{"id":{"repo_id":"utswmed","oai_identifier":"oai:utswmed-ir.tdl.org:2152.5/616"},"canonical_url":"https://search.dev.ndltd.org/etd/utswmed/oai:utswmed-ir.tdl.org:2152.5/616","repository":{"repo_id":"utswmed","name":"University of Texas Southwestern Medical Center","base_url":"https://utswmed-ir.tdl.org/server/oai/request"},"display":{"title":"The Function of Phosphatidylinositol 4-Kinase III-Beta in Trypanosoma Brucei","abstract":"Phosphatidylinositol 4-kinase phosphorylates phosphatidylinositol at the D4 position resulting in phosphatidylinositol 4-monophosphate. Subsequent phosphorylation events result in a group of molecules known as phosphoinositides. These molecules are important in signal transduction, endocytosis, exocytosis, and protein trafficking. Two phosphatidylinositol 4-kinases are found in Trypanosoma Brucei. We have cloned the gene encoding the Type III phosphatidylinositol 4-kinase Beta (TbPI4KIII-ß) in Trypanosoma Brucei. The protein was exogenously expressed in COS-7 cells and assayed for phosphatidylinositol kinase activity. The expressed protein migrated on SDS-PAGE near the predicted molecular weight of 66 kDa and phosphorylates phosphatidylinositol. Depletion of TbPI4KIII-ß in procyclic T. brucei by RNAi results in inhibition of cell growth and a distorted cellular morphology. Immunofluorescence studies revealed a distorted Golgi apparatus and mislocalization of lysosomal and flagellar pocket proteins. Ultrastructural analysis reveals internal accumulation of a heterogeneous population of vesicles, abnormal positioning of organelles and a loss of cell polarity. Scanning EM reveals a twisted morphology most likely due to an alteration in the microtubule cytoskeleton. Dividing TbPI4KIII-ß RNAi trypanosomes often exhibited a detached daughter flagellum and lacked a cleavage furrow, suggesting a defect in cell division and/or cytokinesis. Cell cycle analysis confirmed that cells depleted of TbPI4KIII-ß have a post-mitotic cytokinesis block. In summary, TbPI4KIII-ß is an essential protein in procyclic T. brucei, required for maintenance of Golgi structure, protein trafficking, normal cellular shape and cytokinesis.","abstract_html":"Phosphatidylinositol 4-kinase phosphorylates phosphatidylinositol at the D4 position resulting in phosphatidylinositol 4-monophosphate. Subsequent phosphorylation events result in a group of molecules known as phosphoinositides. These molecules are important in signal transduction, endocytosis, exocytosis, and protein trafficking. Two phosphatidylinositol 4-kinases are found in Trypanosoma Brucei. We have cloned the gene encoding the Type III phosphatidylinositol 4-kinase Beta (TbPI4KIII-ß) in Trypanosoma Brucei. The protein was exogenously expressed in COS-7 cells and assayed for phosphatidylinositol kinase activity. The expressed protein migrated on SDS-PAGE near the predicted molecular weight of 66 kDa and phosphorylates phosphatidylinositol. Depletion of TbPI4KIII-ß in procyclic T. brucei by RNAi results in inhibition of cell growth and a distorted cellular morphology. Immunofluorescence studies revealed a distorted Golgi apparatus and mislocalization of lysosomal and flagellar pocket proteins. Ultrastructural analysis reveals internal accumulation of a heterogeneous population of vesicles, abnormal positioning of organelles and a loss of cell polarity. Scanning EM reveals a twisted morphology most likely due to an alteration in the microtubule cytoskeleton. Dividing TbPI4KIII-ß RNAi trypanosomes often exhibited a detached daughter flagellum and lacked a cleavage furrow, suggesting a defect in cell division and/or cytokinesis. Cell cycle analysis confirmed that cells depleted of TbPI4KIII-ß have a post-mitotic cytokinesis block. In summary, TbPI4KIII-ß is an essential protein in procyclic T. brucei, required for maintenance of Golgi structure, protein trafficking, normal cellular shape and cytokinesis.","abstract_has_math":false,"creators":["Rodgers, Melissa Jeane"],"institution":null,"degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":["Phillips, Margaret A."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2010,"date_issued":"2010-07-12T18:37:04Z","date_published":"2010-07-12T18:37:04Z","updated_at":"2026-07-24T05:52:13Z","subjects":["Trypanosoma brucei brucei","1-Phosphatidylinositol 4-Kinase","Cloning, Molecular"],"languages":["en"],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["244106145"],"render_values":[{"text":"244106145","href":null,"code":true}]}]},"links":{"outbound_url":"https://hdl.handle.net/2152.5/616","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Phillips, Margaret A."]},{"key":"dc:creator","label":"Author","values":["Rodgers, Melissa Jeane"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2010-07-12T18:37:04Z","2006-12-20"]},{"key":"dc:type","label":"Dc Type","values":["Thesis","Text","dissertation"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Trypanosoma brucei brucei","1-Phosphatidylinositol 4-Kinase","Cloning, Molecular"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://hdl.handle.net/2152.5/616","244106145"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Phosphatidylinositol 4-kinase phosphorylates phosphatidylinositol at the D4 position resulting in phosphatidylinositol 4-monophosphate. Subsequent phosphorylation events result in a group of molecules known as phosphoinositides. These molecules are important in signal transduction, endocytosis, exocytosis, and protein trafficking. Two phosphatidylinositol 4-kinases are found in Trypanosoma Brucei. We have cloned the gene encoding the Type III phosphatidylinositol 4-kinase Beta (TbPI4KIII-ß) in Trypanosoma Brucei. The protein was exogenously expressed in COS-7 cells and assayed for phosphatidylinositol kinase activity. The expressed protein migrated on SDS-PAGE near the predicted molecular weight of 66 kDa and phosphorylates phosphatidylinositol. Depletion of TbPI4KIII-ß in procyclic T. brucei by RNAi results in inhibition of cell growth and a distorted cellular morphology. Immunofluorescence studies revealed a distorted Golgi apparatus and mislocalization of lysosomal and flagellar pocket proteins. Ultrastructural analysis reveals internal accumulation of a heterogeneous population of vesicles, abnormal positioning of organelles and a loss of cell polarity. Scanning EM reveals a twisted morphology most likely due to an alteration in the microtubule cytoskeleton. Dividing TbPI4KIII-ß RNAi trypanosomes often exhibited a detached daughter flagellum and lacked a cleavage furrow, suggesting a defect in cell division and/or cytokinesis. Cell cycle analysis confirmed that cells depleted of TbPI4KIII-ß have a post-mitotic cytokinesis block. In summary, TbPI4KIII-ß is an essential protein in procyclic T. brucei, required for maintenance of Golgi structure, protein trafficking, normal cellular shape and cytokinesis."]},{"key":"dc:format","label":"Dc Format","values":["Electronic","application/pdf","born digital"]},{"key":"dc:title","label":"Title","values":["The Function of Phosphatidylinositol 4-Kinase III-Beta in Trypanosoma Brucei"]}]}],"canonical_facts":{"dc:contributor":["Phillips, Margaret A."],"dc:creator":["Rodgers, Melissa Jeane"],"dc:date":["2010-07-12T18:37:04Z","2006-12-20"],"dc:description":["Phosphatidylinositol 4-kinase phosphorylates phosphatidylinositol at the D4 position resulting in phosphatidylinositol 4-monophosphate. Subsequent phosphorylation events result in a group of molecules known as phosphoinositides. These molecules are important in signal transduction, endocytosis, exocytosis, and protein trafficking. Two phosphatidylinositol 4-kinases are found in Trypanosoma Brucei. We have cloned the gene encoding the Type III phosphatidylinositol 4-kinase Beta (TbPI4KIII-ß) in Trypanosoma Brucei. The protein was exogenously expressed in COS-7 cells and assayed for phosphatidylinositol kinase activity. The expressed protein migrated on SDS-PAGE near the predicted molecular weight of 66 kDa and phosphorylates phosphatidylinositol. Depletion of TbPI4KIII-ß in procyclic T. brucei by RNAi results in inhibition of cell growth and a distorted cellular morphology. Immunofluorescence studies revealed a distorted Golgi apparatus and mislocalization of lysosomal and flagellar pocket proteins. Ultrastructural analysis reveals internal accumulation of a heterogeneous population of vesicles, abnormal positioning of organelles and a loss of cell polarity. Scanning EM reveals a twisted morphology most likely due to an alteration in the microtubule cytoskeleton. Dividing TbPI4KIII-ß RNAi trypanosomes often exhibited a detached daughter flagellum and lacked a cleavage furrow, suggesting a defect in cell division and/or cytokinesis. Cell cycle analysis confirmed that cells depleted of TbPI4KIII-ß have a post-mitotic cytokinesis block. In summary, TbPI4KIII-ß is an essential protein in procyclic T. brucei, required for maintenance of Golgi structure, protein trafficking, normal cellular shape and cytokinesis."],"dc:format":["Electronic","application/pdf","born digital"],"dc:identifier":["https://hdl.handle.net/2152.5/616","244106145"],"dc:language":["en"],"dc:subject":["Trypanosoma brucei brucei","1-Phosphatidylinositol 4-Kinase","Cloning, Molecular"],"dc:title":["The Function of Phosphatidylinositol 4-Kinase III-Beta in Trypanosoma Brucei"],"dc:type":["Thesis","Text","dissertation"]},"updated_at":"2026-07-24T05:52:13Z"}