Collagen type XVIII alpha 1 chain (COL18A1)

Collagen type XVIII alpha 1 chain is a structural protein encoded by the COL18A1 gene and forms an essential component of basement membranes throughout the body. It is part of the multiplexin family and exists in three isoforms due to alternative splicing. Proteolytic cleavage of its non-collagenous C-terminal domain produces endostatin, a soluble, potent endogenous inhibitor of angiogenesis. Collagen XVIII is critical for tissue architecture, particularly in the eye, where its deficiency causes Knobloch syndrome with ocular and neurological defects. Endostatin blocks blood vessel formation, thus regulating tumor growth and making COL18A1—via the endostatin fragment—a major therapeutic target in cancer. Pathogenic mutations cause loss of function disorders, mostly affecting the retina and occipital bone. In summary, COL18A1 is both a key ECM structural protein and an antiangiogenic precursor, with roles in cancer, congenital eye disease, and vascular biology.

Other names

Collagen alpha-1(XVIII) chainEndostatinNon-collagenous domain 1 (NC1)KNOKNO1KSGLCCMulti-functional protein MFPcollagen, type XVIII, alpha 1FLJ27325FLJ34914MGC74745

Inhibition of angiogenesis: Endostatin binds endothelial cells, blocks pro-angiogenic signaling, and causes cell cycle arrest, reducing new blood vessel formation; Tumor growth inhibition by limiting tumor vascularization