Various types of collagen have been identified as potential ligands for the two mammalian
discoidin domain receptor (DDR) tyrosine kinases, DDR1 and DDR2. It is presently unclear
whether collagen-induced DDR receptor activation, which occurs with very slow kinetics,
involves additional proteins with kinase activity or membrane-anchored proteins serving as
coreceptors. In particular, the role of the collagen-binding integrins α 1 β 1 or α 2 β 1 in the
DDR activation process is undefined. Here, we provide three lines of evidence suggesting …