{"id":{"repo_id":"uwo","oai_identifier":"oai:uwo.scholaris.ca:20.500.14721/33820"},"canonical_url":"https://search.dev.ndltd.org/etd/uwo/oai:uwo.scholaris.ca:20.500.14721/33820","repository":{"repo_id":"uwo","name":"Western University","base_url":"https://uwo.scholaris.ca/server/oai/request"},"display":{"title":"Putative Pore-lining Residues and Intracellular Magnesium Influence Connexin50 Unitary Gap Junction Channel Conductance","abstract":"Gap junction channels (GJs) are oligomers of connexins forming channels linking neighbouring cells. GJs formed by different connexins show distinct unitary channel conductance (γj), transjunctional-voltage dependent gating (Vj-gating) properties, and magnesium modulation. We investigate here how pore-lining residues may influence these GJ properties. We mutated putative pore-lining residues in Cx50 GJ (G8E/G46E/V53E individually or in combination) to investigate γj, Vj-gating, and magnesium modulation. GJs formed by combination mutants (G8E-G46E, G46E-V53E, and G8E-G46E-V53E) were functional and showed a significantly increased γj with little change in Vj-gating, while G8E-V53E mutants failed to form functional GJs. The γjs of the mutant GJs were reduced up to 30% by inclusion of magnesium in intracellular solution. Studying the individual mutations revealed that magnesium-dependent reduction of γj are due to one or combinations of V53E and/or G46E. Increasing negatively charged glutamate residues at 53rd and/or 46th positions of Cx50 increased magnesium-sensitive ion permeation.","abstract_html":"Gap junction channels (GJs) are oligomers of connexins forming channels linking neighbouring cells. GJs formed by different connexins show distinct unitary channel conductance (γj), transjunctional-voltage dependent gating (Vj-gating) properties, and magnesium modulation. We investigate here how pore-lining residues may influence these GJ properties. We mutated putative pore-lining residues in Cx50 GJ (G8E/G46E/V53E individually or in combination) to investigate γj, Vj-gating, and magnesium modulation. GJs formed by combination mutants (G8E-G46E, G46E-V53E, and G8E-G46E-V53E) were functional and showed a significantly increased γj with little change in Vj-gating, while G8E-V53E mutants failed to form functional GJs. The γjs of the mutant GJs were reduced up to 30% by inclusion of magnesium in intracellular solution. Studying the individual mutations revealed that magnesium-dependent reduction of γj are due to one or combinations of V53E and/or G46E. Increasing negatively charged glutamate residues at 53rd and/or 46th positions of Cx50 increased magnesium-sensitive ion permeation.","abstract_has_math":false,"creators":["Sudhakar, Swathy"],"institution":"The University of Western Ontario","degree_name":"M Sc","degree_level":null,"degree_discipline":"Physiology and Pharmacology","degree_department":null,"school":null,"contributors":[],"advisors":["Bai, Donglin"],"committee_chairs":[],"committee_members":[],"year":2016,"date_issued":"2016-06-23","date_published":"2016-06-23","updated_at":"2026-07-27T21:55:56Z","subjects":["Gap junction channel","unitary conductance","Mg2+-dependent modulation","patch clamp","electrostatics"],"languages":["en_ca"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://hdl.handle.net/20.500.14721/33820","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Bai, Donglin"]},{"key":"dc:creator","label":"Author","values":["Sudhakar, Swathy"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2025-07-10T19:55:50Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2025-07-10T19:55:50Z"]},{"key":"dc:date.issued","label":"Date","values":["2016-06-23"]},{"key":"dc:publisher","label":"Institution","values":["The University of Western Ontario"]},{"key":"dc:type","label":"Dc Type","values":["thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Physiology and Pharmacology"]},{"key":"thesis:degree_name","label":"Degree Name","values":["M Sc"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Gap junction channel","unitary conductance","Mg2+-dependent modulation","patch clamp","electrostatics"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en_ca"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://hdl.handle.net/20.500.14721/33820"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["The thesis cover page in the PDF document includes references to Western University’s previous institutional repository platform, known as Scholarship@Western, and links to that platform (beginning with ir.lib.uwo.ca). In citing or referring to this thesis, use the DOI or handle from this page instead. Sample citation: Author name, \"Thesis title.\" (Year). Western University Open Repository. https://doi.org/10.71858/123456."]},{"key":"dc:description.abstract","label":"Abstract","values":["Gap junction channels (GJs) are oligomers of connexins forming channels linking neighbouring cells. GJs formed by different connexins show distinct unitary channel conductance (γj), transjunctional-voltage dependent gating (Vj-gating) properties, and magnesium modulation. We investigate here how pore-lining residues may influence these GJ properties. We mutated putative pore-lining residues in Cx50 GJ (G8E/G46E/V53E individually or in combination) to investigate γj, Vj-gating, and magnesium modulation. GJs formed by combination mutants (G8E-G46E, G46E-V53E, and G8E-G46E-V53E) were functional and showed a significantly increased γj with little change in Vj-gating, while G8E-V53E mutants failed to form functional GJs. The γjs of the mutant GJs were reduced up to 30% by inclusion of magnesium in intracellular solution. Studying the individual mutations revealed that magnesium-dependent reduction of γj are due to one or combinations of V53E and/or G46E. Increasing negatively charged glutamate residues at 53rd and/or 46th positions of Cx50 increased magnesium-sensitive ion permeation."]},{"key":"dc:title","label":"Title","values":["Putative Pore-lining Residues and Intracellular Magnesium Influence Connexin50 Unitary Gap Junction Channel Conductance"]}]}],"canonical_facts":{"dc:contributor.advisor":["Bai, Donglin"],"dc:creator":["Sudhakar, Swathy"],"dc:date.accessioned":["2025-07-10T19:55:50Z"],"dc:date.available":["2025-07-10T19:55:50Z"],"dc:date.issued":["2016-06-23"],"dc:description":["The thesis cover page in the PDF document includes references to Western University’s previous institutional repository platform, known as Scholarship@Western, and links to that platform (beginning with ir.lib.uwo.ca). In citing or referring to this thesis, use the DOI or handle from this page instead. Sample citation: Author name, \"Thesis title.\" (Year). Western University Open Repository. https://doi.org/10.71858/123456."],"dc:description.abstract":["Gap junction channels (GJs) are oligomers of connexins forming channels linking neighbouring cells. GJs formed by different connexins show distinct unitary channel conductance (γj), transjunctional-voltage dependent gating (Vj-gating) properties, and magnesium modulation. We investigate here how pore-lining residues may influence these GJ properties. We mutated putative pore-lining residues in Cx50 GJ (G8E/G46E/V53E individually or in combination) to investigate γj, Vj-gating, and magnesium modulation. GJs formed by combination mutants (G8E-G46E, G46E-V53E, and G8E-G46E-V53E) were functional and showed a significantly increased γj with little change in Vj-gating, while G8E-V53E mutants failed to form functional GJs. The γjs of the mutant GJs were reduced up to 30% by inclusion of magnesium in intracellular solution. Studying the individual mutations revealed that magnesium-dependent reduction of γj are due to one or combinations of V53E and/or G46E. Increasing negatively charged glutamate residues at 53rd and/or 46th positions of Cx50 increased magnesium-sensitive ion permeation."],"dc:identifier.uri":["https://hdl.handle.net/20.500.14721/33820"],"dc:language.iso":["en_ca"],"dc:publisher":["The University of Western Ontario"],"dc:subject":["Gap junction channel","unitary conductance","Mg2+-dependent modulation","patch clamp","electrostatics"],"dc:title":["Putative Pore-lining Residues and Intracellular Magnesium Influence Connexin50 Unitary Gap Junction Channel Conductance"],"dc:type":["thesis"],"thesis:degree_discipline":["Physiology and Pharmacology"],"thesis:degree_name":["M Sc"]},"updated_at":"2026-07-27T21:55:56Z"}