Connexin 32

An overview of Connexin 32, its structure, function, and role in human health.

Connexin 32 (Cx32) is a protein that is encoded by the GJB1 gene in humans. It is a member of the connexin family, which are integral membrane proteins that form gap junctions in cells. Gap junctions are specialized intercellular connections that facilitate the direct transfer of ions and small molecules between neighboring cells, playing a crucial role in maintaining tissue homeostasis.

Structure

Connexin 32 is composed of four transmembrane domains, two extracellular loops, one intracellular loop, and cytoplasmic N- and C-termini. The protein assembles into hexameric structures known as connexons, which dock with connexons from adjacent cells to form a complete gap junction channel.

Function

Connexin 32 is predominantly expressed in the liver, pancreas, and nervous system, particularly in Schwann cells of the peripheral nervous system. It is essential for the proper functioning of these tissues by allowing the passage of ions and small metabolites, which is critical for cellular communication and metabolic cooperation.

Role in Disease

Mutations in the GJB1 gene, which encodes Connexin 32, are associated with X-linked Charcot-Marie-Tooth disease (CMTX), a hereditary neuropathy. CMTX is characterized by progressive muscle weakness and atrophy, sensory loss, and other neurological symptoms. The mutations disrupt the normal function of Connexin 32, leading to impaired nerve conduction and demyelination.

Research and Therapeutic Implications

Understanding the structure and function of Connexin 32 has significant implications for developing therapies for diseases like CMTX. Research is ongoing to explore gene therapy, small molecules, and other strategies to restore or compensate for the defective gap junction communication caused by Connexin 32 mutations.

Also see

• Gap junction
• Connexin
• Charcot-Marie-Tooth disease
• Schwann cell
• Peripheral nervous system