1
|
Pfitzner AK, Zivkovic H, Bernat-Silvestre C, West M, Peltier T, Humbert F, Odorizzi G, Roux A. Vps60 initiates alternative ESCRT-III filaments. J Cell Biol 2023; 222:e202206028. [PMID: 37768378 PMCID: PMC10538557 DOI: 10.1083/jcb.202206028] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 03/08/2023] [Accepted: 06/12/2023] [Indexed: 09/29/2023] Open
Abstract
Endosomal sorting complex required for transport-III (ESCRT-III) participates in essential cellular functions, from cell division to endosome maturation. The remarkable increase of its subunit diversity through evolution may have enabled the acquisition of novel functions. Here, we characterize a novel ESCRT-III copolymer initiated by Vps60. Membrane-bound Vps60 polymers recruit Vps2, Vps24, Did2, and Ist1, as previously shown for Snf7. Snf7- and Vps60-based filaments can coexist on membranes without interacting as their polymerization and recruitment of downstream subunits remain spatially and biochemically separated. In fibroblasts, Vps60/CHMP5 and Snf7/CHMP4 are both recruited during endosomal functions and cytokinesis, but their localization is segregated and their recruitment dynamics are different. Contrary to Snf7/CHMP4, Vps60/CHMP5 is not recruited during nuclear envelope reformation. Taken together, our results show that Vps60 and Snf7 form functionally distinct ESCRT-III polymers, supporting the notion that diversification of ESCRT-III subunits through evolution is linked to the acquisition of new cellular functions.
Collapse
Affiliation(s)
| | - Henry Zivkovic
- Department of Biochemistry, University of Geneva, Geneva, Switzerland
| | | | - Matt West
- Department of Molecular Cellular and Developmental Biology, University of Colorado, Boulder, CO, USA
| | - Tanner Peltier
- Department of Molecular Cellular and Developmental Biology, University of Colorado, Boulder, CO, USA
| | - Frédéric Humbert
- Department of Biochemistry, University of Geneva, Geneva, Switzerland
| | - Greg Odorizzi
- Department of Molecular Cellular and Developmental Biology, University of Colorado, Boulder, CO, USA
| | - Aurélien Roux
- Department of Biochemistry, University of Geneva, Geneva, Switzerland
- National Center of Competence in Research in Chemical Biology, University of Geneva, Geneva, Switzerland
| |
Collapse
|
2
|
Abstract
Ubiquitination is a posttranslational modification that regulates a multitude of cellular functions. Pathogens, such as bacteria and viruses, have evolved sophisticated mechanisms that evade or counteract ubiquitin-dependent host responses, or even exploit the ubiquitin system to their own advantage. This is largely done by numerous pathogen virulence factors that encode E3 ligases and deubiquitinases, which are often used as weapons in pathogen-host cell interactions. Moreover, upon pathogen attack, host cellular signaling networks undergo major ubiquitin-dependent changes to protect the host cell, including coordination of innate immunity, remodeling of cellular organelles, reorganization of the cytoskeleton, and reprogramming of metabolic pathways to restrict growth of the pathogen. Here we provide mechanistic insights into ubiquitin regulation of host-pathogen interactions and how it affects bacterial and viral pathogenesis and the organization and response of the host cell.
Collapse
Affiliation(s)
- Rukmini Mukherjee
- Institute of Biochemistry II, Faculty of Medicine, Goethe University, Frankfurt, Germany; .,Buchmann Institute for Molecular Life Sciences, Goethe University, Frankfurt, Germany.,Max Planck Institute of Biophysics, Frankfurt, Germany
| | - Ivan Dikic
- Institute of Biochemistry II, Faculty of Medicine, Goethe University, Frankfurt, Germany; .,Buchmann Institute for Molecular Life Sciences, Goethe University, Frankfurt, Germany.,Max Planck Institute of Biophysics, Frankfurt, Germany.,Fraunhofer Institute for Molecular Biology and Applied Ecology (IME), Branch Translational Medicine and Pharmacology, Frankfurt, Germany
| |
Collapse
|
3
|
Mathieu J, Michel-Hissier P, Boucherit V, Huynh JR. The deubiquitinase USP8 targets ESCRT-III to promote incomplete cell division. Science 2022; 376:818-823. [PMID: 35587967 DOI: 10.1126/science.abg2653] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
In many vertebrate and invertebrate organisms, gametes develop within groups of interconnected cells called germline cysts formed by several rounds of incomplete divisions. We found that loss of the deubiquitinase USP8 gene in Drosophila can transform incomplete divisions of germline cells into complete divisions. Conversely, overexpression of USP8 in germline stem cells is sufficient for the reverse transformation from complete to incomplete cytokinesis. The ESCRT-III proteins CHMP2B and Shrub/CHMP4 are targets of USP8 deubiquitinating activity. In Usp8 mutant sister cells, ectopic recruitment of ESCRT proteins at intercellular bridges causes cysts to break apart. A Shrub/CHMP4 variant that cannot be ubiquitinated does not localize at abscission bridges and cannot complete abscission. Our results uncover ubiquitination of ESCRT-III as a major switch between two types of cell division.
Collapse
Affiliation(s)
- Juliette Mathieu
- Center for Interdisciplinary Research in Biology, Collège de France, PSL Research University, CNRS, Inserm, Paris, France
| | - Pascale Michel-Hissier
- Center for Interdisciplinary Research in Biology, Collège de France, PSL Research University, CNRS, Inserm, Paris, France
| | - Virginie Boucherit
- Center for Interdisciplinary Research in Biology, Collège de France, PSL Research University, CNRS, Inserm, Paris, France
| | - Jean-René Huynh
- Center for Interdisciplinary Research in Biology, Collège de France, PSL Research University, CNRS, Inserm, Paris, France
| |
Collapse
|
4
|
Buysse D, West M, Leih M, Odorizzi G. Bro1 binds the Vps20 subunit of ESCRT-III and promotes ESCRT-III regulation by Doa4. Traffic 2022; 23:109-119. [PMID: 34908216 PMCID: PMC8792227 DOI: 10.1111/tra.12828] [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: 06/26/2021] [Revised: 11/19/2021] [Accepted: 12/09/2021] [Indexed: 02/03/2023]
Abstract
The budding of intralumenal vesicles (ILVs) at endosomes requires membrane scission by the ESCRT-III complex. This step is negatively regulated in yeast by Doa4, the ubiquitin hydrolase that deubiquitinates transmembrane proteins sorted as cargoes into ILVs. Doa4 acts non-enzymatically to inhibit ESCRT-III membrane scission activity by directly binding the Snf7 subunit of ESCRT-III. This interaction inhibits the remodeling/disassembly of Snf7 polymers required for the ILV membrane scission reaction. Thus, Doa4 is thought to have a structural role that delays ILV budding while it also functions enzymatically to deubiquitinate ILV cargoes. In this study, we show that Doa4 binding to Snf7 in vivo is antagonized by another ESCRT-III subunit, Vps20. Doa4 is restricted from interacting with Snf7 in yeast expressing a mutant Vps20 allele that constitutively binds Doa4. This inhibitory effect of Vps20 is suppressed by overexpression of another ESCRT-III-associated protein, Bro1. We show that Bro1 binds directly to Vps20, suggesting that Bro1 has a central role in relieving the antagonistic relationship that Vps20 has toward Doa4.
Collapse
Affiliation(s)
- Dalton Buysse
- Department of Molecular Cellular and Developmental Biology, University of Colorado, Boulder, CO 80309, USA
| | - Matt West
- Department of Molecular Cellular and Developmental Biology, University of Colorado, Boulder, CO 80309, USA
| | - Mitchell Leih
- Department of Molecular Cellular and Developmental Biology, University of Colorado, Boulder, CO 80309, USA
| | - Greg Odorizzi
- Department of Molecular Cellular and Developmental Biology, University of Colorado, Boulder, CO 80309, USA,Author for correspondence ()
| |
Collapse
|
5
|
Wilson ZN, Buysse D, West M, Ahrens D, Odorizzi G. Vacuolar H+-ATPase dysfunction rescues intralumenal vesicle cargo sorting in yeast lacking PI(3,5)P2 or Doa4. J Cell Sci 2021; 134:jcs258459. [PMID: 34342352 PMCID: PMC8353521 DOI: 10.1242/jcs.258459] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 06/25/2021] [Indexed: 12/19/2022] Open
Abstract
Endosomes undergo a maturation process highlighted by a reduction in lumenal pH, a conversion of surface markers that prime endosome-lysosome fusion and the sequestration of ubiquitylated transmembrane protein cargos within intralumenal vesicles (ILVs). We investigated ILV cargo sorting in mutant strains of the budding yeast Saccharomyces cerevisiae that are deficient for either the lysosomal/vacuolar signaling lipid PI(3,5)P2 or the Doa4 ubiquitin hydrolase that deubiquitylates ILV cargos. Disruption of PI(3,5)P2 synthesis or Doa4 function causes a defect in sorting of a subset of ILV cargos. We show that these cargo-sorting defects are suppressed by mutations that disrupt Vph1, a subunit of vacuolar H+-ATPase (V-ATPase) complexes that acidify late endosomes and vacuoles. We further show that Vph1 dysfunction increases endosome abundance, and disrupts vacuolar localization of Ypt7 and Vps41, two crucial mediators of endosome-vacuole fusion. Because V-ATPase inhibition attenuates this fusion and rescues the ILV cargo-sorting defects in yeast that lack PI(3,5)P2 or Doa4 activity, our results suggest that the V-ATPase has a role in coordinating ILV cargo sorting with the membrane fusion machinery. This article has an associated First Person interview with the first author of the paper.
Collapse
Affiliation(s)
| | | | | | | | - Greg Odorizzi
- Department of Molecular Cellular and Developmental Biology, University of Colorado, Boulder, CO 80309, USA
| |
Collapse
|
6
|
Tseng CC, Dean S, Davies BA, Azmi IF, Pashkova N, Payne JA, Staffenhagen J, West M, Piper RC, Odorizzi G, Katzmann DJ. Bro1 stimulates Vps4 to promote intralumenal vesicle formation during multivesicular body biogenesis. J Cell Biol 2021; 220:212434. [PMID: 34160559 PMCID: PMC8240856 DOI: 10.1083/jcb.202102070] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 05/18/2021] [Accepted: 05/23/2021] [Indexed: 01/20/2023] Open
Abstract
Endosomal sorting complexes required for transport (ESCRT-0, -I, -II, -III) execute cargo sorting and intralumenal vesicle (ILV) formation during conversion of endosomes to multivesicular bodies (MVBs). The AAA-ATPase Vps4 regulates the ESCRT-III polymer to facilitate membrane remodeling and ILV scission during MVB biogenesis. Here, we show that the conserved V domain of ESCRT-associated protein Bro1 (the yeast homologue of mammalian proteins ALIX and HD-PTP) directly stimulates Vps4. This activity is required for MVB cargo sorting. Furthermore, the Bro1 V domain alone supports Vps4/ESCRT–driven ILV formation in vivo without efficient MVB cargo sorting. These results reveal a novel activity of the V domains of Bro1 homologues in licensing ESCRT-III–dependent ILV formation and suggest a role in coordinating cargo sorting with membrane remodeling during MVB sorting. Moreover, ubiquitin binding enhances V domain stimulation of Vps4 to promote ILV formation via the Bro1–Vps4–ESCRT-III axis, uncovering a novel role for ubiquitin during MVB biogenesis in addition to facilitating cargo recognition.
Collapse
Affiliation(s)
- Chun-Che Tseng
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN.,Biochemistry and Molecular Biology Graduate Program, Mayo Clinic Graduate School of Biomedical Sciences, Mayo Clinic, Rochester, MN
| | - Shirley Dean
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN.,Biochemistry and Molecular Biology Graduate Program, Mayo Clinic Graduate School of Biomedical Sciences, Mayo Clinic, Rochester, MN
| | - Brian A Davies
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN
| | - Ishara F Azmi
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN.,Biochemistry and Molecular Biology Graduate Program, Mayo Clinic Graduate School of Biomedical Sciences, Mayo Clinic, Rochester, MN
| | - Natalya Pashkova
- Department of Molecular Physiology and Biophysics, Carver College of Medicine, University of Iowa, Iowa City, IA
| | - Johanna A Payne
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN
| | | | - Matt West
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, CO
| | - Robert C Piper
- Department of Molecular Physiology and Biophysics, Carver College of Medicine, University of Iowa, Iowa City, IA
| | - Greg Odorizzi
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, CO
| | - David J Katzmann
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN.,Biochemistry and Molecular Biology Graduate Program, Mayo Clinic Graduate School of Biomedical Sciences, Mayo Clinic, Rochester, MN
| |
Collapse
|
7
|
Meusser B, Purfuerst B, Luft FC. HIV-1 Gag release from yeast reveals ESCRT interaction with the Gag N-terminal protein region. J Biol Chem 2020; 295:17950-17972. [PMID: 32994219 PMCID: PMC7939435 DOI: 10.1074/jbc.ra120.014710] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 09/25/2020] [Indexed: 11/30/2022] Open
Abstract
The HIV-1 protein Gag assembles at the plasma membrane and drives virion budding, assisted by the cellular endosomal complex required for transport (ESCRT) proteins. Two ESCRT proteins, TSG101 and ALIX, bind to the Gag C-terminal p6 peptide. TSG101 binding is important for efficient HIV-1 release, but how ESCRTs contribute to the budding process and how their activity is coordinated with Gag assembly is poorly understood. Yeast, allowing genetic manipulation that is not easily available in human cells, has been used to characterize the cellular ESCRT function. Previous work reported Gag budding from yeast spheroplasts, but Gag release was ESCRT-independent. We developed a yeast model for ESCRT-dependent Gag release. We combined yeast genetics and Gag mutational analysis with Gag-ESCRT binding studies and the characterization of Gag-plasma membrane binding and Gag release. With our system, we identified a previously unknown interaction between ESCRT proteins and the Gag N-terminal protein region. Mutations in the Gag-plasma membrane-binding matrix domain that reduced Gag-ESCRT binding increased Gag-plasma membrane binding and Gag release. ESCRT knockout mutants showed that the release enhancement was an ESCRT-dependent effect. Similarly, matrix mutation enhanced Gag release from human HEK293 cells. Release enhancement partly depended on ALIX binding to p6, although binding site mutation did not impair WT Gag release. Accordingly, the relative affinity for matrix compared with p6 in GST-pulldown experiments was higher for ALIX than for TSG101. We suggest that a transient matrix-ESCRT interaction is replaced when Gag binds to the plasma membrane. This step may activate ESCRT proteins and thereby coordinate ESCRT function with virion assembly.
Collapse
Affiliation(s)
- Birgit Meusser
- Charité Medical Faculty, Berlin, Germany; Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
| | | | - Friedrich C Luft
- Charité Medical Faculty, Berlin, Germany; Max-Delbrück-Center for Molecular Medicine, Berlin, Germany; Experimental and Clinical Research Center, Berlin, Germany.
| |
Collapse
|
8
|
Buysse D, Pfitzner AK, West M, Roux A, Odorizzi G. The ubiquitin hydrolase Doa4 directly binds Snf7 to inhibit recruitment of ESCRT-III remodeling factors in S. cerevisiae. J Cell Sci 2020; 133:jcs.241455. [PMID: 32184262 DOI: 10.1242/jcs.241455] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 03/02/2020] [Indexed: 12/21/2022] Open
Abstract
The ESCRT-III protein complex executes reverse-topology membrane scission. The scission mechanism is unclear but is linked to remodeling of ESCRT-III complexes at the membrane surface. At endosomes, ESCRT-III mediates the budding of intralumenal vesicles (ILVs). In Saccharomyces cerevisiae, ESCRT-III activity at endosomes is regulated through an unknown mechanism by Doa4, an ubiquitin hydrolase that deubiquitylates transmembrane proteins sorted into ILVs. We report that the non-catalytic N-terminus of Doa4 binds Snf7, the predominant ESCRT-III subunit. Through this interaction, Doa4 overexpression alters Snf7 assembly status and inhibits ILV membrane scission. In vitro, the Doa4 N-terminus inhibits association of Snf7 with Vps2, which functions with Vps24 to arrest Snf7 polymerization and remodel Snf7 polymer structure. In vivo, Doa4 overexpression inhibits Snf7 interaction with Vps2 and also with the ATPase Vps4, which is recruited by Vps2 and Vps24 to remodel ESCRT-III complexes by catalyzing subunit turnover. Our data suggest a mechanism by which the deubiquitylation machinery regulates ILV biogenesis by interfering with ESCRT-III remodeling.
Collapse
Affiliation(s)
- Dalton Buysse
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, CO 80309, USA
| | | | - Matt West
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, CO 80309, USA
| | - Aurélien Roux
- Department of Biochemistry, University of Geneva, Geneva CH-1211, Switzerland.,Swiss National Centre for Competence in Research Program Chemical Biology, Geneva CH-1211, Switzerland
| | - Greg Odorizzi
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, CO 80309, USA
| |
Collapse
|
9
|
Ubiquitin-specific protease 8 (USP8/UBPy): a prototypic multidomain deubiquitinating enzyme with pleiotropic functions. Biochem Soc Trans 2020; 47:1867-1879. [PMID: 31845722 PMCID: PMC6925526 DOI: 10.1042/bst20190527] [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: 10/04/2019] [Revised: 11/29/2019] [Accepted: 12/02/2019] [Indexed: 01/07/2023]
Abstract
Protein modification by ubiquitin is one of the most versatile posttranslational regulations and counteracted by almost 100 deubiquitinating enzymes (DUBs). USP8 was originally identified as a growth regulated ubiquitin-specific protease and is like many other DUBs characterized by its multidomain architecture. Besides the catalytic domain, specific protein-protein interaction modules were characterized which contribute to USP8 substrate recruitment, regulation and targeting to distinct protein complexes. Studies in mice and humans impressively showed the physiological relevance and non-redundant function of USP8 within the context of the whole organism. USP8 knockout (KO) mice exhibit early embryonic lethality while induced deletion in adult animals rapidly causes lethal liver failure. Furthermore, T-cell specific ablation disturbs T-cell development and function resulting in fatal autoimmune inflammatory bowel disease. In human patients, somatic mutations in USP8 were identified as the underlying cause of adrenocorticotropic hormone (ACTH) releasing pituitary adenomas causing Cushing's disease (CD). Here we provide an overview of the versatile molecular, cellular and pathology associated function and regulation of USP8 which appears to depend on specific protein binding partners, substrates and the cellular context.
Collapse
|
10
|
Ahmed I, Akram Z, Iqbal HMN, Munn AL. The regulation of Endosomal Sorting Complex Required for Transport and accessory proteins in multivesicular body sorting and enveloped viral budding - An overview. Int J Biol Macromol 2019; 127:1-11. [PMID: 30615963 DOI: 10.1016/j.ijbiomac.2019.01.015] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 01/03/2019] [Accepted: 01/03/2019] [Indexed: 02/07/2023]
Abstract
ESCRT (Endosomal Sorting Complex Required for Transport) machinery drives different cellular processes such as endosomal sorting, organelle biogenesis, vesicular trafficking, maintenance of plasma membrane integrity, membrane fission during cytokinesis and enveloped virus budding. The normal cycle of assembly and disassembly of some ESCRT complexes at the membrane requires the AAA-ATPase vacuolar protein sorting 4 (Vps4p). A number of ESCRT proteins are hijacked by clinically significant enveloped viruses including Ebola, and Human Immunodeficiency Virus (HIV) to enable enveloped virus budding and Vps4p provides energy for the disassembly/recycling of these ESCRT proteins. Several years ago, the failure of the terminal budding process of HIV following Vps4 protein inhibition was published; although at that time a detailed understanding of the molecular players was missing. However, later it was acknowledged that the ESCRT machinery has a role in enveloped virus budding from cells due to its role in the multivesicular body (MVB) sorting pathway. The MVB sorting pathway facilitates several cellular activities in uninfected cells, such as the down-regulation of signaling through cell surface receptors as well as the process of viral budding from infected host cells. In this review, we focus on summarising the functional organisation of ESCRT proteins at the membrane and the role of ESCRT machinery and Vps4p during MVB sorting and enveloped viral budding.
Collapse
Affiliation(s)
- Ishtiaq Ahmed
- School of Medical Science, Menzies Health Institute Queensland, Griffith University (Gold Coast campus), Parklands Drive, Southport, QLD 4222, Australia.
| | - Zain Akram
- School of Medical Science, Menzies Health Institute Queensland, Griffith University (Gold Coast campus), Parklands Drive, Southport, QLD 4222, Australia
| | - Hafiz M N Iqbal
- Tecnologico de Monterrey, School of Engineering and Sciences, Campus Monterrey, Ave. Eugenio Garza Sada 2501, Monterrey, N. L. CP 64849, Mexico
| | - Alan L Munn
- School of Medical Science, Menzies Health Institute Queensland, Griffith University (Gold Coast campus), Parklands Drive, Southport, QLD 4222, Australia.
| |
Collapse
|
11
|
ESCRT-mediated sorting and intralumenal vesicle concatenation in plants. Biochem Soc Trans 2018; 46:537-545. [PMID: 29666213 DOI: 10.1042/bst20170439] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2018] [Revised: 03/09/2018] [Accepted: 03/16/2018] [Indexed: 12/16/2022]
Abstract
The degradation of plasma membrane and other membrane-associated proteins require their sorting at endosomes for delivery to the vacuole. Through the endocytic pathway, ubiquitinated membrane proteins (cargo) are delivered to endosomes where the ESCRT (endosomal sorting complex required for transport) machinery sorts them into intralumenal vesicles for degradation. Plants contain both conserved and plant-specific ESCRT subunits. In this review, I discuss the role of characterized plant ESCRT components, the evolutionary diversification of the plant ESCRT machinery, and a recent study showing that endosomal intralumenal vesicles form in clusters of concatenated vesicle buds by temporally uncoupling membrane constriction from membrane fission.
Collapse
|
12
|
Frankel EB, Audhya A. ESCRT-dependent cargo sorting at multivesicular endosomes. Semin Cell Dev Biol 2018; 74:4-10. [PMID: 28797838 PMCID: PMC5803488 DOI: 10.1016/j.semcdb.2017.08.020] [Citation(s) in RCA: 97] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Revised: 08/02/2017] [Accepted: 08/05/2017] [Indexed: 01/26/2023]
Abstract
The endosomal sorting complex required for transport (ESCRT) machinery is composed of five multi-subunit protein complexes, which act cooperatively at specialized endosomes to facilitate the movement of specific cargoes from the limiting membrane into vesicles that bud into the endosome lumen. Over the past decade, numerous proteins, lipids, and RNAs have been shown to be incorporated into intralumenal vesicles (ILVs), but the mechanisms by which these unique cargoes are captured are only now becoming better understood. Here, we discuss the potential roles that the ESCRT machinery plays during cargo sorting at multivesicular endosomes (MVEs).
Collapse
Affiliation(s)
- E B Frankel
- Department of Biomolecular Chemistry, University of Wisconsin-Madison School of Medicine and Public Health, 440 Henry Mall, Madison, WI, 53706, USA
| | - Anjon Audhya
- Department of Biomolecular Chemistry, University of Wisconsin-Madison School of Medicine and Public Health, 440 Henry Mall, Madison, WI, 53706, USA.
| |
Collapse
|
13
|
Buono RA, Leier A, Paez-Valencia J, Pennington J, Goodman K, Miller N, Ahlquist P, Marquez-Lago TT, Otegui MS. ESCRT-mediated vesicle concatenation in plant endosomes. J Cell Biol 2017; 216:2167-2177. [PMID: 28592443 PMCID: PMC5496621 DOI: 10.1083/jcb.201612040] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 04/06/2017] [Accepted: 05/01/2017] [Indexed: 11/23/2022] Open
Abstract
ESCRT proteins play essential functions by remodeling cellular membranes. Buono et al. report on a novel ESCRT-dependent mechanism in plant endosomes that leads to sequential concatenation of vesicle buds by temporally uncoupling membrane constriction from membrane fission. During this process, ESCRT-III proteins remain inside endosomes after intralumenal vesicle release. Ubiquitinated plasma membrane proteins (cargo) are delivered to endosomes and sorted by endosomal sorting complex required for transport (ESCRT) machinery into endosome intralumenal vesicles (ILVs) for degradation. In contrast to the current model that postulates that ILVs form individually from inward budding of the endosomal limiting membrane, plant ILVs form as networks of concatenated vesicle buds by a novel vesiculation mechanism. We ran computational simulations based on experimentally derived diffusion coefficients of an ESCRT cargo protein and electron tomograms of Arabidopsis thaliana endosomes to measure cargo escape from budding ILVs. We found that 50% of the ESCRT cargo would escape from a single budding profile in 5–20 ms and from three concatenated ILVs in 80–200 ms. These short cargo escape times predict the need for strong diffusion barriers in ILVs. Consistent with a potential role as a diffusion barrier, we find that the ESCRT-III protein SNF7 remains associated with ILVs and is delivered to the vacuole for degradation.
Collapse
Affiliation(s)
- Rafael Andrade Buono
- Department of Botany, University of Wisconsin-Madison, Madison, WI.,R.M. Bock Laboratories of Cell and Molecular Biology, University of Wisconsin-Madison, Madison, WI
| | - André Leier
- Informatics Institute, School of Medicine, University of Alabama at Birmingham, Birmingham, AL.,Department of Genetics, School of Medicine, University of Alabama at Birmingham, Birmingham, AL
| | - Julio Paez-Valencia
- Department of Botany, University of Wisconsin-Madison, Madison, WI.,R.M. Bock Laboratories of Cell and Molecular Biology, University of Wisconsin-Madison, Madison, WI
| | | | - Kaija Goodman
- Department of Botany, University of Wisconsin-Madison, Madison, WI.,R.M. Bock Laboratories of Cell and Molecular Biology, University of Wisconsin-Madison, Madison, WI
| | - Nathan Miller
- Department of Botany, University of Wisconsin-Madison, Madison, WI
| | - Paul Ahlquist
- Institute for Molecular Virology, University of Wisconsin-Madison, Madison, WI.,Departments of Oncology, University of Wisconsin-Madison, Madison, WI.,Department of Plant Pathology, University of Wisconsin-Madison, Madison, WI.,Howard Hughes Medical Institute, Chevy Chase, MD.,Morgridge Institute for Research, Madison, WI
| | - Tatiana T Marquez-Lago
- Informatics Institute, School of Medicine, University of Alabama at Birmingham, Birmingham, AL.,Department of Genetics, School of Medicine, University of Alabama at Birmingham, Birmingham, AL
| | - Marisa S Otegui
- Department of Botany, University of Wisconsin-Madison, Madison, WI .,R.M. Bock Laboratories of Cell and Molecular Biology, University of Wisconsin-Madison, Madison, WI.,Department of Genetics, University of Wisconsin-Madison, Madison, WI
| |
Collapse
|