Collagen alpha-2(IV) chain
Domain
Alpha chains of type IV collagen have a non-collagenous domain (NC1) at their C-terminus, frequent interruptions of the G-X-Y repeats in the long central triple-helical domain (which may cause flexibility in the triple helix), and a short N-terminal triple-helical 7S domain.
Function
Type IV collagen is the major structural component of glomerular basement membranes (GBM), forming a 'chicken-wire' meshwork together with laminins, proteoglycans and entactin/nidogen.
Canstatin, a cleavage product corresponding to the collagen alpha 2(IV) NC1 domain, possesses both anti-angiogenic and anti-tumor cell activity. It inhibits proliferation and migration of endothelial cells, reduces mitochondrial membrane potential, and induces apoptosis. Specifically induces Fas-dependent apoptosis and activates procaspase-8 and -9 activity. Ligand for alphavbeta3 and alphavbeta5 integrins.
Involvement in disease
Brain small vessel disease 2
BSVD2
An autosomal dominant cerebrovascular disorder with variable manifestations reflecting the location and severity of the vascular defect. BSVD2 features include intracranial hemorrage, fluid-filled cysts or cavities within the cerebral hemispheres, delayed psychomotor development, hemiplegia, spasticity and seizures.
None
The disease is caused by variants affecting the gene represented in this entry.
Intracerebral hemorrhage
ICH
A pathological condition characterized by bleeding into one or both cerebral hemispheres including the basal ganglia and the cerebral cortex. It is often associated with hypertension and craniocerebral trauma. Intracerebral bleeding is a common cause of stroke.
None
Disease susceptibility is associated with variants affecting the gene represented in this entry.
Post-translational modifications
Prolines at the third position of the tripeptide repeating unit (G-X-Y) are hydroxylated in some or all of the chains.
Type IV collagens contain numerous cysteine residues which are involved in inter- and intramolecular disulfide bonding. 12 of these, located in the NC1 domain, are conserved in all known type IV collagens.
The trimeric structure of the NC1 domains is stabilized by covalent bonds between Lys and Met residues.
Proteolytic processing produces the C-terminal NC1 peptide, canstatin.
Sequence Similarities
Belongs to the type IV collagen family.
Cellular localization
- Secreted
- Extracellular space
- Extracellular matrix
- Basement membrane
Alternative names
Collagen alpha-2(IV) chain, COL4A2