Gap junction protein delta 3 (GJD3)

Gap junction protein delta 3 (GJD3, also known as connexin-31.9 or CX31.9) is a member of the connexin family of ion channels essential for forming gap junctions, which are intercellular channels enabling direct cytoplasmic communication between adjacent cells. Each gap junction is assembled from two connexons, themselves hexamers of connexin monomers, allowing diffusion of small molecules and ions. GJD3 is predominantly expressed in the cardiac conduction system of mice, especially within the atrioventricular (AV) node, where it forms low-conductance channels that modulate AV conduction delay and cardiac impulse propagation. Experimental deletion in mice accelerates AV conduction, demonstrating its physiological role. In humans, GJD3 expression is low or undetectable in the conduction system, and its precise function remains unclear due to limited data and species-specific differences. No approved drugs or therapeutic agents specifically target GJD3, and current research focuses on its molecular biology and regulatory circuits. While perturbations in connexin family proteins are known to contribute to several cardiac and neurological diseases, GJD3's direct clinical relevance is limited. Safety and biomarker data exist only for research, not for clinical translation.

Other names

CX31.9Cx31.9Connexin-31.9Cx30.2GJA11GJC1Gap junction alpha-11 proteinGap junction chi-1 proteinGap junction delta-3 proteinGap junction protein, delta 3, 31.9kDa

Drugs acting on gap junctions or general connexin family members typically modulate intercellular communication or cardiac conduction, but mechanisms targeting GJD3 directly are not established.