Gap junction protein alpha-5 (connexin-40) (Cx40)

Gap junction protein alpha-5 (connexin-40) is a transmembrane ion channel subunit of the connexin protein family that forms gap junctions—specialized intercellular channels allowing direct diffusion of ions, metabolites, and small signaling molecules between neighboring cells. This protein is highly expressed in cardiac atrial myocytes and vascular endothelial cells, where it is essential for electrical conduction and synchronization of tissue function. Its tightly regulated expression maintains the electrophysiologic and structural integrity of the cardiovascular system. Mutations or dysregulation of GJA5 have been identified in familial and idiopathic atrial fibrillation and in congenital heart defects involving the cardiac conduction system and great vessels.

Other names

Connexin-40Cx40GJA5ATFB11gap junction protein alpha 5 40 kDaGap junction alpha-5 proteinCX40

Competitive or non-competitive inhibition of gap junction channels, leading to reduced cell-cell coupling and altered cardiac electrical conduction.