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dc.contributor.authorYou, Nancyen
dc.date.accessioned2020-06-29T19:09:00Z
dc.date.available2020-06-29T19:09:00Z
dc.identifier.urihttp://hdl.handle.net/1974/27928
dc.description.abstractThe voltage-gated potassium channel Kv1.5 plays an important role in atrial repolarization and vascular tone of pulmonary arteries. Dysfunction of Kv1.5 channels can lead to atrial fibrillation and pulmonary hypertension, both of which are associated with hypoxia. In the present study, we investigated the effects of hypoxia on Kv1.5 channels. We induced hypoxia by culturing Kv1.5-expressing HEK 293 cells and neonatal rat ventricular myocytes in hypoxic conditions (0.5% O2) and then recorded Kv1.5 current using whole-cell voltage clamp. We observed that 3 hours of hypoxic culture reduced current after 3 hours. Using immunofluorescent staining and western blot analysis, we found that hypoxic culture-induced decrease in current was not caused by the internalization of mature Kv1.5 channels from the membrane. However, we found that hypoxia-induced current reduction is mediated through reactive oxygen species (ROS). First, hydrogen peroxide (H2O2) treatment decreased current in a manner similar to hypoxic culture. Second, the addition of dithiothreitol (DTT), a reducing agent, abolished the effects of hypoxia-induced current reduction. Therefore, our results demonstrate that disrupting ROS-mediated posttranslational modification abolishes the hypoxia-induced reduction in Kv1.5 current. Furthermore, hypoxia-induced reduction in Kv1.5 current required specific cysteine residues within the Kv1.5 channel; using point mutations, our results showed that mutation of Cys581 abolished hypoxia-induced current reduction. Therefore, we have demonstrated that hypoxia decreases IKv1.5 through the production of ROS and that the subsequent posttranslational modifications involve Cys581.en
dc.language.isoengen
dc.relation.ispartofseriesCanadian thesesen
dc.rightsQueen's University's Thesis/Dissertation Non-Exclusive License for Deposit to QSpace and Library and Archives Canadaen
dc.rightsProQuest PhD and Master's Theses International Dissemination Agreementen
dc.rightsIntellectual Property Guidelines at Queen's Universityen
dc.rightsCopying and Preserving Your Thesisen
dc.rightsThis publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner.en
dc.subjectKv1.5en
dc.subjectROSen
dc.subjectReactive oxygen speciesen
dc.subjectAFen
dc.subjectatrial fibrillationen
dc.subjectultra-rapid delayed rectifier potassium currenten
dc.subjectHEKen
dc.titleHypoxia inhibits Kv1.5 currents through reactive oxygen species-mediated post translational cysteine modificationen
dc.typethesisen
dc.description.degreeM.Sc.en
dc.contributor.supervisorZhang, Shetuan
dc.contributor.departmentBiomedical and Molecular Sciencesen
dc.embargo.termsThe lab will be working to publish or use thesis results for a grant and so would like to keep material private for the next few years.en
dc.embargo.liftdate2025-06-26T01:29:59Z
dc.degree.grantorQueen's University at Kingstonen


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