Gap junction gamma-3 protein (GJC3)

Gap junction gamma-3 protein (GJC3), also known as Connexin-30.2 (Cx30.2), is a transmembrane protein that forms gap junction channels and hemichannels, facilitating direct intercellular communication (UniProt P57773). In humans, GJC3 is predominantly expressed in the specialized conduction system of the heart, specifically the atrioventricular (AV) node and the bundle of His, where it mediates low-conductance electrical coupling (Kreuzberg et al., 2006). This low conductance is essential for the physiological delay of electrical impulses between the atria and ventricles, ensuring coordinated cardiac contraction. The N-terminal domain of GJC3 is a critical structural component that lines the channel pore and is involved in voltage-dependent gating and channel selectivity (Bukauskas et al., 2006). Genetic variations in GJC3 have been associated with alterations in cardiac conduction, such as variations in the PR interval and susceptibility to arrhythmias (Schrickel et al., 2009). While no GJC3-specific drugs are currently approved, the protein is a target of interest for modulating cardiac rhythm, with experimental approaches utilizing non-specific gap junction blockers like carbenoxolone or domain-specific mimetic peptides (NCBI Gene ID: 349149).

Other names

Connexin-30.2Cx30.2GJC3Gap junction protein gamma 3Connexin-31.3 (mouse ortholog)

Inhibition of gap junctional intercellular communication and hemichannel activity by blocking the channel pore or preventing hexamer assembly.