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dc.contributor.advisorFisher, Thomas E.en_US
dc.creatorXu, Xiaoyuen_US
dc.date.accessioned2006-04-17T12:00:23Zen_US
dc.date.accessioned2013-01-04T04:29:26Z
dc.date.available2006-04-20T08:00:00Zen_US
dc.date.available2013-01-04T04:29:26Z
dc.date.created2006-04en_US
dc.date.issued2006-04-11en_US
dc.date.submittedApril 2006en_US
dc.identifier.urihttp://hdl.handle.net/10388/etd-04172006-120023en_US
dc.description.abstractTh The kinetics of exocytotic secretion depend not only on the spatial relationship between calcium channels and the exocytotic apparatus, but also on the total amount of Ca2+ influx through Ca2+ channels, the free Ca2+ around the release site and the filling state of the release-ready vesicles. These factors may differ between neurons and endocrine cells. Bovine chromaffin cells (BCCs) are neuroendocrine cells responsible for catecholamine release from the adrenal glands. Ca2+ imaging experiments have shown that localized zones of Ca2+ influx exist on BCC membranes, but how different Ca2+ channel subtypes are distributed, and the mechanisms by which they are targeted, remain to be elucidated. CASK (calcium, calmodulin associated serine kinase) and Mint1 (Munc-18-interacting protein 1), which are modular adaptor proteins involved in synaptic targeting, have recently been found to function in targeting of á1B Ca2+ channels in hippocampal neurons. These data led to the proposal that Ca2+ channels are clustered in BCCs and that CASK and Mint1 play important roles in targeting and/or anchoring channels to their proper location. p*Using RT-PCR and Western blotting, CASK is demonstrated present in isolated BCCs. Mint1 is shown to be present by Western blotting as well. Immunocytochemical experiments and experiments in which BCCs were transfected with plasmids expressing á1A, á1B, and á1C subunits labeled with green fluorescent protein, have shown that á1A and á1B subunits are clustered on the plasma membranes of BCCs, while the á1C subunit is distributed in diffuse patches. With immunoprecipitation, it was determined that CASK interacts biochemically with á1A and á1B Ca2+ channels. Transfection of BCCs with NC3-GFP, which codes for the sequence of the á1B Ca2+ channel that interacts with CASK and Mint1, results in a punctate pattern of fluorescence, which is consistent with the binding of GFP labeled peptide to complexes of CASK and Mint1 at sites of release. Furthermore, immunocytochemical analysis of cells transfected with NC3-GFP showed that á1B Ca2+ channels have a dispersed distribution suggesting that they have been displaced from the binding sites. These data suggest that CASK and Mint1 are important in clustering and targeting Ca2+ channels in the BCC plasma membrane. This study is the first to show the existence and function of CASK and Mint1 in BCCs, and may contribute to our understanding of the exocytotic process in neuroendocrine cellsen_US
dc.language.isoen_USen_US
dc.subjectMint1en_US
dc.subjectCASKen_US
dc.subjectneronendocrine cellsen_US
dc.subjectsecretionen_US
dc.subjectCa2+ channelsen_US
dc.titleThe roles of CASK and mint1 in ca2+ channels clustering and function in bovine chromaffin cellsen_US
thesis.degree.departmentPhysiologyen_US
thesis.degree.disciplinePhysiologyen_US
thesis.degree.grantorUniversity of Saskatchewanen_US
thesis.degree.levelMastersen_US
thesis.degree.nameMaster of Science (M.Sc.)en_US
dc.type.materialtexten_US
dc.type.genreThesisen_US
dc.contributor.committeeMemberRichardson, J. Stevenen_US
dc.contributor.committeeMemberSulakhe, Prakashen_US
dc.contributor.committeeMemberDesautels, Michelen_US
dc.contributor.committeeMemberWalz, Wolfgangen_US


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