Cysteine Rich Protein, Angiogenic Inducer 61 (CYR61)

CYR61 is a secreted, cysteine-rich, heparin-binding protein encoded by a growth factor-inducible immediate-early gene. Acting as an extracellular, matrix-associated signaling molecule, CYR61 promotes the adhesion of endothelial cells through interaction with integrin and augments growth factor-induced DNA synthesis in the same cell type.

The transcription of immediate-early genes is induced rapidly when cells are stimulated by growth factors or transforming oncogenes.The human CYR61 gene encodes a predicted 382-amino acid protein that is 93% identical to the mouse protein, and contains 10% cysteine residues and a 24-amino acid N-terminal signal sequence. Northern blot analysis revealed 2.5-kb and minor 4-kb CYR61 mRNAs that are expressed widely at varying levels.