Aliases for GJB2 Gene
External Ids for GJB2 Gene
Previous HGNC Symbols for GJB2 Gene
Previous GeneCards Identifiers for GJB2 Gene
This gene encodes a member of the gap junction protein family. The gap junctions were first characterized by electron microscopy as regionally specialized structures on plasma membranes of contacting adherent cells. These structures were shown to consist of cell-to-cell channels that facilitate the transfer of ions and small molecules between cells. The gap junction proteins, also known as connexins, purified from fractions of enriched gap junctions from different tissues differ. According to sequence similarities at the nucleotide and amino acid levels, the gap junction proteins are divided into two categories, alpha and beta. Mutations in this gene are responsible for as much as 50% of pre-lingual, recessive deafness. [provided by RefSeq, Oct 2008]
GeneCards Summary for GJB2 Gene
GJB2 (Gap Junction Protein, Beta 2, 26kDa) is a Protein Coding gene. Diseases associated with GJB2 include deafness, autosomal dominant 3a and keratoderma, palmoplantar, with deafness. Among its related pathways are Clathrin derived vesicle budding and Myometrial Relaxation and Contraction Pathways. GO annotations related to this gene include gap junction channel activity. An important paralog of this gene is GJB3.
UniProtKB/Swiss-Prot for GJB2 Gene
One gap junction consists of a cluster of closely packed pairs of transmembrane channels, the connexons, through which materials of low MW diffuse from one cell to a neighboring cell
Gap channels (also known as gap junctions) are specalized cell-cell contacts between almost all eukaryotic cells that provide direct intracellular communication. Generally, gap channels allow the passive diffusion of molecules up to 1 kDa which includes nutrients, small metabolites (e.g. glucose), ions (K+, Ca2+) and second messengers (IP3, cAMP and cGMP). Gap channels allow electrical and biochemical coupling between cells and in excitable tissues, such as neurons and the heart, enables the generation of synchronized and rapid responses. Structurally, gap channels are composed of two hemichannels called 'connexons', which themselves are formed from six connexin molecules. Homo- and heteromeric combinations are seen, which exhibit distinct permeability, selectivity and functional properties. Pannexins are related to connexins and can also form gap junctions. However, their expression is limited to the brain. Furthermore, in nonchordate animals a family of proteins called innexins form these channels. Gap channels are regulated through post-translational modifications of the C'-terminal cytoplasmic tail and phosphorylation modulates assembly and their physiological properties. They are continuously synthesized and degraded, allowing tissues to rapidly adapt to changing environmental conditions. Connexins play a key role in many physiological processes including cardiac and smooth muscle contraction, regulation of neuronal excitability, epithelial electrolyte transport and keratinocyte differentiation. Mutations in connexin genes are associated with human diseases including sensorineural deafness, a variety of skin disorders, peripheral neuropathy and cardiovascular disease.