Gap junction beta-1 protein (GJB1)

Gap junction beta-1 protein (GJB1), also known as connexin 32 (Cx32), is a member of the connexin family of transmembrane proteins that assemble to form gap junctions—specialized intercellular channels allowing passive diffusion of ions, small metabolites, and signaling molecules between adjacent cells[1][2][3]. These channels are crucial for cell–cell communication in the peripheral and central nervous systems, liver, pancreas, and kidney. GJB1 is most functionally important in Schwann cells and oligodendrocytes, where its proper assembly and localization support the structural and functional maintenance of myelin sheaths[1][2][4]. Mutations in GJB1 cause X-linked Charcot-Marie-Tooth disease (CMTX1), a hereditary neuropathy characterized by progressive distal muscle weakness and atrophy, sensory loss, and slowed nerve conduction, attributed to defective intercellular signaling and myelin pathology[1][2][3][4]. GJB1 function is essential for electrical and metabolic coupling in myelinated nerves, and loss of function or trafficking defects in this protein have been linked to neurological disease[4]. There are no established direct pharmacological agents that modulate GJB1/connexin 32 as a therapeutic target, although the gene/protein is a key biomarker for diagnosing CMTX1[2][4].

Other names

Connexin 32Cx32CX32GAP junction 28 kDa liver proteinCharcot-Marie-Tooth neuropathy, X-linkedconnexin-32CMTXCMTX1gap junction protein, beta 1, 32 kDa

Not applicable for direct drug therapies; all current disease associations (CMTX) are due to loss-of-function mutations or altered channel function, not modulated therapeutically.