Connexin 40 (Cx40)

Connexin 40 (Cx40)is a tissue-specific gap junction protein. Gap junctions are important in providing cell to cell coupling for propagation of impulses within the myocardium. Cardiac connexin 40 expression is altered in atrial fibrillation. Promoter polymorphism with a G->A change at position -44 has been associated with atrial arrhythmias. A-allele at position -44 in promoter-reporter constructs reduces promoter activity significantly [Firouzi M, et al. The human Cx40 promoter polymorphism -44G->A differentially affects transcriptional regulation by Sp1 and GATA4. Biochim Biophys Acta. 2006;1759:491-6]. Those who are homozygous for the minor allele are termed AA while those who are heterozygous are designated as AG. GG is the notation for non carriers.