Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Physiology

Western University

Gap junction channel

Publication Year

Articles 1 - 4 of 4

Full-Text Articles in Life Sciences

The Amino Terminal Domains Of Sheep Cx46 Or Cx50 Determine Their Gap Junction Channel Open Stability And Unitary Channel Conductance, Benny Yue Jun 2020

The Amino Terminal Domains Of Sheep Cx46 Or Cx50 Determine Their Gap Junction Channel Open Stability And Unitary Channel Conductance, Benny Yue

Electronic Thesis and Dissertation Repository

Connexins form intercellular communication channels known as gap junctions (GJs), which are found throughout the vertebrate species. GJs formed by different connexins harbor unique channel properties that have not been fully defined. High-resolution structures of native Cx46 and Cx50 GJs from sheep (sCx46 and sCx50) were recently resolved. Molecular dynamics studies identified the NT domains, especially the 9th position, as key determinants in the differences of energetic barrier to K+ permeation in sCx46 and sCx50 GJs. We studied functional properties of GJs formed by sCx46, sCx50, NT domain swapped chimeras (sCx46-50NT and sCx50-46NT), and point variants at the …


Putative Pore-Lining Residues And Intracellular Magnesium Influence Connexin50 Unitary Gap Junction Channel Conductance, Swathy Sudhakar Jun 2016

Putative Pore-Lining Residues And Intracellular Magnesium Influence Connexin50 Unitary Gap Junction Channel Conductance, Swathy Sudhakar

Electronic Thesis and Dissertation Repository

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 …


Engineered Cx26 Variant Established Functional Heterotypic Cx26/Cx43 And Cx26/Cx40 Gap Junction Channels, Levent Berk Karademir Aug 2015

Engineered Cx26 Variant Established Functional Heterotypic Cx26/Cx43 And Cx26/Cx40 Gap Junction Channels, Levent Berk Karademir

Electronic Thesis and Dissertation Repository

Two hexameric connexin hemichannels dock together to from a whole gap junction (GJ) channel. The mechanisms of docking specificity in forming homotypic and heterotypic GJ channels are not fully clear. To reveal the key differences between Cx26 and Cx43 (or Cx40) in their docking residues, we aligned and analyzed ten well studied connexin sequences. Five of them are docking compatible with Cx26 and the rest (including Cx43 and Cx40) are not. According to Cx26 crystal structure at the docking interface, we identified two putative docking residues on the second extracellular domain (E2) that are well conserved within docking compatible connexins, …


Mutations At The 46th Residue Change Properties Of Cx50 Gap Junction Channels, Xiaoling Tong Aug 2014

Mutations At The 46th Residue Change Properties Of Cx50 Gap Junction Channels, Xiaoling Tong

Electronic Thesis and Dissertation Repository

The interface of the first transmembrane domain and the first extracellular loop (TM1/E1 border) in several gap junction (GJ) channels is known to line a portion of the pore and plays an important role in determining GJ channel properties. By introduction of a charged residue into this domain of Cx50, the resultant mutant channels showed drastically altered unitary conductance (γj) and transjunctional voltage-dependent gating (Vj-gating). Specifically G46D and G46E increased the Cx50 γj from 201 to 256 and 293 pS, respectively and G46K channel showed a decreased γj of only 20 pS. Moreover, in …