title: Regulation of yeast ESCRT-III membrane scission activity by the Doa4 ubiquitin hydrolase.
abstract: ESCRT-III executes membrane scission during the budding of intralumenal vesicles (ILVs) at endosomes. The scission mechanism is unknown but appears to be linked to the cycle of assembly and disassembly of ESCRT-III complexes at membranes. Regulating this cycle is therefore expected to be important for determining the timing of ESCRT-III-mediated membrane scission. We show that inSaccharomyces cerevisiae, ESCRT-III complexes are stabilized and ILV membrane scission is delayed by Doa4, which is the ubiquitin hydrolase that deubiquitinates transmembrane proteins sorted as cargoes into ILVs. These results suggest a mechanism to delay ILV budding while cargoes undergo deubiquitination. We further show that deubiquitination of ILV cargoes is inhibited via Doa4 binding to Vps20, which is the subunit of ESCRT-III that initiates assembly of the complex. Current models suggest that ESCRT-III complexes surround ubiquitinated cargoes to trap them at the site of ILV budding while the cargoes undergo deubiquitination. Thus our results also propose a mechanism to prevent the onset of ILV cargo deubiquitination at the initiation of ESCRT-III complex assembly.
authors.affiliation: Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, CO 80309.
authors.forename: Natalie
authors.initials: N
authors.lastname: Johnson
authors.affiliation: Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, CO 80309.
authors.forename: Matt
authors.initials: M
authors.lastname: West
authors.affiliation: Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, CO 80309 odorizzi@colorado.edu.
authors.forename: Greg
authors.initials: G
authors.lastname: Odorizzi
mesh_terms: D002455:Cell Division / Q000502:physiology; D010450:Endopeptidases / Q000378:metabolism*; D056827:Endosomal Sorting Complexes Required for Transport / Q000378:metabolism*; D011992:Endosomes / Q000378:metabolism; D007425:Intracellular Membranes / Q000378:metabolism; D057146:Multivesicular Bodies / Q000378:metabolism; D011485:Protein Binding; D021381:Protein Transport; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*; D025801:Ubiquitin / Q000378:metabolism; D043222:Ubiquitin Thiolesterase / Q000378:metabolism*
chemical_list: C084434:DOA4 protein, S cerevisiae; D056827:Endosomal Sorting Complexes Required for Transport; D029701:Saccharomyces cerevisiae Proteins; D025801:Ubiquitin; D010450:Endopeptidases; D043222:Ubiquitin Thiolesterase