Discoidin domain receptors 1 and 2 (DDR1 and DDR2) are structurally-related membrane protein tyrosine kinases activated by collagen. Collagen is probably the most abundant protein in man, with at least 29 families of genes encoding proteins, which undergo splice variation and post-translational processing, and may exist in monomeric or polymeric forms, producing a triple-stranded, twine-like structure. In man, principal family members include COL1A1 (COL1A1, P02452), COL2A1 (COL2A1, P02458), COL3A1 (COL3A1, P02461) and COL4A1 (COL4A1, P02462).

The tyrosine kinase inhibitors of DDR, imatinib and nilotinib, were identified from proteomic analysis [1]. Other collagen receptors include glycoprotein VI (Q9HCN6), leukocyte-associated immunoglobulin-like receptor 1 (Q6GTX8), leukocyte-associated immunoglobulin-like receptor 2 (Q6ISS4) and osteoclast-associated immunoglobulin-like receptor (Q8IYS5).

1. Day E, Waters B, Spiegel K, Alnadaf T, Manley PW, Buchdunger E, Walker C, Jarai G. (2008) Inhibition of collagen-induced discoidin domain receptor 1 and 2 activation by imatinib, nilotinib and dasatinib. Eur J Pharmacol, 599 (1-3): 44-53. [PMID:18938156]