GJA5

GJA5 encodes connexin 40 (Cx40), also known as gap junction alpha-5 protein. It assembles into hexameric connexons that form gap junction channels, mediating intercellular transfer of ions, small metabolites, and signaling molecules (e.g., cAMP). This function is critical for synchronized electrical activity in cardiac tissues like the atria.
Pathogenic GJA5 mutations disrupt channel formation or function, contributing to atrial fibrillation and congenital heart defects. Drug development focuses on gap junction modulators to restore Cx40-mediated communication; however, most candidates are in preclinical stages, with ongoing research to validate their efficacy in correcting cardiac electrical abnormalities.