Decorin

Decorin is a proteoglycan on average 90 - 140 kilodaltons (kD) in size.

It belongs to the small leucine-rich proteoglycan (SLRP) family and consists of a protein core containing leucine repeats with a glycosaminoglycan (GAG) chain consisting of either chondroitin sulfate (CS) or dermatan sulfate (DS).

Desmin is a small cellular or pericellular matrix proteoglycan and is closely related in structure to biglycan protein. Decorin and biglycan are thought to be the result of a gene duplication. This protein is a component of connective tissue, binds to type I collagen fibrils, and plays a role in matrix assembly.

Naming
Decorin's name is a derivative of both the fact that it "decorates" collagen, and that it interacts with the "d" and "e" bands.

Function
Decorin appears to influence fibrillogenesis, and also interacts with fibronectin, thrombospondin, the complement component C1q, epidermal growth factor receptor (EGFR) and transforming growth factor-beta (TGF-beta).

In some publications, decorin has been shown to enhance the bioactivity of TGF-beta 1, in other publications, TGF-beta 1's bioactivity has been shown to be inhibited. Because of this, it is believed the primary function of decorin lies in certain aspects of regulation during the cell cycle.

Infusion of decorin into experimental rodent spinal cord injuries has been shown to suppress scar formation and promote axon growth.

Decorin has been shown to have anti-tumorigenic properties in an experimental murine tumor model and is capable of suppressing the growth of various tumor cell lines. There are multiple alternatively spliced transcript variants known for the decorin gene. It is a candidate gene for Marfan syndrome.