COL4

COL4 is a type of collagen, a protein that is a major component of the extracellular matrix in the body. COL4, also known as type IV collagen, is specifically found in the basement membrane, a thin layer of extracellular matrix that separates epithelial cells and endothelial cells from underlying connective tissue.

Structure

COL4 is composed of three alpha chains, alpha-1(IV) and alpha-2(IV), which form a triple helix. Each alpha chain consists of a long Gly-X-Y repeat region, where X and Y are any amino acid, but often proline and hydroxyproline. This repeat region is responsible for the formation of the triple helix structure.

Function

The primary function of COL4 is to provide structural support to the basement membrane. It forms a network with other proteins, such as laminin and nidogen, to create a strong and flexible matrix. This network also plays a role in cell adhesion, migration, and differentiation.

Clinical significance

Mutations in the genes encoding the alpha chains of COL4 can lead to several diseases. For example, Alport syndrome is caused by mutations in the COL4A3, COL4A4, or COL4A5 genes. This syndrome is characterized by progressive kidney disease, hearing loss, and eye abnormalities. Another disease, Goodpasture syndrome, is an autoimmune disorder where the body's immune system attacks the COL4 in the kidneys and lungs.

See also

• Collagen, type IV, alpha 1
• Collagen, type IV, alpha 2
• Collagen, type IV, alpha 3
• Collagen, type IV, alpha 4
• Collagen, type IV, alpha 5
• Collagen, type IV, alpha 6