM-5 are nutrient-responsive members of the DRAM family that exhibit interconnected roles in the regulation of autophagy and cell survival under nutrient-deprived conditions.
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Affiliation(s)
- Valentin J. A. Barthet
- Cancer Research UK Beatson InstituteGlasgowUK
- Institute of Cancer SciencesUniversity of GlasgowUK
| | | | - Elzbieta Kania
- Cancer Research UK Beatson InstituteGlasgowUK
- Institute of Cancer SciencesUniversity of GlasgowUK
| | | | - Dan Croft
- Cancer Research UK Beatson InstituteGlasgowUK
| | | | | | - Kevin M. Ryan
- Cancer Research UK Beatson InstituteGlasgowUK
- Institute of Cancer SciencesUniversity of GlasgowUK
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7
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Wu Y, Bai Y, McEwan DG, Bentley L, Aravani D, Cox RD. Palmitoylated small GTPase ARL15 is translocated within Golgi network during adipogenesis. Biol Open 2021; 10:273707. [PMID: 34779483 PMCID: PMC8689486 DOI: 10.1242/bio.058420] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 11/10/2021] [Indexed: 11/20/2022] Open
Abstract
The small GTPase ARF family member ARL15 gene locus is associated in population studies with increased risk of type 2 diabetes, lower adiponectin and higher fasting insulin levels. Previously, loss of ARL15 was shown to reduce insulin secretion in a human β-cell line and loss-of-function mutations are found in some lipodystrophy patients. We set out to understand the role of ARL15 in adipogenesis and showed that endogenous ARL15 palmitoylated and localised in the Golgi of mouse liver. Adipocyte overexpression of palmitoylation-deficient ARL15 resulted in redistribution to the cytoplasm and a mild reduction in expression of some adipogenesis-related genes. Further investigation of the localisation of ARL15 during differentiation of a human white adipocyte cell line showed that ARL15 was predominantly co-localised with a marker of the cis face of Golgi at the preadipocyte stage and then translocated to other Golgi compartments after differentiation was induced. Finally, co-immunoprecipitation and mass spectrometry identified potential interacting partners of ARL15, including the ER-localised protein ARL6IP5. Together, these results suggest a palmitoylation dependent trafficking-related role of ARL15 as a regulator of adipocyte differentiation via ARL6IP5 interaction. This article has an associated First Person interview with the first author of the paper. Summary: ARL15 (GTPase ARF family) is associated with adipose traits. ARL15 is palmitoylated, localised to Golgi in preadipocytes and translocated to other Golgi compartments during differentiation. ARL15 interacts with ER-localised ARL6IP5.
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Affiliation(s)
- Yixing Wu
- Mammalian Genetics Unit, MRC Harwell Institute, Harwell Oxford, Oxfordshire, OX11 0RD, UK
| | - Ying Bai
- Mammalian Genetics Unit, MRC Harwell Institute, Harwell Oxford, Oxfordshire, OX11 0RD, UK
| | - David G McEwan
- Division of Cell Signalling & Immunology, School of Life Sciences, University of Dundee, Dundee, UK.,Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow, G61 1BD, UK
| | - Liz Bentley
- Mammalian Genetics Unit, MRC Harwell Institute, Harwell Oxford, Oxfordshire, OX11 0RD, UK
| | - Dimitra Aravani
- Mammalian Genetics Unit, MRC Harwell Institute, Harwell Oxford, Oxfordshire, OX11 0RD, UK
| | - Roger D Cox
- Mammalian Genetics Unit, MRC Harwell Institute, Harwell Oxford, Oxfordshire, OX11 0RD, UK
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Valečka J, Camosseto V, McEwan DG, Terawaki S, Liu Z, Strock E, Almeida CR, Su B, Dikic I, Liang Y, Gatti E, Pierre P. RUFY4 exists as two translationally regulated isoforms, that localize to the mitochondrion in activated macrophages. R Soc Open Sci 2021; 8:202333. [PMID: 34295519 PMCID: PMC8278043 DOI: 10.1098/rsos.202333] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 06/22/2021] [Indexed: 05/11/2023]
Abstract
We report here that RUFY4, a newly characterized member of the 'RUN and FYVE domain-containing' family of proteins previously associated with autophagy enhancement, is highly expressed in alveolar macrophages (AM). We show that RUFY4 interacts with mitochondria upon stimulation by microbial-associated molecular patterns of AM and dendritic cells. RUFY4 interaction with mitochondria and other organelles is dependent on a previously uncharacterized OmpH domain located immediately upstream of its C-terminal FYVE domain. Further, we demonstrate that rufy4 messenger RNA can be translated from an alternative translation initiation codon, giving rise to a N-terminally truncated form of the molecule lacking most of its RUN domain and with enhanced potential for its interaction with mitochondria. Our observations point towards a role of RUFY4 in selective mitochondria clearance in activated phagocytes.
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Affiliation(s)
- Jan Valečka
- Aix Marseille Université, CNRS, INSERM, CIML, 13288 Marseille cedex 9, France
| | - Voahirana Camosseto
- Aix Marseille Université, CNRS, INSERM, CIML, 13288 Marseille cedex 9, France
| | - David G. McEwan
- Tumour Cell Death Laboratory, Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
| | - Seigo Terawaki
- Department of Pathobiochemistry, Graduate School of Medicine, Osaka City University, Osaka, Japan
| | - Zhuangzhuang Liu
- School of Laboratory Medicine, Xinxiang Medical University, Xinxiang, People's Republic of China
| | - Eva Strock
- Aix Marseille Université, CNRS, INSERM, CIML, 13288 Marseille cedex 9, France
| | - Catarina R. Almeida
- Institute for Research in Biomedicine (iBiMED) and Ilidio Pinho Foundation, Department of Medical Sciences, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Bing Su
- Shanghai Institute of Immunology, Department of Microbiology and Immunology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, People's Republic of China
| | - Ivan Dikic
- Institute of Biochemistry II, Goethe University School of Medicine, Theodor-Stern-Kai 7, 60590 Frankfurt (Main), Germany
| | - Yinming Liang
- School of Laboratory Medicine, Xinxiang Medical University, Xinxiang, People's Republic of China
| | - Evelina Gatti
- Aix Marseille Université, CNRS, INSERM, CIML, 13288 Marseille cedex 9, France
- Institute for Research in Biomedicine (iBiMED) and Ilidio Pinho Foundation, Department of Medical Sciences, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Philippe Pierre
- Aix Marseille Université, CNRS, INSERM, CIML, 13288 Marseille cedex 9, France
- Institute for Research in Biomedicine (iBiMED) and Ilidio Pinho Foundation, Department of Medical Sciences, University of Aveiro, 3810-193 Aveiro, Portugal
- Shanghai Institute of Immunology, Department of Microbiology and Immunology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, People's Republic of China
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9
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Gubas A, Karantanou C, Popovic D, Tascher G, Hoffmann ME, Platzek A, Dawe N, Dikic I, Krause DS, McEwan DG. The endolysosomal adaptor PLEKHM1 is a direct target for both mTOR and MAPK pathways. FEBS Lett 2021; 595:864-880. [PMID: 33452816 DOI: 10.1002/1873-3468.14041] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 12/23/2020] [Accepted: 12/28/2020] [Indexed: 12/21/2022]
Abstract
The lysosome is a cellular signalling hub at the point of convergence of endocytic and autophagic pathways, where the contents are degraded and recycled. Pleckstrin homology domain-containing family member 1 (PLEKHM1) acts as an adaptor to facilitate the fusion of endocytic and autophagic vesicles with the lysosome. However, it is unclear how PLEKHM1 function at the lysosome is controlled. Herein, we show that PLEKHM1 coprecipitates with, and is directly phosphorylated by, mTOR. Using a phosphospecific antibody against Ser432/S435 of PLEKHM1, we show that the same motif is a direct target for ERK2-mediated phosphorylation in a growth factor-dependent manner. This dual regulation of PLEKHM1 at a highly conserved region points to a convergence of both growth factor- and amino acid-sensing pathways, placing PLEKHM1 at a critical juncture of cellular metabolism.
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Affiliation(s)
- Andrea Gubas
- Faculty of Medicine, Institute of Biochemistry II, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Christina Karantanou
- Georg-Speyer-Haus, Institute for Tumor Biology and Experimental Medicine, Frankfurt, Germany.,Goethe University Frankfurt, Frankfurt, Germany
| | - Doris Popovic
- Faculty of Medicine, Institute of Biochemistry II, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Georg Tascher
- Faculty of Medicine, Institute of Biochemistry II, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Marina E Hoffmann
- Faculty of Medicine, Institute of Biochemistry II, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Anna Platzek
- Faculty of Medicine, Institute of Biochemistry II, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Nina Dawe
- Division of Cell Signalling & Immunology, School of Life Sciences, University of Dundee, UK
| | - Ivan Dikic
- Faculty of Medicine, Institute of Biochemistry II, Goethe University Frankfurt, Frankfurt am Main, Germany.,Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt am Main, Germany.,Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Daniela S Krause
- Georg-Speyer-Haus, Institute for Tumor Biology and Experimental Medicine, Frankfurt, Germany.,Goethe University Frankfurt, Frankfurt, Germany
| | - David G McEwan
- Division of Cell Signalling & Immunology, School of Life Sciences, University of Dundee, UK.,Cancer Research UK Beatson Institute, Garscube Estate, Glasgow, UK
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10
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Bozic M, van den Bekerom L, Milne BA, Goodman N, Roberston L, Prescott AR, Macartney TJ, Dawe N, McEwan DG. A conserved ATG2-GABARAP family interaction is critical for phagophore formation. EMBO Rep 2020; 21:e48412. [PMID: 32009292 PMCID: PMC7054675 DOI: 10.15252/embr.201948412] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 12/16/2019] [Accepted: 12/23/2019] [Indexed: 01/08/2023] Open
Abstract
The intracellular trafficking pathway, macroautophagy, is a recycling and disposal service that can be upregulated during periods of stress to maintain cellular homeostasis. An essential phase is the elongation and closure of the phagophore to seal and isolate unwanted cargo prior to lysosomal degradation. Human ATG2A and ATG2B proteins, through their interaction with WIPI proteins, are thought to be key players during phagophore elongation and closure, but little mechanistic detail is known about their function. We have identified a highly conserved motif driving the interaction between human ATG2 and GABARAP proteins that is in close proximity to the ATG2‐WIPI4 interaction site. We show that the ATG2A‐GABARAP interaction mutants are unable to form and close phagophores resulting in blocked autophagy, similar to ATG2A/ATG2B double‐knockout cells. In contrast, the ATG2A‐WIPI4 interaction mutant fully restored phagophore formation and autophagy flux, similar to wild‐type ATG2A. Taken together, we provide new mechanistic insights into the requirements for ATG2 function at the phagophore and suggest that an ATG2‐GABARAP/GABARAP‐L1 interaction is essential for phagophore formation, whereas ATG2‐WIPI4 interaction is dispensable.
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Affiliation(s)
- Mihaela Bozic
- Division of Cell Signalling & Immunology, School of Life Sciences, University of Dundee, Dundee, UK.,Edinburgh Cancer Research UK Centre, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - Luuk van den Bekerom
- Division of Cell Signalling & Immunology, School of Life Sciences, University of Dundee, Dundee, UK.,MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, UK
| | - Beth A Milne
- Division of Cell Signalling & Immunology, School of Life Sciences, University of Dundee, Dundee, UK
| | - Nicola Goodman
- Division of Cell Signalling & Immunology, School of Life Sciences, University of Dundee, Dundee, UK.,MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, UK
| | - Lisa Roberston
- Division of Cell Signalling & Immunology, School of Life Sciences, University of Dundee, Dundee, UK
| | - Alan R Prescott
- Dundee Imaging Facility, School of Life Sciences, University of Dundee, Dundee, UK
| | - Thomas J Macartney
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, UK
| | - Nina Dawe
- Division of Cell Signalling & Immunology, School of Life Sciences, University of Dundee, Dundee, UK
| | - David G McEwan
- Division of Cell Signalling & Immunology, School of Life Sciences, University of Dundee, Dundee, UK.,Cancer Research UK Beatson Institute, Glasgow, UK
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11
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Rogov VV, Stolz A, Ravichandran AC, Rios-Szwed DO, Suzuki H, Kniss A, Löhr F, Wakatsuki S, Dötsch V, Dikic I, Dobson RC, McEwan DG. Structural and functional analysis of the GABARAP interaction motif (GIM). EMBO Rep 2018; 19:19/12/e47268. [PMID: 30518659 DOI: 10.15252/embr.201847268] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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12
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Rogov VV, Stolz A, Ravichandran AC, Rios-Szwed DO, Suzuki H, Kniss A, Löhr F, Wakatsuki S, Dötsch V, Dikic I, Dobson RC, McEwan DG. Structural and functional analysis of the GABARAP interaction motif (GIM). EMBO Rep 2017; 18:1382-1396. [PMID: 28655748 PMCID: PMC5538626 DOI: 10.15252/embr.201643587] [Citation(s) in RCA: 111] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Revised: 04/28/2017] [Accepted: 05/09/2017] [Indexed: 11/09/2022] Open
Abstract
Through the canonical LC3 interaction motif (LIR), [W/F/Y]‐X1‐X2‐[I/L/V], protein complexes are recruited to autophagosomes to perform their functions as either autophagy adaptors or receptors. How these adaptors/receptors selectively interact with either LC3 or GABARAP families remains unclear. Herein, we determine the range of selectivity of 30 known core LIR motifs towards individual LC3s and GABARAPs. From these, we define a GABARAP Interaction Motif (GIM) sequence ([W/F]‐[V/I]‐X2‐V) that the adaptor protein PLEKHM1 tightly conforms to. Using biophysical and structural approaches, we show that the PLEKHM1‐LIR is indeed 11‐fold more specific for GABARAP than LC3B. Selective mutation of the X1 and X2 positions either completely abolished the interaction with all LC3 and GABARAPs or increased PLEKHM1‐GIM selectivity 20‐fold towards LC3B. Finally, we show that conversion of p62/SQSTM1, FUNDC1 and FIP200 LIRs into our newly defined GIM, by introducing two valine residues, enhances their interaction with endogenous GABARAP over LC3B. The identification of a GABARAP‐specific interaction motif will aid the identification and characterization of the expanding array of autophagy receptor and adaptor proteins and their in vivo functions.
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Affiliation(s)
- Vladimir V Rogov
- Institute of Biophysical Chemistry and Center for Biomolecular Magnetic Resonance, Goethe University, Frankfurt am Main, Germany
| | - Alexandra Stolz
- Institute of Biochemistry II, Goethe University School of Medicine, Frankfurt (Main), Germany
| | - Arvind C Ravichandran
- Biomolecular Interaction Centre, School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Diana O Rios-Szwed
- Division of Cell Signalling & Immunology, School of Life Sciences, University of Dundee, Dundee, UK
| | - Hironori Suzuki
- Biomolecular Interaction Centre, School of Biological Sciences, University of Canterbury, Christchurch, New Zealand.,Structural Biology Research Centre, Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba Ibaraki, Japan
| | - Andreas Kniss
- Institute of Biophysical Chemistry and Center for Biomolecular Magnetic Resonance, Goethe University, Frankfurt am Main, Germany
| | - Frank Löhr
- Institute of Biophysical Chemistry and Center for Biomolecular Magnetic Resonance, Goethe University, Frankfurt am Main, Germany
| | - Soichi Wakatsuki
- Structural Biology Research Centre, Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba Ibaraki, Japan.,Photon Science, SLAC National Accelerator Laboratory, Menlo Park, CA, USA.,Structural Biology (School of Medicine), Beckman Center B105, Stanford, CA, USA
| | - Volker Dötsch
- Institute of Biophysical Chemistry and Center for Biomolecular Magnetic Resonance, Goethe University, Frankfurt am Main, Germany
| | - Ivan Dikic
- Institute of Biochemistry II, Goethe University School of Medicine, Frankfurt (Main), Germany .,Buchmann Institute for Molecular Life Sciences, Goethe University, Frankfurt am Main, Germany
| | - Renwick Cj Dobson
- Biomolecular Interaction Centre, School of Biological Sciences, University of Canterbury, Christchurch, New Zealand .,Department of Biochemistry and Molecular Biology, Bio21 Institute, University of Melbourne, Parkville, Vic., Australia
| | - David G McEwan
- Institute of Biochemistry II, Goethe University School of Medicine, Frankfurt (Main), Germany .,Division of Cell Signalling & Immunology, School of Life Sciences, University of Dundee, Dundee, UK
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13
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Abstract
The endosomal system and autophagy are 2 intertwined pathways that share a number of common protein factors as well as a final destination, the lysosome. Identification of adaptor platforms that can link both pathways are of particular importance, as they serve as common nodes that can coordinate the different trafficking arms of the endolysosomal system. Using a mass spectrometry approach to identify interaction partners of active (GTP-bound) RAB7, the late endosome/lysosome GTPase, and yeast 2-hybrid screening to identify LC3/GABARAP interaction partners we discovered the multivalent adaptor protein PLEKHM1. We discovered a highly conserved LC3-interaction region (LIR) between 2 PH domains of PLEKHM1 that mediated direct binding to all LC3/GABARAP family members. Subsequent mass spectrometry analysis of PLEKHM1 precipitated from cells revealed the HOPS (homotypic fusion and protein sorting) complex as a prominent interaction partner. Functionally, depletion of PLEKHM1, HOPS, or RAB7 results in decreased autophagosome-lysosome fusion. In Plekhm1 knockout (KO) mouse embryonic fibroblasts (MEFs) we observed increased lipidated LC3B, decreased colocalization between LC3B and LAMP1 under amino acid starvation conditions and decreased autolysosome formation. Finally, PLEKHM1 binding to LC3-positive autophagosomes was also essential for selective autophagy pathways, as shown by clearance of puromycin-aggregates, in a PLEKHM1-LIR-dependent manner. Overall, we have identified PLEKHM1 as an endolysosomal adaptor platform that acts as a central hub to integrate endocytic and autophagic pathways at the lysosome.
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Affiliation(s)
- David G McEwan
- a Institute of Biochemistry II; Goethe University School of Medicine ; Frankfurt (Main) , Germany
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14
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Habisov S, Huber J, Ichimura Y, Akutsu M, Rogova N, Loehr F, McEwan DG, Johansen T, Dikic I, Doetsch V, Komatsu M, Rogov VV, Kirkin V. Structural and Functional Analysis of a Novel Interaction Motif within UFM1-activating Enzyme 5 (UBA5) Required for Binding to Ubiquitin-like Proteins and Ufmylation. J Biol Chem 2016; 291:9025-41. [PMID: 26929408 DOI: 10.1074/jbc.m116.715474] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Indexed: 12/17/2022] Open
Abstract
The covalent conjugation of ubiquitin-fold modifier 1 (UFM1) to proteins generates a signal that regulates transcription, response to cell stress, and differentiation. Ufmylation is initiated by ubiquitin-like modifier activating enzyme 5 (UBA5), which activates and transfers UFM1 to ubiquitin-fold modifier-conjugating enzyme 1 (UFC1). The details of the interaction between UFM1 and UBA5 required for UFM1 activation and its downstream transfer are however unclear. In this study, we described and characterized a combined linear LC3-interacting region/UFM1-interacting motif (LIR/UFIM) within the C terminus of UBA5. This single motif ensures that UBA5 binds both UFM1 and light chain 3/γ-aminobutyric acid receptor-associated proteins (LC3/GABARAP), two ubiquitin (Ub)-like proteins. We demonstrated that LIR/UFIM is required for the full biological activity of UBA5 and for the effective transfer of UFM1 onto UFC1 and a downstream protein substrate both in vitro and in cells. Taken together, our study provides important structural and functional insights into the interaction between UBA5 and Ub-like modifiers, improving the understanding of the biology of the ufmylation pathway.
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Affiliation(s)
- Sabrina Habisov
- From Translational Innovation Platform Oncology, Merck KGaA, Frankfurter Strasse 250, 64293 Darmstadt, Germany, the Institute of Biochemistry II, Goethe University School of Medicine, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany, the BMLS Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Riedberg Campus, Max-von-Laue-Strasse 15, 60438 Frankfurt am Main, Germany
| | - Jessica Huber
- the Institute of Biophysical Chemistry and Center for Biomolecular Magnetic Resonance, Goethe University, Max-von-Laue-Strasse 9, 60438 Frankfurt am Main, Germany
| | - Yoshinobu Ichimura
- the Department of Biochemistry, School of Medicine, Niigata University, Chuo-ku, Niigata 951-8510, Japan
| | - Masato Akutsu
- the Institute of Biochemistry II, Goethe University School of Medicine, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany, the BMLS Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Riedberg Campus, Max-von-Laue-Strasse 15, 60438 Frankfurt am Main, Germany
| | - Natalia Rogova
- the Institute of Biophysical Chemistry and Center for Biomolecular Magnetic Resonance, Goethe University, Max-von-Laue-Strasse 9, 60438 Frankfurt am Main, Germany
| | - Frank Loehr
- the Institute of Biophysical Chemistry and Center for Biomolecular Magnetic Resonance, Goethe University, Max-von-Laue-Strasse 9, 60438 Frankfurt am Main, Germany
| | - David G McEwan
- the Institute of Biochemistry II, Goethe University School of Medicine, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany, the Division of Cell Signaling and Immunology, School of Life Sciences, University of Dundee, Dundee, DD1 4HN United Kingdom, and
| | - Terje Johansen
- the Molecular Cancer Research Group, Institute of Medical Biology, University of Tromsø-The Arctic University of Norway, 9037 Tromsø, Norway
| | - Ivan Dikic
- the Institute of Biochemistry II, Goethe University School of Medicine, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany, the BMLS Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Riedberg Campus, Max-von-Laue-Strasse 15, 60438 Frankfurt am Main, Germany
| | - Volker Doetsch
- the Institute of Biophysical Chemistry and Center for Biomolecular Magnetic Resonance, Goethe University, Max-von-Laue-Strasse 9, 60438 Frankfurt am Main, Germany
| | - Masaaki Komatsu
- the Department of Biochemistry, School of Medicine, Niigata University, Chuo-ku, Niigata 951-8510, Japan
| | - Vladimir V Rogov
- the Institute of Biophysical Chemistry and Center for Biomolecular Magnetic Resonance, Goethe University, Max-von-Laue-Strasse 9, 60438 Frankfurt am Main, Germany,
| | - Vladimir Kirkin
- From Translational Innovation Platform Oncology, Merck KGaA, Frankfurter Strasse 250, 64293 Darmstadt, Germany,
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15
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Jaé N, McEwan DG, Manavski Y, Boon RA, Dimmeler S. Rab7a and Rab27b control secretion of endothelial microRNA through extracellular vesicles. FEBS Lett 2015; 589:3182-8. [PMID: 26348397 DOI: 10.1016/j.febslet.2015.08.040] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Revised: 08/26/2015] [Accepted: 08/27/2015] [Indexed: 01/08/2023]
Abstract
By transporting regulatory RNAs like microRNAs, extracellular vesicles provide a novel layer of intercellular gene regulation. However, the underlying secretory pathways and the mechanisms of cargo selection are poorly understood. Rab GTPases are central coordinators of membrane trafficking with distinct members of this family being responsible for specific transport pathways. Here we identified a vesicular export mechanism for miR-143, induced by the shear stress responsive transcription factor KLF2, and demonstrate its dependency on Rab7a/Rab27b in endothelial cells.
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Affiliation(s)
- Nicolas Jaé
- Institute for Cardiovascular Regeneration, Center of Molecular Medicine, Goethe University, Frankfurt am Main, Germany
| | - David G McEwan
- Institute of Biochemistry II, Goethe University School of Medicine, Frankfurt am Main, Germany
| | - Yosif Manavski
- Institute for Cardiovascular Regeneration, Center of Molecular Medicine, Goethe University, Frankfurt am Main, Germany
| | - Reinier A Boon
- Institute for Cardiovascular Regeneration, Center of Molecular Medicine, Goethe University, Frankfurt am Main, Germany
| | - Stefanie Dimmeler
- Institute for Cardiovascular Regeneration, Center of Molecular Medicine, Goethe University, Frankfurt am Main, Germany.
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16
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Abstract
Autophagy removes protein aggregates, damaged organelles, and intracellular pathogens from cells and helps to recycle lipids and protein building blocks. However, regulatory mechanisms of the initial, rapid response are largely unknown. In this issue of Developmental Cell, Antonioli et al. (2014) provide mechanistic insights into autophagy induction and termination by Cullin E3 ligases.
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Affiliation(s)
- David G McEwan
- Institute of Biochemistry II, Goethe University School of Medicine, Theodor-Stern-Kai 7, D-60590 Frankfurt am Main, Germany
| | - Ivan Dikic
- Institute of Biochemistry II, Goethe University School of Medicine, Theodor-Stern-Kai 7, D-60590 Frankfurt am Main, Germany; Buchmann Institute for Molecular Life Sciences, Max-von-Laue-Str. 15, Goethe University, 60438 Frankfurt am Main, Germany; University of Split, School of Medicine, Department of Immunology and Medical Genetics, Soltanska 2, 21 000 Split, Croatia.
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17
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McEwan DG, Popovic D, Gubas A, Terawaki S, Suzuki H, Stadel D, Coxon FP, Miranda de Stegmann D, Bhogaraju S, Maddi K, Kirchof A, Gatti E, Helfrich MH, Wakatsuki S, Behrends C, Pierre P, Dikic I. PLEKHM1 regulates autophagosome-lysosome fusion through HOPS complex and LC3/GABARAP proteins. Mol Cell 2014; 57:39-54. [PMID: 25498145 DOI: 10.1016/j.molcel.2014.11.006] [Citation(s) in RCA: 379] [Impact Index Per Article: 37.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Revised: 10/06/2014] [Accepted: 11/05/2014] [Indexed: 12/24/2022]
Abstract
The lysosome is the final destination for degradation of endocytic cargo, plasma membrane constituents, and intracellular components sequestered by macroautophagy. Fusion of endosomes and autophagosomes with the lysosome depends on the GTPase Rab7 and the homotypic fusion and protein sorting (HOPS) complex, but adaptor proteins that link endocytic and autophagy pathways with lysosomes are poorly characterized. Herein, we show that Pleckstrin homology domain containing protein family member 1 (PLEKHM1) directly interacts with HOPS complex and contains a LC3-interacting region (LIR) that mediates its binding to autophagosomal membranes. Depletion of PLEKHM1 blocks lysosomal degradation of endocytic (EGFR) cargo and enhances presentation of MHC class I molecules. Moreover, genetic loss of PLEKHM1 impedes autophagy flux upon mTOR inhibition and PLEKHM1 regulates clearance of protein aggregates in an autophagy- and LIR-dependent manner. PLEKHM1 is thus a multivalent endocytic adaptor involved in the lysosome fusion events controlling selective and nonselective autophagy pathways.
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Affiliation(s)
- David G McEwan
- Institute of Biochemistry II, Goethe University School of Medicine, Theodor-Stern-Kai 7, D-60590 Frankfurt (Main), Germany
| | - Doris Popovic
- Institute of Biochemistry II, Goethe University School of Medicine, Theodor-Stern-Kai 7, D-60590 Frankfurt (Main), Germany
| | - Andrea Gubas
- Institute of Biochemistry II, Goethe University School of Medicine, Theodor-Stern-Kai 7, D-60590 Frankfurt (Main), Germany
| | - Seigo Terawaki
- Centre d'Immunologie de Marseille-Luminy, Aix-Marseille Université, UM2, 13288 Marseille, France; INSERM, U1104, 13288 Marseille, France; CNRS, UMR 7280, 13288 Marseille, France
| | - Hironori Suzuki
- Biomolecular Interaction Centre, School of Biological Sciences, University of Canterbury, Christchurch 8020, New Zealand
| | - Daniela Stadel
- Institute of Biochemistry II, Goethe University School of Medicine, Theodor-Stern-Kai 7, D-60590 Frankfurt (Main), Germany
| | - Fraser P Coxon
- Musculoskeletal Research Programme, Division of Applied Medicine, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, UK
| | - Diana Miranda de Stegmann
- Musculoskeletal Research Programme, Division of Applied Medicine, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, UK
| | - Sagar Bhogaraju
- Buchmann Institute for Molecular Life Sciences, Max-von-Laue-Str. 15, Goethe University 60438 Frankfurt am Main, Germany
| | - Karthik Maddi
- Buchmann Institute for Molecular Life Sciences, Max-von-Laue-Str. 15, Goethe University 60438 Frankfurt am Main, Germany
| | - Anja Kirchof
- Institute of Biochemistry II, Goethe University School of Medicine, Theodor-Stern-Kai 7, D-60590 Frankfurt (Main), Germany
| | - Evelina Gatti
- Centre d'Immunologie de Marseille-Luminy, Aix-Marseille Université, UM2, 13288 Marseille, France; INSERM, U1104, 13288 Marseille, France; CNRS, UMR 7280, 13288 Marseille, France
| | - Miep H Helfrich
- Musculoskeletal Research Programme, Division of Applied Medicine, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, UK
| | - Soichi Wakatsuki
- Structural Biology Research Center, Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
| | - Christian Behrends
- Institute of Biochemistry II, Goethe University School of Medicine, Theodor-Stern-Kai 7, D-60590 Frankfurt (Main), Germany
| | - Philippe Pierre
- Centre d'Immunologie de Marseille-Luminy, Aix-Marseille Université, UM2, 13288 Marseille, France; INSERM, U1104, 13288 Marseille, France; CNRS, UMR 7280, 13288 Marseille, France
| | - Ivan Dikic
- Institute of Biochemistry II, Goethe University School of Medicine, Theodor-Stern-Kai 7, D-60590 Frankfurt (Main), Germany; Buchmann Institute for Molecular Life Sciences, Max-von-Laue-Str. 15, Goethe University 60438 Frankfurt am Main, Germany; University of Split, School of Medicine, Department of Immunology and Medical Genetics, Soltanska 2, 21 000 Split, Croatia.
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18
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McEwan DG, Richter B, Claudi B, Wigge C, Wild P, Farhan H, McGourty K, Coxon FP, Franz-Wachtel M, Perdu B, Akutsu M, Habermann A, Kirchof A, Helfrich MH, Odgren PR, Van Hul W, Frangakis AS, Rajalingam K, Macek B, Holden DW, Bumann D, Dikic I. PLEKHM1 regulates Salmonella-containing vacuole biogenesis and infection. Cell Host Microbe 2014; 17:58-71. [PMID: 25500191 DOI: 10.1016/j.chom.2014.11.011] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Revised: 10/21/2014] [Accepted: 11/14/2014] [Indexed: 01/13/2023]
Abstract
The host endolysosomal compartment is often manipulated by intracellular bacterial pathogens. Salmonella (Salmonella enterica serovar Typhimurium) secrete numerous effector proteins, including SifA, through a specialized type III secretion system to hijack the host endosomal system and generate the Salmonella-containing vacuole (SCV). To form this replicative niche, Salmonella targets the Rab7 GTPase to recruit host membranes through largely unknown mechanisms. We show that Pleckstrin homology domain-containing protein family member 1 (PLEKHM1), a lysosomal adaptor, is targeted by Salmonella through direct interaction with SifA. By binding the PLEKHM1 PH2 domain, Salmonella utilize a complex containing PLEKHM1, Rab7, and the HOPS tethering complex to mobilize phagolysosomal membranes to the SCV. Depletion of PLEKHM1 causes a profound defect in SCV morphology with multiple bacteria accumulating in enlarged structures and significantly dampens Salmonella proliferation in multiple cell types and mice. Thus, PLEKHM1 provides a critical interface between pathogenic infection and the host endolysosomal system.
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Affiliation(s)
- David G McEwan
- Institute of Biochemistry II, Goethe University School of Medicine, Theodor-Stern-Kai 7, D-60590 Frankfurt (Main), Germany
| | - Benjamin Richter
- Institute of Biochemistry II, Goethe University School of Medicine, Theodor-Stern-Kai 7, D-60590 Frankfurt (Main), Germany
| | - Beatrice Claudi
- Infection Biology, Biozentrum, University Basel, Klingelbergstr. 50/70, CH-4056 Basel, Switzerland
| | - Christoph Wigge
- Buchmann Institute for Molecular Life Sciences, Max-von-Laue-Str. 15, Goethe University 60438 Frankfurt am Main, Germany
| | - Philipp Wild
- Institute of Biochemistry II, Goethe University School of Medicine, Theodor-Stern-Kai 7, D-60590 Frankfurt (Main), Germany
| | - Hesso Farhan
- Infection Biology, Biozentrum, University Basel, Klingelbergstr. 50/70, CH-4056 Basel, Switzerland; Biotechnology Institute Thurga, Department of Biology, University of Konstanz, 78457 Konstanz, Germany
| | - Kieran McGourty
- Centre for Molecular Microbiology and Infection, Imperial College London, Armstrong Road, London SW7 2AZ, UK
| | - Fraser P Coxon
- Musculoskeletal Research Programme, Division of Applied Medicine, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, UK
| | - Mirita Franz-Wachtel
- Proteome Center Tübingen, Interfaculty Institute for Cell Biology, University of Tübingen, Auf der Morgenstelle 15, 72076 Tübingen, Germany
| | - Bram Perdu
- Department of Medical Genetics, University of Antwerp, Prins Boudewijnlaan 43B, 2650 Edegem, Belgium
| | - Masato Akutsu
- Infection Biology, Biozentrum, University Basel, Klingelbergstr. 50/70, CH-4056 Basel, Switzerland
| | - Anja Habermann
- Buchmann Institute for Molecular Life Sciences, Max-von-Laue-Str. 15, Goethe University 60438 Frankfurt am Main, Germany
| | - Anja Kirchof
- Institute of Biochemistry II, Goethe University School of Medicine, Theodor-Stern-Kai 7, D-60590 Frankfurt (Main), Germany
| | - Miep H Helfrich
- Musculoskeletal Research Programme, Division of Applied Medicine, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, UK
| | - Paul R Odgren
- Deptartment of Cell Biology, S7-242, University of Massachusetts Medical School, North Worcester, MA 01655, USA
| | - Wim Van Hul
- Department of Medical Genetics, University of Antwerp, Prins Boudewijnlaan 43B, 2650 Edegem, Belgium
| | - Achilleas S Frangakis
- Infection Biology, Biozentrum, University Basel, Klingelbergstr. 50/70, CH-4056 Basel, Switzerland
| | - Krishnaraj Rajalingam
- Molecular Signaling Unit, FZI, Institute for immunology, University Medical Center of the Johannes Gutenberg-University Mainz, Langenbeckstraße 1, Mainz 55131, Germany
| | - Boris Macek
- Proteome Center Tübingen, Interfaculty Institute for Cell Biology, University of Tübingen, Auf der Morgenstelle 15, 72076 Tübingen, Germany
| | - David W Holden
- Centre for Molecular Microbiology and Infection, Imperial College London, Armstrong Road, London SW7 2AZ, UK
| | - Dirk Bumann
- Infection Biology, Biozentrum, University Basel, Klingelbergstr. 50/70, CH-4056 Basel, Switzerland.
| | - Ivan Dikic
- Institute of Biochemistry II, Goethe University School of Medicine, Theodor-Stern-Kai 7, D-60590 Frankfurt (Main), Germany; Buchmann Institute for Molecular Life Sciences, Max-von-Laue-Str. 15, Goethe University 60438 Frankfurt am Main, Germany; University of Split, School of Medicine, Department of Immunology and Medical Genetics, Soltanska 2, 21 000 Split, Croatia.
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19
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Abstract
Continuous synthesis of all cellular components requires their constant turnover in order for a cell to achieve homeostasis. To this end, eukaryotic cells are endowed with two degradation pathways - the ubiquitin-proteasome system and the lysosomal pathway. The latter pathway is partly fed by autophagy, which targets intracellular material in distinct vesicles, termed autophagosomes, to the lysosome. Central to this pathway is a set of key autophagy proteins, including the ubiquitin-like modifier Atg8, that orchestrate autophagosome initiation and biogenesis. In higher eukaryotes, the Atg8 family comprises six members known as the light chain 3 (LC3) or γ-aminobutyric acid (GABA)-receptor-associated protein (GABARAP) proteins. Considerable effort during the last 15 years to decipher the molecular mechanisms that govern autophagy has significantly advanced our understanding of the functioning of this protein family. In this Cell Science at a Glance article and the accompanying poster, we present the current LC3 protein interaction network, which has been and continues to be vital for gaining insight into the regulation of autophagy.
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Affiliation(s)
- Philipp Wild
- Institute of Biochemistry II, Goethe University, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany
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Sandilands E, Serrels B, McEwan DG, Morton JP, Macagno JP, McLeod K, Stevens C, Brunton VG, Langdon WY, Vidal M, Sansom OJ, Dikic I, Wilkinson S, Frame MC. Autophagic targeting of Src promotes cancer cell survival following reduced FAK signalling. Nat Cell Biol 2011; 14:51-60. [PMID: 22138575 DOI: 10.1038/ncb2386] [Citation(s) in RCA: 139] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Accepted: 10/24/2011] [Indexed: 12/11/2022]
Abstract
Here we describe a mechanism that cancer cells use to survive when flux through the Src/FAK pathway is severely perturbed. Depletion of FAK, detachment of FAK-proficient cells or expression of non-phosphorylatable FAK proteins causes sequestration of active Src away from focal adhesions into intracellular puncta that co-stain with several autophagy regulators. Inhibition of autophagy results in restoration of active Src at peripheral adhesions, and this leads to cancer cell death. Autophagic targeting of active Src is associated with a Src-LC3B complex, and is mediated by c-Cbl. However, this is independent of c-Cbl E3 ligase activity, but is mediated by an LC3-interacting region. Thus, c-Cbl-mediated autophagic targeting of active Src can occur in cancer cells to maintain viability when flux through the integrin/Src/FAK pathway is disrupted. This exposes a previously unrecognized cancer cell vulnerability that may provide a new therapeutic opportunity.
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Affiliation(s)
- Emma Sandilands
- Edinburgh Cancer Research UK Centre, Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Edinburgh EH4 2XR, UK
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21
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Wild P, Farhan H, McEwan DG, Wagner S, Rogov VV, Brady NR, Richter B, Korac J, Waidmann O, Choudhary C, Dötsch V, Bumann D, Dikic I. Phosphorylation of the autophagy receptor optineurin restricts Salmonella growth. Science 2011; 333:228-33. [PMID: 21617041 DOI: 10.1126/science.1205405] [Citation(s) in RCA: 995] [Impact Index Per Article: 76.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Selective autophagy can be mediated via receptor molecules that link specific cargoes to the autophagosomal membranes decorated by ubiquitin-like microtubule-associated protein light chain 3 (LC3) modifiers. Although several autophagy receptors have been identified, little is known about mechanisms controlling their functions in vivo. In this work, we found that phosphorylation of an autophagy receptor, optineurin, promoted selective autophagy of ubiquitin-coated cytosolic Salmonella enterica. The protein kinase TANK binding kinase 1 (TBK1) phosphorylated optineurin on serine-177, enhancing LC3 binding affinity and autophagic clearance of cytosolic Salmonella. Conversely, ubiquitin- or LC3-binding optineurin mutants and silencing of optineurin or TBK1 impaired Salmonella autophagy, resulting in increased intracellular bacterial proliferation. We propose that phosphorylation of autophagy receptors might be a general mechanism for regulation of cargo-selective autophagy.
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Affiliation(s)
- Philipp Wild
- Frankfurt Institute for Molecular Life Sciences and Institute of Biochemistry II, Goethe University School of Medicine, Frankfurt (Main), Germany
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McEwan DG, Dikic I. The Three Musketeers of Autophagy: phosphorylation, ubiquitylation and acetylation. Trends Cell Biol 2011; 21:195-201. [PMID: 21277210 DOI: 10.1016/j.tcb.2010.12.006] [Citation(s) in RCA: 115] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2010] [Revised: 12/21/2010] [Accepted: 12/21/2010] [Indexed: 02/07/2023]
Abstract
Autophagy is a highly conserved process that allows cells, tissues and organs to survive onslaughts such as nutrient deprivation, inflammation, hypoxia and other stresses. The core component proteins that regulate autophagy are well known, and the formation of a double-membrane structure that encompasses cytosolic cargo, including protein aggregates and organelles, has been intensively studied. However, less is known about the inputs that specifically alter recruitment of these components and how post-translational modifications can influence autophagy flux, or the rate at which autophagy substrates are turned over. We propose that three types of post-translational modifications - phosphorylation, ubiquitylation and acetylation - are crucial for autophagy induction, regulation and fine-tuning, and are influenced by a variety of stimuli. Understanding these novel mechanisms of autophagy regulation will give us deeper insights into this process and potentially open up therapeutic avenues.
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Affiliation(s)
- David G McEwan
- Frankfurt Institute for Molecular Life Sciences and Institute of Biochemistry II, Goethe University, Theodor-Stern-Kai 7, Frankfurt am Main D-60590, Germany.
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Novak I, Kirkin V, McEwan DG, Zhang J, Wild P, Rozenknop A, Rogov V, Löhr F, Popovic D, Occhipinti A, Reichert AS, Terzic J, Dötsch V, Ney PA, Dikic I. Nix is a selective autophagy receptor for mitochondrial clearance. EMBO Rep 2009; 11:45-51. [PMID: 20010802 DOI: 10.1038/embor.2009.256] [Citation(s) in RCA: 925] [Impact Index Per Article: 61.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2009] [Revised: 11/02/2009] [Accepted: 11/04/2009] [Indexed: 02/07/2023] Open
Abstract
Autophagy is the cellular homeostatic pathway that delivers large cytosolic materials for degradation in the lysosome. Recent evidence indicates that autophagy mediates selective removal of protein aggregates, organelles and microbes in cells. Yet, the specificity in targeting a particular substrate to the autophagy pathway remains poorly understood. Here, we show that the mitochondrial protein Nix is a selective autophagy receptor by binding to LC3/GABARAP proteins, ubiquitin-like modifiers that are required for the growth of autophagosomal membranes. In cultured cells, Nix recruits GABARAP-L1 to damaged mitochondria through its amino-terminal LC3-interacting region. Furthermore, ablation of the Nix:LC3/GABARAP interaction retards mitochondrial clearance in maturing murine reticulocytes. Thus, Nix functions as an autophagy receptor, which mediates mitochondrial clearance after mitochondrial damage and during erythrocyte differentiation.
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Affiliation(s)
- Ivana Novak
- Mediterranean Institute for Life Sciences, Mestrovicevo setaliste bb, HR-21000 Split, Croatia
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Kirkin V, Lamark T, Sou YS, Bjørkøy G, Nunn JL, Bruun JA, Shvets E, McEwan DG, Clausen TH, Wild P, Bilusic I, Theurillat JP, Øvervatn A, Ishii T, Elazar Z, Komatsu M, Dikic I, Johansen T. A role for NBR1 in autophagosomal degradation of ubiquitinated substrates. Mol Cell 2009; 33:505-16. [PMID: 19250911 DOI: 10.1016/j.molcel.2009.01.020] [Citation(s) in RCA: 847] [Impact Index Per Article: 56.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2008] [Revised: 10/17/2008] [Accepted: 01/16/2009] [Indexed: 02/08/2023]
Abstract
Autophagy is a catabolic process where cytosolic cellular components are delivered to the lysosome for degradation. Recent studies have indicated the existence of specific receptors, such as p62, which link ubiquitinated targets to autophagosomal degradation pathways. Here we show that NBR1 (neighbor of BRCA1 gene 1) is an autophagy receptor containing LC3- and ubiquitin (Ub)-binding domains. NBR1 is recruited to Ub-positive protein aggregates and degraded by autophagy depending on an LC3-interacting region (LIR) and LC3 family modifiers. Although NBR1 and p62 interact and form oligomers, they can function independently, as shown by autophagosomal clearance of NBR1 in p62-deficient cells. NBR1 was localized to Ub-positive inclusions in patients with liver dysfunction, and depletion of NBR1 abolished the formation of Ub-positive p62 bodies upon puromycin treatment of cells. We propose that NBR1 and p62 act as receptors for selective autophagosomal degradation of ubiquitinated targets.
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Affiliation(s)
- Vladimir Kirkin
- Institute of Biochemistry II, Goethe University, Frankfurt (Main), Germany
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McEwan DG, Brunton VG, Baillie GS, Leslie NR, Houslay MD, Frame MC. Chemoresistant KM12C colon cancer cells are addicted to low cyclic AMP levels in a phosphodiesterase 4-regulated compartment via effects on phosphoinositide 3-kinase. Cancer Res 2007; 67:5248-57. [PMID: 17545604 DOI: 10.1158/0008-5472.can-07-0097] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
One of the major problems in treating colon cancer is chemoresistance to cytotoxic chemotherapeutic agents. There is therefore a need to devise new strategies to inhibit colon cancer cell growth and survival. Here, we show that a combination of low doses of the adenylyl cyclase activator forskolin together with the specific cyclic AMP (cAMP) phosphodiesterase-4 (PDE4) inhibitor rolipram, but not the cAMP phosphodiesterase-3 (PDE3) inhibitor cilostamide, causes profound growth arrest of chemoresistant KM12C colon cancer cells. Low-dose forskolin causes KM12C cells to exit the cell cycle in G1 by inducing p27(Kip1) and primes cells for apoptosis on addition of rolipram. The effect of the low-dose forskolin/rolipram combination is mediated by displacement of the phosphatidylinositol 3,4,5-trisphosphate/phosphoinositide 3-kinase signaling module from the plasma membrane and suppression of the Akt/protein kinase-B oncogene pathway, to which KM12C cells are addicted for growth. The cAMP and phosphoinositide 3-kinase pathways form a critical intersection in this response, and reexpression of the tumor suppressor lipid phosphatase, phosphatase and tensin homologue, which is commonly lost or mutated in colon cancer, sensitizes KM12C cells to growth inhibition by challenge with low-dose forskolin. Certain chemoresistant colon cancer cells are therefore exquisitely sensitive to subtle elevation of cAMP by a synergistic low-dose adenylyl cyclase activator/PDE4 inhibitor combination. Indeed, these cells are addicted to maintenance of low cAMP concentrations in a compartment that is regulated by PDE4. Well-tolerated doses of PDE4 inhibitors that are already in clinical development for other therapeutic indications may provide an exciting new strategy for the treatment of colon cancer.
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Affiliation(s)
- David G McEwan
- The Beatson Institute for Cancer Research, Cancer Research UK Beatson Laboratories, Glasgow, United Kingdom
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26
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Bolger GB, Peden AH, Steele MR, MacKenzie C, McEwan DG, Wallace DA, Huston E, Baillie GS, Houslay MD. Attenuation of the activity of the cAMP-specific phosphodiesterase PDE4A5 by interaction with the immunophilin XAP2. J Biol Chem 2003; 278:33351-63. [PMID: 12810716 DOI: 10.1074/jbc.m303269200] [Citation(s) in RCA: 135] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The cyclic AMP-specific phosphodiesterase (PDE4) isoform PDE4A5 interacted with the immunophilin XAP2 in a yeast two-hybrid assay. The interaction was confirmed in biochemical pull-down analyses. The interaction was specific, in that PDE4A5 did not interact with the closely related immunophilins AIPL1, FKBP51, or FKBP52. XAP2 also did not interact with other PDE4A isoforms or typical isoforms from the three other PDE4 subfamilies. Functionally, XAP2 reversibly inhibited the enzymatic activity of PDE4A5, increased the sensitivity of PDE4A5 to inhibition by the prototypical PDE4 inhibitor 4-[3-(cyclopentyloxy)-4-methoxyphenyl]-2-pyrrolidinone (rolipram) and attenuated the ability of cAMP-dependent protein kinase to phosphorylate PDE4A5 in intact cells. XAP2 maximally inhibited PDE4A5 by approximately 60%, with an IC50 of 120 nm, and reduced the IC50 for rolipram from 390 nm to 70-90 nm. Co-expression of XAP2 and PDE4A5 in COS7 cells showed that they could be co-immunoprecipitated and also reduced both the enzymatic activity of PDE4A5 and its IC50 for rolipram. Native XAP2 and PDE4A5 could be co-immunoprecipitated from the brain. The isolated COOH-terminal half of XAP2 (amino acids 170-330), containing its tetratricopeptide repeat domain, but not the isolated NH2-terminal half (amino acids 1-169), containing the immunophilin homology region, similarly reduced PDE4A5 activity and its IC50 for rolipram. Mutation of Arg271 to alanine, in the XAP2 tetratricopeptide repeat region, attenuated its ability to both interact with PDE4A5 in two-hybrid assays and to inhibit PDE4A5 activity. Either the deletion of a specific portion of the unique amino-terminal region or specific mutations in the regulatory UCR2 domain of PDE4A5 attenuated its ability be inhibited by XAP2. We suggest that XAP2 functionally interacts with PDE4A5 in cells.
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Affiliation(s)
- Graeme B Bolger
- Veterans Affairs Medical Center, Huntsman Cancer Institute, Department of Medicine, Division of Oncology, University of Utah Health Sciences Center, Salt Lake City, Utah 84148, USA.
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