COL4A3 Gene

The official name of COL4A3 gene is collagen, type IV, alpha 3 (Goodpasture antigen). COL4A3 gene provides instructions for making one component of type IV collagen. which is a flexible protein that forms complex networks. Specifically, this gene makes the alpha3(IV) chain of type IV collagen. This chain combines with two other types of alpha (IV) chains (the alpha4 and alpha5 chains) to make a complete collagen molecule. Type IV collagen networks make up a large portion of basement membranes, which are thin sheet-like structures that separate and support cells in many tissues. This specific type IV collagen network plays an especially important role in the basement membranes of the kidney, inner ear, and eye.

Function:

Type IV collagen, the major structural component of basement membranes, is a multimeric protein composed of 3 alpha subunits. These subunits are encoded by 6 different genes, alpha 1 through alpha 6, each of which can form a triple helix structure with 2 other subunits to form type IV collagen. This gene encodes alpha 3.In the Goodpasture syndrome, autoantibodies bind to the collagen molecules in the basement membranes of alveoli and glomeruli. The epitopes that elicit these autoantibodies are localized largely to the non-collagenous C-terminal domain of the protein.

Collagen

Location:

COL4A3 gene is present in human chromosome 2 and its coded from region 227,737,524 to base pair 227,887,750 with 52 exons, the cytogenetic location 2q36-q37

Disease

Mutations in this gene causes Alport syndrome,The autosomal recessive form of Alport syndrome results when two copies of the COL4A3 gene in each cell are mutated. Most of the mutations identified in this gene cause a change in the sequence of amino acids (the building blocks of proteins) in a region of the alpha3(IV) collagen chain that is critical for combining with other type IV collagen chains. Other mutations severely decrease or prevent the production of any alpha3(IV) chains in the basement membranes of the kidney, inner ear and eye. In the kidney, other types of collagen accumulate in the basement membranes, eventually leading to scarring of the kidneys and kidney failure. Mutations in this gene can also lead to abnormal function in the inner ear, resulting in hearing loss.