Type IV collagen

Type IV Collagen

Crystal structure of the collagen triple helix model.

Type IV collagen is a type of collagen found primarily in the basement membrane of various tissues. Unlike other types of collagen, which form fibrillar structures, type IV collagen forms a network that provides structural support and filtration functions in the basement membrane.

Structure

Type IV collagen is unique among collagens due to its non-fibrillar structure. It forms a network through the interaction of its triple-helical domains and non-collagenous domains. The molecule consists of three alpha chains, which form a triple helix. The non-collagenous (NC1) domain at the C-terminus is crucial for the assembly of the collagen network.

Function

Type IV collagen is a major component of the basement membrane, where it provides structural support and acts as a barrier to the passage of cells and large molecules. It plays a critical role in tissue development and repair, as well as in the filtration processes of the glomerulus in the kidney.

Fenestrated capillary showing basement membrane.

Clinical Significance

Mutations in the genes encoding type IV collagen can lead to several genetic disorders. For example, mutations in the COL4A5 gene are associated with Alport syndrome, a condition characterized by kidney disease, hearing loss, and eye abnormalities. Type IV collagen is also implicated in the pathogenesis of Goodpasture syndrome, an autoimmune disease affecting the lungs and kidneys.

Role in Disease

Type IV collagen is involved in various pathological conditions. In cancer, alterations in the basement membrane can facilitate tumor invasion and metastasis. In diabetes mellitus, changes in the composition and structure of the basement membrane can lead to complications such as diabetic nephropathy.

Coronary artery plaque, where basement membrane integrity is crucial.

Related Pages

• Collagen
• Basement membrane
• Alport syndrome
• Goodpasture syndrome
• Diabetic nephropathy