ADAM10 controls collagen signaling and cell migration on collagen by shedding the ectodomain of discoidin domain receptor 1 (DDR1).
Bottom Line: DDR1 shedding is not a result of an activation of its signaling pathway, since DDR1 mutants defective in signaling were shed in an efficient manner.DDR1 and ADAM10 were found to be in a complex on the cell surface, but shedding did not occur unless collagen bound to DDR1.Using a shedding-resistant DDR1 mutant, we found that ADAM10-dependent DDR1 shedding regulates the half-life of collagen-induced phosphorylation of the receptor.
Affiliation: Kennedy Institute of Rheumatology, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford OX3 7FY, United Kingdom.Show MeSH
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Mentions: We next examined the interaction between DDR1 and ADAM10 on the cell surface using in situ proximity ligation assay (PLA). PLA highlights two molecules within 40 nm of each other. As shown in Figure 5A, a bright PLA signal was detected in HEK293 cells stably expressing DDR1-NF, suggesting that DDR1 was indeed in a complex with endogenous ADAM10 on the cell surface. Some PLA signals were also detected in mock cells (Figure 5A, Mock). This is most likely due to expression of low levels of endogenous DDR1 in HEK293 cells. We next examined interaction of endogenous DDR1 and ADAM10 in A431 cells, using PLA (Figure 5B). Bright PLA signal was detected on the cell surface of A431 cells without collagen treatment, and the signals were notably reduced upon collagen treatment. This suggests that most of DDR1 in complex with ADAM10 has been shed and dissociated from ADAM10. The reduction of the signal was completely prevented by addition of Mst (Figure 5B, +Coll+Mst), supporting this notion. Although it is not clear whether ADAM10 and DDR1 directly interact with each other, these data suggest that they are at least in the same molecular complex on the cell surface.
Affiliation: Kennedy Institute of Rheumatology, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford OX3 7FY, United Kingdom.