Discoidin domain receptors: multitaskers for physiological and pathological processes

Discoidin domain receptors 1 and 2 (DDR1 and DDR2) are key cellular receptors for cell-matrix interactions that belong to the family of receptor tyrosine kinases. Both DDRs interact with various collagens, with each DDR exhibiting specificity towards certain collagen types [1]. Like matrix-interacting integrins, the DDRs participate in cell adhesion and mechanosensing processes. Additionally, the DDRs play a role in cell-cell adhesion. Consequently, the DDRs can be used by cells to sense and control their microenvironments. In contrast to typical receptor tyrosine kinases that react quickly to ligand binding, the DDRs exhibit an intrinsic kinase activity with slow and prolonged activation [2