Decorin

Decorin is a small secreted chondroitin/dermatan sulfate proteoglycan in the family of small leucine-rich proteoglycans (SLRPs) . SLRP family members are characterized by N-terminal and C-terminal cysteine rich regions which flank the central region containing 10-12 tandem leucinerich repeats (LRR) . The human Decorin cDNA encodes a 359 amino acid (aa) precursor that includes a 16 aa signal sequence and a 14 aa propeptide. The 329 aa mature protein contains twelve LRR. Alternate splicing generates five isoforms with variable length deletions. Mature human and mouse Decorin share 80% aa sequence identity. In Decorin, serine 34 in the N-terminal domain is O-glycosylated. Naturally occurring Decorin proteoglycan has a molecular mass of approximately 100 kDa, and the deglycosylated Decorin core protein has a mass of approximately 40 kDa. Decorin binds to fibronectin, TGFβ, and type I and type II collagens. The binding of Decorin to various molecules was reported to be mediated via the core protein. Decorin has been implicated in matrix assembly and has also been reported to suppress the growth of various tumor cell lines by activating the epidermal growth factor receptor.