Abstract
Gap junction channels are composed of two apposing hemichannels (connexons) in the contiguous cells and provide a direct pathway for electrical and metabolic signaling between adjacent cells. The family of connexin genes comprises 20 members in the mouse and 21 genes in the human genome. Connexins are expressed in all tissues except differentiated skeletal muscle, erythrocytes, and mature sperm cells. Various tissues express more than one type of connexins; therefore, homotypic, heterotypic, and heteromeric gap junction channels may form between cells. In this article, we briefly review basic gating and permeability properties of homotypic and heterotypic gap junction channels as well as recent achievements in the research of their regulation by transjunctional voltage, intracellular calcium, pH, and phosphorylation.
Highlights
Structure of connexin gap junction channels Gap junction (GJ) channels provide a direct pathway for electrical and metabolic signaling between adjacent cells [11,12,13,14]
Heterotypic gap junction channels Since various tissues express more than one type of connexins, homotypic, heterotypic, and heteromeric GJ channels may form between cells
A recent study [158] has examined single-channel permeabilities of homotypic and heterotypic GJ channels formed of all known cardiac connexins, mCx30.2, Cx40, Cx43, and Cx45, to fluorescent dyes Lucifer yellow (LY) and Alexa Fluor (AF)
Summary
Gap junction channels are composed of two apposing hemichannels (connexons) in the contiguous cells and provide a direct pathway for electrical and metabolic signaling between adjacent cells. Various tissues express more than one type of connexins; homotypic, heterotypic, and heteromeric gap junction channels may form between cells. Connexins and innexins possess 3 or 2 cysteines in each extracellular loop, respectively, and form hemichannels and gap junction channels. Structure of connexin gap junction channels GJ channels provide a direct pathway for electrical and metabolic signaling between adjacent cells [11,12,13,14]. Expression of Cx40, Cx43, Cx45 together with Cx37 has been reported in blood vessels, with most abundant expression of Cx40 in endothelial cells and Cx43 in smooth muscle cells [47]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
