{"id":{"repo_id":"toronto-retro","oai_identifier":"oai:utoronto.scholaris.ca:1807/128228"},"canonical_url":"https://search.dev.ndltd.org/etd/toronto-retro/oai:utoronto.scholaris.ca:1807/128228","repository":{"repo_id":"toronto-retro","name":"University of Toronto","base_url":"https://utoronto.scholaris.ca/server/oai/request"},"display":{"title":"Structure of the Human VPS33B/VPS16B Complex","abstract":"In humans, variants affecting expression/function of VPS33B or VPS16B (VIPAS39) can cause arthrogryposis, renal dysfunction and cholestasis (ARC) syndrome, a rare neonatal lethal condition with symptoms affecting many organ systems. These proteins form a VPS33B/VPS16B complex which is required for many cellular processes, including the production by bone marrow megakaryocytes of protein-carrying alpha granules, which are absent in the platelets of ARC syndrome patients. Previous students in the Kahr Lab studied the VPS33B/VPS16B complex by a variety of means, including negative-staining electron microscopy (EM), which yielded the dimensions and overall shape of a complex with two lobes resembling a dumbbell. However, key aspects of the complex including the molecular weight, composition and subunit arrangement remained elusive. My work demonstrates that human VPS33B/VPS16B is a pentameric complex containing two molecules of VPS33B and 3 of VPS16B. Negative staining EM imaging of avidin-labeled complex showed the VPS33B subunits present in opposing lobes, oriented in trans. Analysis of the effects of VPS16B truncations revealed that a central domain of this subunit is required for stable assembly of the complex. This work significantly advanced knowledge of the structure and composition of VPS33B/VPS16B, providing details that point to key insights into the potential cellular functions of this complex. I also developed a reliable, scalable and easy-to-modify expression system for recombinant human VPS33B/VPS16B, a library of mutated and truncated complexes, and a TEV-protease cleavable version of VPS33B that will support future research into VPS33B/VPS16B function.","abstract_html":"In humans, variants affecting expression/function of VPS33B or VPS16B (VIPAS39) can cause arthrogryposis, renal dysfunction and cholestasis (ARC) syndrome, a rare neonatal lethal condition with symptoms affecting many organ systems. These proteins form a VPS33B/VPS16B complex which is required for many cellular processes, including the production by bone marrow megakaryocytes of protein-carrying alpha granules, which are absent in the platelets of ARC syndrome patients. Previous students in the Kahr Lab studied the VPS33B/VPS16B complex by a variety of means, including negative-staining electron microscopy (EM), which yielded the dimensions and overall shape of a complex with two lobes resembling a dumbbell. However, key aspects of the complex including the molecular weight, composition and subunit arrangement remained elusive. My work demonstrates that human VPS33B/VPS16B is a pentameric complex containing two molecules of VPS33B and 3 of VPS16B. Negative staining EM imaging of avidin-labeled complex showed the VPS33B subunits present in opposing lobes, oriented in trans. Analysis of the effects of VPS16B truncations revealed that a central domain of this subunit is required for stable assembly of the complex. This work significantly advanced knowledge of the structure and composition of VPS33B/VPS16B, providing details that point to key insights into the potential cellular functions of this complex. I also developed a reliable, scalable and easy-to-modify expression system for recombinant human VPS33B/VPS16B, a library of mutated and truncated complexes, and a TEV-protease cleavable version of VPS33B that will support future research into VPS33B/VPS16B function.","abstract_has_math":false,"creators":["Liu, Jia Yuan (Richard)"],"institution":null,"degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":"Biochemistry","school":null,"contributors":[],"advisors":["Kahr, Walter HA"],"committee_chairs":[],"committee_members":[],"year":2023,"date_issued":"2023-06","date_published":"2023-06","updated_at":"2026-07-27T21:28:05Z","subjects":[],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/1807/128228","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Kahr, Walter HA"]},{"key":"dc:contributor.department","label":"Department","values":["Biochemistry"]},{"key":"dc:creator","label":"Author","values":["Liu, Jia Yuan (Richard)"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2023-06"]},{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2023-06-27T16:47:37Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2023-06-27T16:47:37Z"]},{"key":"dc:date.issued","label":"Date","values":["2023-06"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/1807/128228"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["In humans, variants affecting expression/function of VPS33B or VPS16B (VIPAS39) can cause arthrogryposis, renal dysfunction and cholestasis (ARC) syndrome, a rare neonatal lethal condition with symptoms affecting many organ systems. These proteins form a VPS33B/VPS16B complex which is required for many cellular processes, including the production by bone marrow megakaryocytes of protein-carrying alpha granules, which are absent in the platelets of ARC syndrome patients. Previous students in the Kahr Lab studied the VPS33B/VPS16B complex by a variety of means, including negative-staining electron microscopy (EM), which yielded the dimensions and overall shape of a complex with two lobes resembling a dumbbell. However, key aspects of the complex including the molecular weight, composition and subunit arrangement remained elusive. My work demonstrates that human VPS33B/VPS16B is a pentameric complex containing two molecules of VPS33B and 3 of VPS16B. Negative staining EM imaging of avidin-labeled complex showed the VPS33B subunits present in opposing lobes, oriented in trans. Analysis of the effects of VPS16B truncations revealed that a central domain of this subunit is required for stable assembly of the complex. This work significantly advanced knowledge of the structure and composition of VPS33B/VPS16B, providing details that point to key insights into the potential cellular functions of this complex. I also developed a reliable, scalable and easy-to-modify expression system for recombinant human VPS33B/VPS16B, a library of mutated and truncated complexes, and a TEV-protease cleavable version of VPS33B that will support future research into VPS33B/VPS16B function."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Ph.D."]},{"key":"dc:title","label":"Title","values":["Structure of the Human VPS33B/VPS16B Complex"]}]}],"canonical_facts":{"dc:contributor.advisor":["Kahr, Walter HA"],"dc:contributor.department":["Biochemistry"],"dc:creator":["Liu, Jia Yuan (Richard)"],"dc:date":["2023-06"],"dc:date.accessioned":["2023-06-27T16:47:37Z"],"dc:date.available":["2023-06-27T16:47:37Z"],"dc:date.issued":["2023-06"],"dc:description.abstract":["In humans, variants affecting expression/function of VPS33B or VPS16B (VIPAS39) can cause arthrogryposis, renal dysfunction and cholestasis (ARC) syndrome, a rare neonatal lethal condition with symptoms affecting many organ systems. These proteins form a VPS33B/VPS16B complex which is required for many cellular processes, including the production by bone marrow megakaryocytes of protein-carrying alpha granules, which are absent in the platelets of ARC syndrome patients. Previous students in the Kahr Lab studied the VPS33B/VPS16B complex by a variety of means, including negative-staining electron microscopy (EM), which yielded the dimensions and overall shape of a complex with two lobes resembling a dumbbell. However, key aspects of the complex including the molecular weight, composition and subunit arrangement remained elusive. My work demonstrates that human VPS33B/VPS16B is a pentameric complex containing two molecules of VPS33B and 3 of VPS16B. Negative staining EM imaging of avidin-labeled complex showed the VPS33B subunits present in opposing lobes, oriented in trans. Analysis of the effects of VPS16B truncations revealed that a central domain of this subunit is required for stable assembly of the complex. This work significantly advanced knowledge of the structure and composition of VPS33B/VPS16B, providing details that point to key insights into the potential cellular functions of this complex. I also developed a reliable, scalable and easy-to-modify expression system for recombinant human VPS33B/VPS16B, a library of mutated and truncated complexes, and a TEV-protease cleavable version of VPS33B that will support future research into VPS33B/VPS16B function."],"dc:description.degree":["Ph.D."],"dc:identifier.uri":["http://hdl.handle.net/1807/128228"],"dc:title":["Structure of the Human VPS33B/VPS16B Complex"],"dc:type":["Thesis"]},"updated_at":"2026-07-27T21:28:05Z"}