{"id":{"repo_id":"wustl","oai_identifier":"oai:openscholarship.wustl.edu:etd-1322"},"canonical_url":"https://search.dev.ndltd.org/etd/wustl/oai:openscholarship.wustl.edu:etd-1322","repository":{"repo_id":"wustl","name":"Washington University in St. Louis","base_url":"https://openscholarship.wustl.edu/do/oai/"},"display":{"title":"Role And Regulation Of ESCRT-III In Multivesiculr Body Biogenesis","abstract":"Endosomal sorting complex required for transports: ESCRT) machinery responsible for multivesicular body: MVB) biogenesis is essential for receptor downregulation, viral budding and cytokinesis. ESCRT-III is a large polymer built from related ESCRT-III proteins that is thought to help generate intralumenal vesicles: ILVs) within the MVB. How ESCRT-III functions is poorly understood. Although ESCRT-III assembles on the endosomal membrane, its components are predominantly soluble in the cytoplasm. I found that the transition between these two states is controlled by autoinhibitory domains within ESCRT-III proteins, which I identified by structure/ function analysis in four human ESCRT-III proteins - Charged multivesicular body protein2A: CHMP2A), CHMP3, CHMP6, and CHMP4A. Biochemical and functional assays confirmed that the C-terminally located autoinhibitory domains control cycling between a \"closed\" state which they are soluble monomers and an \"open\" state in which they assemble into membrane associated complexes. While searching for cellular factor(s) that might regulate transition between these states, I found that LIP5, a proposed cofactor of the ATPase VPS4, binds efficiently to the autoinhibitory domains of a subset of ESCRT-III proteins including CHMP1B, 2A and 3. Because VPS4 disassembles ESCRT-III complexes, this direct interaction between its cofactor LIP5 and ESCRT-III proteins can enhance VPS4 mediated ESCRT-III disassembly. To ask when and how individual ESCRT-III proteins and VPS4 contribute to ILV formation in cultured cells, I establish reagents to detect and manipulate these proteins including antibodies and effective small interference RNAs. I used these tools to show that representative of two classes of cell surface receptors, epidermal growth factor receptor: EGFR), a tyrosine kinase receptor and delta-opioid receptor: DOR), a G-protein coupled receptor use ESCRT-III and VPS4 to undergo downregulation via lysosomal degradation. Taken together the studies in this thesis provide insights into roles and regulation of ESCRT-III in MVB biogenesis.","abstract_html":"Endosomal sorting complex required for transports: ESCRT) machinery responsible for multivesicular body: MVB) biogenesis is essential for receptor downregulation, viral budding and cytokinesis. ESCRT-III is a large polymer built from related ESCRT-III proteins that is thought to help generate intralumenal vesicles: ILVs) within the MVB. How ESCRT-III functions is poorly understood. Although ESCRT-III assembles on the endosomal membrane, its components are predominantly soluble in the cytoplasm. I found that the transition between these two states is controlled by autoinhibitory domains within ESCRT-III proteins, which I identified by structure/ function analysis in four human ESCRT-III proteins - Charged multivesicular body protein2A: CHMP2A), CHMP3, CHMP6, and CHMP4A. Biochemical and functional assays confirmed that the C-terminally located autoinhibitory domains control cycling between a "closed" state which they are soluble monomers and an "open" state in which they assemble into membrane associated complexes. While searching for cellular factor(s) that might regulate transition between these states, I found that LIP5, a proposed cofactor of the ATPase VPS4, binds efficiently to the autoinhibitory domains of a subset of ESCRT-III proteins including CHMP1B, 2A and 3. Because VPS4 disassembles ESCRT-III complexes, this direct interaction between its cofactor LIP5 and ESCRT-III proteins can enhance VPS4 mediated ESCRT-III disassembly. To ask when and how individual ESCRT-III proteins and VPS4 contribute to ILV formation in cultured cells, I establish reagents to detect and manipulate these proteins including antibodies and effective small interference RNAs. I used these tools to show that representative of two classes of cell surface receptors, epidermal growth factor receptor: EGFR), a tyrosine kinase receptor and delta-opioid receptor: DOR), a G-protein coupled receptor use ESCRT-III and VPS4 to undergo downregulation via lysosomal degradation. Taken together the studies in this thesis provide insights into roles and regulation of ESCRT-III in MVB biogenesis.","abstract_has_math":false,"creators":["Shim, Soomin"],"institution":null,"degree_name":"Doctor of Philosophy (PhD)","degree_level":"Dissertation","degree_discipline":"Biology and Biomedical Sciences: Molecular Cell Biology","degree_department":null,"school":null,"contributors":["Phyllis Hanson"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2009,"date_issued":"2009-01-01T08:00:00Z","date_published":"2009-01-01T08:00:00Z","updated_at":"2026-07-24T06:12:48Z","subjects":["Biology","Cell","endosome","ESCRT","membrane trafficking","membrane transport","multivesicular body","MVB"],"languages":["English (en)"],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier.doi","label":"DOI","values":["https://doi.org/10.7936/K7D50K0Q"],"render_values":[{"text":"https://doi.org/10.7936/K7D50K0Q","href":"https://doi.org/10.7936/K7D50K0Q","code":true}]}]},"links":{"outbound_url":"https://openscholarship.wustl.edu/etd/323","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Phyllis Hanson"]},{"key":"dc:creator","label":"Author","values":["Shim, Soomin"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.available","label":"Dc Date Available","values":["2010-01-01T08:00:00Z"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Biology and Biomedical Sciences: Molecular Cell Biology"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Doctor of Philosophy (PhD)"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Biology","Cell","endosome","ESCRT","membrane trafficking","membrane transport","multivesicular body","MVB"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["English (en)"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://openscholarship.wustl.edu/etd/323"]},{"key":"dc:identifier.doi","label":"DOI","values":["https://doi.org/10.7936/K7D50K0Q"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Endosomal sorting complex required for transports: ESCRT) machinery responsible for multivesicular body: MVB) biogenesis is essential for receptor downregulation, viral budding and cytokinesis. ESCRT-III is a large polymer built from related ESCRT-III proteins that is thought to help generate intralumenal vesicles: ILVs) within the MVB. How ESCRT-III functions is poorly understood. Although ESCRT-III assembles on the endosomal membrane, its components are predominantly soluble in the cytoplasm. I found that the transition between these two states is controlled by autoinhibitory domains within ESCRT-III proteins, which I identified by structure/ function analysis in four human ESCRT-III proteins - Charged multivesicular body protein2A: CHMP2A), CHMP3, CHMP6, and CHMP4A. Biochemical and functional assays confirmed that the C-terminally located autoinhibitory domains control cycling between a \"closed\" state which they are soluble monomers and an \"open\" state in which they assemble into membrane associated complexes. While searching for cellular factor(s) that might regulate transition between these states, I found that LIP5, a proposed cofactor of the ATPase VPS4, binds efficiently to the autoinhibitory domains of a subset of ESCRT-III proteins including CHMP1B, 2A and 3. Because VPS4 disassembles ESCRT-III complexes, this direct interaction between its cofactor LIP5 and ESCRT-III proteins can enhance VPS4 mediated ESCRT-III disassembly. To ask when and how individual ESCRT-III proteins and VPS4 contribute to ILV formation in cultured cells, I establish reagents to detect and manipulate these proteins including antibodies and effective small interference RNAs. I used these tools to show that representative of two classes of cell surface receptors, epidermal growth factor receptor: EGFR), a tyrosine kinase receptor and delta-opioid receptor: DOR), a G-protein coupled receptor use ESCRT-III and VPS4 to undergo downregulation via lysosomal degradation. Taken together the studies in this thesis provide insights into roles and regulation of ESCRT-III in MVB biogenesis."]},{"key":"dc:title","label":"Title","values":["Role And Regulation Of ESCRT-III In Multivesiculr Body Biogenesis"]}]}],"canonical_facts":{"dc:contributor":["Phyllis Hanson"],"dc:creator":["Shim, Soomin"],"dc:date.available":["2010-01-01T08:00:00Z"],"dc:description.abstract":["Endosomal sorting complex required for transports: ESCRT) machinery responsible for multivesicular body: MVB) biogenesis is essential for receptor downregulation, viral budding and cytokinesis. ESCRT-III is a large polymer built from related ESCRT-III proteins that is thought to help generate intralumenal vesicles: ILVs) within the MVB. How ESCRT-III functions is poorly understood. Although ESCRT-III assembles on the endosomal membrane, its components are predominantly soluble in the cytoplasm. I found that the transition between these two states is controlled by autoinhibitory domains within ESCRT-III proteins, which I identified by structure/ function analysis in four human ESCRT-III proteins - Charged multivesicular body protein2A: CHMP2A), CHMP3, CHMP6, and CHMP4A. Biochemical and functional assays confirmed that the C-terminally located autoinhibitory domains control cycling between a \"closed\" state which they are soluble monomers and an \"open\" state in which they assemble into membrane associated complexes. While searching for cellular factor(s) that might regulate transition between these states, I found that LIP5, a proposed cofactor of the ATPase VPS4, binds efficiently to the autoinhibitory domains of a subset of ESCRT-III proteins including CHMP1B, 2A and 3. Because VPS4 disassembles ESCRT-III complexes, this direct interaction between its cofactor LIP5 and ESCRT-III proteins can enhance VPS4 mediated ESCRT-III disassembly. To ask when and how individual ESCRT-III proteins and VPS4 contribute to ILV formation in cultured cells, I establish reagents to detect and manipulate these proteins including antibodies and effective small interference RNAs. I used these tools to show that representative of two classes of cell surface receptors, epidermal growth factor receptor: EGFR), a tyrosine kinase receptor and delta-opioid receptor: DOR), a G-protein coupled receptor use ESCRT-III and VPS4 to undergo downregulation via lysosomal degradation. Taken together the studies in this thesis provide insights into roles and regulation of ESCRT-III in MVB biogenesis."],"dc:identifier":["https://openscholarship.wustl.edu/etd/323"],"dc:identifier.doi":["https://doi.org/10.7936/K7D50K0Q"],"dc:language":["English (en)"],"dc:subject":["Biology","Cell","endosome","ESCRT","membrane trafficking","membrane transport","multivesicular body","MVB"],"dc:title":["Role And Regulation Of ESCRT-III In Multivesiculr Body Biogenesis"],"thesis:degree_discipline":["Biology and Biomedical Sciences: Molecular Cell Biology"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Doctor of Philosophy (PhD)"]},"updated_at":"2026-07-24T06:12:48Z"}