GJA3: 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. Defects in GJA3 are the cause of cataract zonular pulverulent cataract type 3 (CZP3). A form of zonular cataract. Zonular or lamellar cataracts are opacities, broad or narrow, usually consisting of powdery white dots affecting only certain layers or zones between the cortex and nucleus of an otherwise clear lens. The opacity may be so dense as to render the entire central region of the lens completely opaque, or so translucent that vision is hardly if at all impeded. Zonular cataracts generally do not involve the embryonic nucleus, though sometimes they involve the fetal nucleus. Usually sharply separated from a clear cortex outside them, they may have projections from their outer edges known as riders or spokes. Defects in GJA3 are a cause of cataract autosomal dominant (ADC). Cataract is an opacification of the crystalline lens of the eye that frequently results in visual impairment or blindness. Opacities vary in morphology, are often confined to a portion of the lens, and may be static or progressive. In general, the more posteriorly located and dense an opacity, the greater the impact on visual function. Belongs to the connexin family. Alpha-type (group II) subfamily.
Protein type: Membrane protein, integral; Membrane protein, multi-pass
Chromosomal Location of Human Ortholog: 13q12.11
Cellular Component: connexon complex; integral to membrane; lipid raft
Molecular Function: gap junction channel activity; identical protein binding
Biological Process: cell-cell signaling; response to hydrogen peroxide; response to pH; transmembrane transport; transport; visual perception
Disease: Cataract 14, Multiple Types
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