The ESCRT pathway.

Multivesicular bodies (MVBs) deliver cargo destined for degradation to the vacuole or lysosome. The ESCRT (endosomal sorting complex required for transport) pathway is a key mediator of MVB biogenesis, but it also plays critical roles in retroviral budding and cytokinetic abscission. Despite these diverse roles, the ESCRT pathway can be simply seen as a cargo-recognition and membrane-sculpting machine viewable from three distinct perspectives: (1) the ESCRT proteins themselves, (2) the cargo they sort, and (3) the membrane they deform. Here, we review ESCRT function from these perspectives and discuss how ESCRTs may drive vesicle budding.

[1]  Simon C Watkins,et al.  Sar1 assembly regulates membrane constriction and ER export , 2010, The Journal of cell biology.

[2]  S. Gygi,et al.  Identification of human MVB12 proteins as ESCRT-I subunits that function in HIV budding. , 2007, Cell host & microbe.

[3]  W. C. Funk,et al.  Requirement for microtubules in new membrane formation during cytokinesis of Xenopus embryos. , 1998, Developmental biology.

[4]  J. Hurley,et al.  Molecular Mechanism of Multivesicular Body Biogenesis by ESCRT Complexes , 2010, Nature.

[5]  Rebecca L Rich,et al.  Structure and functional interactions of the Tsg101 UEV domain , 2002, The EMBO journal.

[6]  B. González,et al.  ESCRT-II, an endosome-associated complex required for protein sorting: crystal structure and interactions with ESCRT-III and membranes. , 2004, Developmental cell.

[7]  W. Sundquist,et al.  Structure and ESCRT-III protein interactions of the MIT domain of human VPS4A. , 2005, Proceedings of the National Academy of Sciences of the United States of America.

[8]  P. Woodman,et al.  TSG101/Mammalian VPS23 and Mammalian VPS28 Interact Directly and Are Recruited to VPS4-induced Endosomes* , 2001, The Journal of Biological Chemistry.

[9]  H. McMahon,et al.  Mechanisms of endocytosis. , 2009, Annual review of biochemistry.

[10]  S. Emr,et al.  ESCRTs and human disease. , 2009, Biochemical Society transactions.

[11]  N. Tanaka,et al.  AMSH, an ESCRT-III associated enzyme, deubiquitinates cargo on MVB/late endosomes. , 2007, Cell structure and function.

[12]  Markus Babst,et al.  Efficient cargo sorting by ESCRT-I and the subsequent release of ESCRT-I from multivesicular bodies requires the subunit Mvb12. , 2006, Molecular biology of the cell.

[13]  S. Emr,et al.  Ubiquitin-Dependent Sorting into the Multivesicular Body Pathway Requires the Function of a Conserved Endosomal Protein Sorting Complex, ESCRT-I , 2001, Cell.

[14]  P. Hanson,et al.  Structure/Function Analysis of Four Core ESCRT‐III Proteins Reveals Common Regulatory Role for Extreme C‐Terminal Domain , 2007, Traffic.

[15]  Roger L. Williams,et al.  The emerging shape of the ESCRT machinery , 2007, Nature Reviews Molecular Cell Biology.

[16]  Martin Lenz,et al.  Membrane buckling induced by curved filaments. , 2009, Physical review letters.

[17]  W. Sundquist,et al.  Human ESCRT-III and VPS4 proteins are required for centrosome and spindle maintenance , 2010, Proceedings of the National Academy of Sciences.

[18]  Jacob Piehler,et al.  Helical Structures of ESCRT-III Are Disassembled by VPS4 , 2008, Science.

[19]  H. Stenmark,et al.  STAM and Hrs Are Subunits of a Multivalent Ubiquitin-binding Complex on Early Endosomes* , 2003, The Journal of Biological Chemistry.

[20]  P. Nash,et al.  AMSH Interacts with ESCRT-0 to Regulate the Stability and Trafficking of CXCR4* , 2010, The Journal of Biological Chemistry.

[21]  T. Baker,et al.  ClpX-mediated remodeling of mu transpososomes: selective unfolding of subunits destabilizes the entire complex. , 2001, Molecular cell.

[22]  J. Reinstein,et al.  Disaggregases in 4 dimensions. , 2010, Current opinion in structural biology.

[23]  Rolf Bernander,et al.  A unique cell division machinery in the Archaea , 2008, Proceedings of the National Academy of Sciences.

[24]  S. Emr,et al.  Endosomal transport function in yeast requires a novel AAA‐type ATPase, Vps4p , 1997, The EMBO journal.

[25]  R. D. Fisher,et al.  Structure and Ubiquitin Binding of the Ubiquitin-interacting Motif* , 2003, Journal of Biological Chemistry.

[26]  T. O'Halloran,et al.  Cytokinesis failure in clathrin-minus cells is caused by cleavage furrow instability. , 2001, Cell motility and the cytoskeleton.

[27]  D. I. Svergun,et al.  A crescent-shaped ALIX dimer targets ESCRT-III CHMP4 filaments. , 2009, Structure.

[28]  S. Emr,et al.  Ordered assembly of the ESCRT-III complex on endosomes is required to sequester cargo during MVB formation. , 2008, Developmental cell.

[29]  N. Tanaka,et al.  Hrs Is Associated with STAM, a Signal-transducing Adaptor Molecule , 1997, The Journal of Biological Chemistry.

[30]  J. Dukes,et al.  A dominant-negative ESCRT-III protein perturbs cytokinesis and trafficking to lysosomes. , 2008, The Biochemical journal.

[31]  J. Hurley,et al.  Integrated structural model and membrane targeting mechanism of the human ESCRT-II complex. , 2008, Developmental cell.

[32]  R. Lamb,et al.  Mechanisms for enveloped virus budding: can some viruses do without an ESCRT? , 2008, Virology.

[33]  P. Roy,et al.  Nonstructural Protein 3 of Bluetongue Virus Assists Virus Release by Recruiting ESCRT-I Protein Tsg101 , 2006, Journal of Virology.

[34]  A. Horwich,et al.  Global unfolding of a substrate protein by the Hsp100 chaperone ClpA , 1999, Nature.

[35]  A. Amerik,et al.  The Doa4 deubiquitinating enzyme is required for ubiquitin homeostasis in yeast. , 1999, Molecular biology of the cell.

[36]  R. Schekman,et al.  Vesicle budding from endoplasmic reticulum. , 2002, Methods in enzymology.

[37]  A. F. Neuwald,et al.  Assembly , Operation , and Disassembly of Protein Complexes : A Class of Chaperone-Like ATPases Associated with the + AAA , 1999 .

[38]  Petra Schwille,et al.  Ceramide Triggers Budding of Exosome Vesicles into Multivesicular Endosomes , 2008, Science.

[39]  T. Stevens,et al.  Characterization of genes required for protein sorting and vacuolar function in the yeast Saccharomyces cerevisiae. , 1989, The EMBO journal.

[40]  S. Emr,et al.  Novel Ist1-Did2 complex functions at a late step in multivesicular body sorting. , 2007, Molecular biology of the cell.

[41]  M. Stowell,et al.  Nucleotide-dependent conformational changes in dynamin: evidence for a mechanochemical molecular spring , 1999, Nature Cell Biology.

[42]  F. Striebel,et al.  Controlled destruction: AAA+ ATPases in protein degradation from bacteria to eukaryotes. , 2009, Current opinion in structural biology.

[43]  H. McMahon,et al.  Bar Domains and Membrane Curvature: Bringing Your Curves to the Bar , 2022 .

[44]  H. Stenmark,et al.  Double-sided ubiquitin binding of Hrs-UIM in endosomal protein sorting , 2006, Nature Structural &Molecular Biology.

[45]  Stefan Matile,et al.  Role of LBPA and Alix in Multivesicular Liposome Formation and Endosome Organization , 2004, Science.

[46]  J. Martin-Serrano,et al.  Parallels Between Cytokinesis and Retroviral Budding: A Role for the ESCRT Machinery , 2007, Science.

[47]  Scott D Emr,et al.  Ubiquitin interactions of NZF zinc fingers , 2004, The EMBO journal.

[48]  David G. Drubin,et al.  A Modular Design for the Clathrin- and Actin-Mediated Endocytosis Machinery , 2005, Cell.

[49]  Markus Babst,et al.  Escrt-III: an endosome-associated heterooligomeric protein complex required for mvb sorting. , 2002, Developmental cell.

[50]  Fulvio Reggiori,et al.  Sorting of proteins into multivesicular bodies: ubiquitin‐dependent and ‐independent targeting , 2001, The EMBO journal.

[51]  P. Bieniasz,et al.  Dynamics of ESCRT protein recruitment during retroviral assembly , 2011, Nature Cell Biology.

[52]  W. Weissenhorn,et al.  Structural basis for budding by the ESCRT-III factor CHMP3. , 2006, Developmental cell.

[53]  I. Madshus,et al.  Hrs sorts ubiquitinated proteins into clathrin-coated microdomains of early endosomes , 2002, Nature Cell Biology.

[54]  Harald Stenmark,et al.  The ESCRT machinery in endosomal sorting of ubiquitylated membrane proteins , 2009, Nature.

[55]  W. Sundquist,et al.  Structural Basis for ESCRT-III Protein Autoinhibition , 2009, Nature Structural &Molecular Biology.

[56]  D. Eckert,et al.  Recycling of ESCRTs by the AAA-ATPase Vps4 is regulated by a conserved VSL region in Vta1 , 2006, The Journal of cell biology.

[57]  S. Emr,et al.  Structure and disassembly of filaments formed by the ESCRT-III subunit Vps24. , 2008, Structure.

[58]  G. Barsh,et al.  Spongiform neurodegeneration-associated E3 ligase Mahogunin ubiquitylates TSG101 and regulates endosomal trafficking. , 2007, Molecular biology of the cell.

[59]  P. Camilli,et al.  GTP-dependent twisting of dynamin implicates constriction and tension in membrane fission , 2006, Nature.

[60]  S. Young,et al.  ESCRT-III Dysfunction Causes Autophagosome Accumulation and Neurodegeneration , 2007, Current Biology.

[61]  B. Różycki,et al.  Membrane Budding , 2010, Cell.

[62]  J. Martin-Serrano,et al.  Differential requirements for Alix and ESCRT-III in cytokinesis and HIV-1 release , 2008, Proceedings of the National Academy of Sciences.

[63]  G. Hummer,et al.  The Vps27/Hse1 complex is a GAT domain-based scaffold for ubiquitin-dependent sorting. , 2007, Developmental cell.

[64]  L. Verplank,et al.  Tsg101, a homologue of ubiquitin-conjugating (E2) enzymes, binds the L domain in HIV type 1 Pr55Gag , 2001, Proceedings of the National Academy of Sciences of the United States of America.

[65]  S. Emr,et al.  The Vps4p AAA ATPase regulates membrane association of a Vps protein complex required for normal endosome function , 1998, The EMBO journal.

[66]  R. Piper,et al.  ESCRT ubiquitin-binding domains function cooperatively during MVB cargo sorting , 2009, The Journal of cell biology.

[67]  Zhaohui Xu,et al.  ESCRT-III family members stimulate Vps4 ATPase activity directly or via Vta1. , 2008, Developmental cell.

[68]  K. Rosendal,et al.  The growth-regulatory protein HCRP1/hVps37A is a subunit of mammalian ESCRT-I and mediates receptor down-regulation. , 2004, Molecular biology of the cell.

[69]  Rohit Mittal,et al.  Structure and analysis of FCHo2 F-BAR domain: a dimerizing and membrane recruitment module that effects membrane curvature. , 2007, Structure.

[70]  S. Emr,et al.  Vps27 recruits ESCRT machinery to endosomes during MVB sorting , 2003, The Journal of cell biology.

[71]  R. Beynon,et al.  Activation of the Endosome-Associated Ubiquitin Isopeptidase AMSH by STAM, a Component of the Multivesicular Body-Sorting Machinery , 2006, Current Biology.

[72]  J. Hurley,et al.  Molecular Architecture and Functional Model of the Complete Yeast ESCRT-I Heterotetramer , 2007, Cell.

[73]  S. Emr,et al.  Multivesicular body sorting: ubiquitin ligase Rsp5 is required for the modification and sorting of carboxypeptidase S. , 2003, Molecular biology of the cell.

[74]  S. Emr,et al.  ESCRT-I Core and ESCRT-II GLUE Domain Structures Reveal Role for GLUE in Linking to ESCRT-I and Membranes , 2006, Cell.

[75]  R. Piper,et al.  A single ubiquitin is sufficient for cargo protein entry into MVBs in the absence of ESCRT ubiquitination , 2011, The Journal of cell biology.

[76]  G. Jensen,et al.  Cryo-EM structure of dodecameric Vps4p and its 2:1 complex with Vta1p. , 2008, Journal of molecular biology.

[77]  G. Palù,et al.  A role for ubiquitin ligase recruitment in retrovirus release. , 2000, Proceedings of the National Academy of Sciences of the United States of America.

[78]  A. Horwich,et al.  ClpA mediates directional translocation of substrate proteins into the ClpP protease , 2001, Proceedings of the National Academy of Sciences of the United States of America.

[79]  Stanley N Cohen,et al.  TSG101 interaction with HRS mediates endosomal trafficking and receptor down-regulation , 2003, Proceedings of the National Academy of Sciences of the United States of America.

[80]  K. Porter,et al.  An Electron Microscope Study of the Rat Ovum , 1959, The Journal of biophysical and biochemical cytology.

[81]  Matthew West,et al.  Bro1 binding to Snf7 regulates ESCRT-III membrane scission activity in yeast , 2011, The Journal of cell biology.

[82]  S. Emr,et al.  Fab1p PtdIns(3)P 5-Kinase Function Essential for Protein Sorting in the Multivesicular Body , 1998, Cell.

[83]  S. Schmid,et al.  GTPase Cycle of Dynamin Is Coupled to Membrane Squeeze and Release, Leading to Spontaneous Fission , 2008, Cell.

[84]  Roger L. Williams,et al.  Molecular and structural basis of ESCRT-III recruitment to membranes during archaeal cell division. , 2011, Molecular cell.

[85]  F. Wendler,et al.  ESCRTs and Fab1 Regulate Distinct Steps of Autophagy , 2007, Current Biology.

[86]  R. D. Fisher,et al.  HIV Gag mimics the Tsg101-recruiting activity of the human Hrs protein , 2003, The Journal of cell biology.

[87]  J. Hurley,et al.  Structural and Functional Organization of the ESCRT-I Trafficking Complex , 2006, Cell.

[88]  B. Peter,et al.  BAR Domains as Sensors of Membrane Curvature: The Amphiphysin BAR Structure , 2004, Science.

[89]  W. Sundquist,et al.  Structural and mechanistic studies of VPS4 proteins , 2005, The EMBO journal.

[90]  W. B. Snyder,et al.  Endosome-associated complex, ESCRT-II, recruits transport machinery for protein sorting at the multivesicular body. , 2002, Developmental cell.

[91]  S. Ameer-Beg,et al.  Essential role of hIST1 in cytokinesis. , 2009, Molecular biology of the cell.

[92]  Natalie Elia,et al.  Dynamics of endosomal sorting complex required for transport (ESCRT) machinery during cytokinesis and its role in abscission , 2011, Proceedings of the National Academy of Sciences.

[93]  M. Maki,et al.  Distinct functions of human MVB12A and MVB12B in the ESCRT-I dependent on their posttranslational modifications. , 2010, Biochemical and biophysical research communications.

[94]  M. Hülskamp,et al.  The Arabidopsis elch mutant reveals functions of an ESCRT component in cytokinesis , 2006, Development.

[95]  A. Isaacs,et al.  Functional multivesicular bodies are required for autophagic clearance of protein aggregates associated with neurodegenerative disease , 2007, The Journal of cell biology.

[96]  S. Emr,et al.  Bro1 is an endosome-associated protein that functions in the MVB pathway in Saccharomyces cerevisiae , 2003, Journal of Cell Science.

[97]  Thomas Müller-Reichert,et al.  Cortical Constriction During Abscission Involves Helices of ESCRT-III–Dependent Filaments , 2011, Science.

[98]  S. Emr,et al.  New component of ESCRT-I regulates endosomal sorting complex assembly , 2006, The Journal of cell biology.

[99]  J. Hurley,et al.  VHS domains of ESCRT‐0 cooperate in high‐avidity binding to polyubiquitinated cargo , 2010, The EMBO journal.

[100]  W. Sundquist,et al.  The Human Endosomal Sorting Complex Required for Transport (ESCRT-I) and Its Role in HIV-1 Budding*♦ , 2004, Journal of Biological Chemistry.

[101]  Joshua D. Schnell,et al.  Epsins and Vps27p/Hrs contain ubiquitin-binding domains that function in receptor endocytosis , 2002, Nature Cell Biology.

[102]  M. Babst.  A Protein's Final ESCRT , 2005, Traffic.

[103]  Mark C. Field,et al.  Evolution of the Multivesicular Body ESCRT Machinery; Retention Across the Eukaryotic Lineage , 2008, Traffic.

[104]  J. Rothman,et al.  Protein Sorting by Transport Vesicles , 1996, Science.

[105]  G. Hummer,et al.  Hybrid Structural Model of the Complete Human ESCRT‐0 Complex , 2009, Structure.

[106]  S. Radoshitzky,et al.  Release of autoinhibition converts ESCRT-III components into potent inhibitors of HIV-1 budding , 2006, Proceedings of the National Academy of Sciences.

[107]  Lindsay N. Carpp,et al.  Interaction between the yellow fever virus nonstructural protein NS3 and the host protein Alix contributes to the release of infectious particles. , 2011, Microbes and infection.

[108]  M. Komada,et al.  STAM proteins bind ubiquitinated proteins on the early endosome via the VHS domain and ubiquitin-interacting motif. , 2003, Molecular biology of the cell.

[109]  Annie Heroux,et al.  Biochemical and structural studies of yeast Vps4 oligomerization. , 2008, Journal of molecular biology.

[110]  Florante A. Quiocho,et al.  Crystal Structure of the VHS and FYVE Tandem Domains of Hrs, a Protein Involved in Membrane Trafficking and Signal Transduction , 2000, Cell.

[111]  G. Palade.  Studies on the endoplasmic reticulum. II. Simple dispositions in cells in situ. , 1955 .

[112]  J. Lippincott-Schwartz,et al.  Structural basis for midbody targeting of spastin by the ESCRT-III protein CHMP1B , 2008, Nature Structural &Molecular Biology.

[113]  A. Amerik,et al.  The Doa4 deubiquitinating enzyme is functionally linked to the vacuolar protein-sorting and endocytic pathways. , 2000, Molecular biology of the cell.

[114]  Jennifer Lippincott-Schwartz,et al.  Membrane scission by the ESCRT-III complex , 2009, Nature.

[115]  S. Emr,et al.  ESCRT‐II coordinates the assembly of ESCRT‐III filaments for cargo sorting and multivesicular body vesicle formation , 2010, The EMBO journal.

[116]  P. Bieniasz,et al.  Identification of Human VPS37C, a Component of Endosomal Sorting Complex Required for Transport-I Important for Viral Budding* , 2005, Journal of Biological Chemistry.

[117]  J. Kaplan,et al.  Characterization of Vta1p, a Class E Vps Protein in Saccharomyces cerevisiae* , 2004, Journal of Biological Chemistry.

[118]  H. Stenmark,et al.  Eap45 in Mammalian ESCRT-II Binds Ubiquitin via a Phosphoinositide-interacting GLUE Domain*♦ , 2005, Journal of Biological Chemistry.

[119]  P. Bieniasz,et al.  HIV-1 and Ebola virus encode small peptide motifs that recruit Tsg101 to sites of particle assembly to facilitate egress , 2001, Nature Medicine.

[120]  J. Klumperman,et al.  Bilayered clathrin coats on endosomal vacuoles are involved in protein sorting toward lysosomes. , 2002, Molecular biology of the cell.

[121]  M. Curtiss,et al.  Assembly of the AAA ATPase Vps4 on ESCRT-III , 2010, Molecular biology of the cell.

[122]  W. Sundquist,et al.  Biochemical analyses of human IST1 and its function in cytokinesis. , 2009, Molecular biology of the cell.

[123]  Natalie Luhtala,et al.  Bro1 coordinates deubiquitination in the multivesicular body pathway by recruiting Doa4 to endosomes , 2004, The Journal of cell biology.

[124]  Randy Schekman,et al.  Sar1p N-Terminal Helix Initiates Membrane Curvature and Completes the Fission of a COPII Vesicle , 2005, Cell.

[125]  I. Amit,et al.  Tal, a Tsg101-specific E3 ubiquitin ligase, regulates receptor endocytosis and retrovirus budding. , 2004, Genes & development.

[126]  S. Redick,et al.  Centriolin Anchoring of Exocyst and SNARE Complexes at the Midbody Is Required for Secretory-Vesicle-Mediated Abscission , 2005, Cell.

[127]  Scott D. Emr,et al.  Structure of the ESCRT-II endosomal trafficking complex , 2004, Nature.

[128]  R. Piper,et al.  The Vps27p–Hse1p complex binds ubiquitin and mediates endosomal protein sorting , 2002, Nature Cell Biology.

[129]  S. Cohen,et al.  Direct visualization of the binding and internalization of a ferritin conjugate of epidermal growth factor in human carcinoma cells A-431 , 1979, The Journal of cell biology.

[130]  Wesley I. Sundquist,et al.  Tsg101 and the Vacuolar Protein Sorting Pathway Are Essential for HIV-1 Budding , 2001, Cell.

[131]  H. Stenmark,et al.  Flat clathrin coats on endosomes mediate degradative protein sorting by scaffolding Hrs in dynamic microdomains , 2006, Journal of Cell Science.

[132]  T. Stevens,et al.  An MBoC Favorite: Morphological classification of the yeast vacuolar protein-sorting mutants: evidence for a prevacuolar compartment in class E vps mutants , 1992, Molecular biology of the cell.

[133]  James D. Riches,et al.  Computational Model of Membrane Fission Catalyzed by ESCRT-III , 2009, PLoS Comput. Biol..

[134]  I. Prior,et al.  The Ubiquitin Isopeptidase UBPY Regulates Endosomal Ubiquitin Dynamics and Is Essential for Receptor Down-regulation* , 2006, Journal of Biological Chemistry.

[135]  S. Schmid,et al.  Dynamin self-assembles into rings suggesting a mechanism for coated vesicle budding , 1995, Nature.

[136]  S. Emr,et al.  Functional Reconstitution of ESCRT-III Assembly and Disassembly , 2009, Cell.

[137]  B. Peter,et al.  Arf family GTP loading is activated by, and generates, positive membrane curvature , 2008, The Biochemical journal.

[138]  P. Hanson,et al.  Plasma membrane deformation by circular arrays of ESCRT-III protein filaments , 2008, The Journal of cell biology.

[139]  Pier Paolo Di Fiore,et al.  A single motif responsible for ubiquitin recognition and monoubiquitination in endocytic proteins , 2002, Nature.

[140]  Jeremy G. Carlton.  The ESCRT machinery: a cellular apparatus for sorting and scission. , 2010, Biochemical Society transactions.

[141]  H. Stenmark,et al.  FYVE and coiled-coil domains determine the specific localisation of Hrs to early endosomes. , 2001, Journal of cell science.

[142]  S. Schmid,et al.  Membrane insertion of the pleckstrin homology domain variable loop 1 is critical for dynamin-catalyzed vesicle scission. , 2009, Molecular biology of the cell.

[143]  Marc C. Johnson,et al.  The C-Terminal Portion of the Hrs Protein Interacts with Tsg101 and Interferes with Human Immunodeficiency Virus Type 1 Gag Particle Production , 2006, Journal of Virology.

[144]  R. D. Fisher,et al.  Human ESCRT-II Complex and Its Role in Human Immunodeficiency Virus Type 1 Release , 2006, Journal of Virology.

[145]  Natalie Luhtala,et al.  Bro 1 coordinates deubiquitination in the multivesicular body pathway by recruiting Doa 4 to endosomes , 2004 .

[146]  S. Emr,et al.  Organelle assembly in yeast: characterization of yeast mutants defective in vacuolar biogenesis and protein sorting , 1988, The Journal of cell biology.

[147]  T. Stevens,et al.  Protein sorting in yeast: Mutants defective in vacuole biogenesis mislocalize vacuolar proteins into the late secretory pathway , 1986, Cell.

[148]  S. Emr,et al.  Structural insight into the ESCRT‐I/‐II link and its role in MVB trafficking , 2007, The EMBO journal.

[149]  Sebastian A. Wagner,et al.  Regulation of ubiquitin-binding proteins by monoubiquitination , 2006, Nature Cell Biology.