Collagen, type IV, alpha 5

Collagen, Type IV, Alpha 5

Collagen, type IV, alpha 5 is a protein that is encoded by the COL4A5 gene in humans. It is a crucial component of the basement membrane, a specialized structure that supports and separates epithelial and endothelial cells from the underlying connective tissue. Type IV collagen is unique among collagens in that it forms a network rather than fibrils, providing structural support and playing a role in filtration processes.

Structure

Collagen type IV is composed of three alpha chains that form a triple helix. The alpha 5 chain, encoded by the COL4A5 gene, is one of six genetically distinct alpha chains (alpha 1 to alpha 6) that can form type IV collagen. The alpha 5 chain typically pairs with alpha 3 and alpha 4 chains to form the Goodpasture antigen-binding protein, which is a component of the glomerular basement membrane in the kidneys.

Function

The primary function of collagen type IV is to provide structural integrity to basement membranes. It plays a critical role in the filtration barrier of the kidney glomeruli, the blood-brain barrier, and other specialized basement membranes throughout the body. The alpha 5 chain is particularly important in the kidney and cochlea, where it contributes to the function of the glomerular basement membrane and the inner ear, respectively.

Clinical Significance

Mutations in the COL4A5 gene are associated with Alport syndrome, a genetic disorder characterized by progressive kidney disease, hearing loss, and eye abnormalities. Alport syndrome is typically inherited in an X-linked manner, as the COL4A5 gene is located on the X chromosome. Males are more severely affected due to having only one X chromosome, while females may be carriers with milder symptoms.

Research and Therapeutic Approaches

Research into collagen type IV, alpha 5, focuses on understanding its role in basement membrane biology and its involvement in diseases like Alport syndrome. Therapeutic approaches are being explored, including gene therapy, to correct or compensate for the defective COL4A5 gene.

Also see

• Collagen
• Basement membrane
• Alport syndrome
• Goodpasture syndrome
• Glomerular basement membrane

Collagen
Overview
Type	Protein
Function	Structural component of connective tissues
Location	Skin, tendons, ligaments, cartilage, bone, blood vessels
Types
Type I collagen Type II collagen Type III collagen Type IV collagen Type V collagen
Related Topics
Collagen synthesis Collagen diseases Collagen supplements Collagen fibers
See Also
Elastin Glycosaminoglycan Fibroblast Extracellular matrix