Connexin 40 (CX40)

Gap junction alpha-5 protein  is a component of gap junctions, which are composed of arrays of intercellular channels that provide a route for the diffusion of low molecular weight materials from cell to cell. Mutations in this gene may be associated with atrial fibrillation. Alternatively spliced transcript variants encoding the same isoform have been described.The CX40 gene encodes a predicted 358-amino acid protein whose sequence is 82% identical to that of the rat and mouse CX40 protein. Northern blot analysis showed that CX40 mRNA is expressed as an approximately 3.3-kb transcript in ventricular myocardium. In immunofluorescence studies, CX40 localized to intercalated disc regions of the left ventricle, which join cardiac myocytes and contain gap junctions.