DDR1 autophosphorylation is a result of aggregation into dense clusters

Abstract

The collagen receptor DDR1 is a receptor tyrosine kinase that promotes progression of a wide range of human disorders. Little is known about how ligand binding triggers DDR1 kinase activity. We previously reported that collagen induces DDR1 activation through lateral dimer association and phosphorylation between dimers, a process that requires specific transmembrane association. Here we demonstrate ligand-induced DDR1 clustering by widefield and super-resolution imaging and provide evidence for a mechanism whereby DDR1 kinase activity is determined by its molecular density. Ligand binding resulted in initial DDR1 reorganisation into morphologically distinct clusters with unphosphorylated DDR1. Further compaction over time led to clusters with highly aggregated and phosphorylated DDR1. Ligand-induced DDR1 clustering was abolished by transmembrane mutations but did not require kinase activity. Our results significantly advance our understanding of the molecular events underpinning ligand-induced DDR1 kinase activity and provide an explanation for the unusually slow DDR1 activation kinetics.

A two-site flexible clamp mechanism for RET-GDNF-GFRα1 assembly reveals both conformational adaptation and strict geometric spacing

“…This interface was reported to influence the rate of receptor endocytosis. These findings suggest that a signalling-competent RET ECD conformation is likely to involve higher order multimers consistent with findings for other RTKs such as EphR (Seiradake et al, 2010) EGFR (Needham et al, 2016) and DDR1 (Corcoran et al, 2019) RTKs. Therefore, a crucial aspect of receptor activation beyond the positioning of the RET transmembrane regions within a dimeric assembly is their arrangement within higher order clusters.…”

MRIP Regulates the Myosin IIA Activity and DDR1 Function to Enable Collagen Tractional Remodeling

“…Recently we and others identified a link between collagen-induced DDR1 clustering and the activation of the cytoplasmic kinase domain of DDR1 by phosphorylation of tyrosine 792 (Y792). This process then leads to phosphorylation of Y513 in neighboring dimers [ 9 , 10 ]. We found that cells expressing kinase-depleted DDR1d, or cells expressing kinase-dead DDR1e, or cells expressing DDR1b but cultured on non-activating fibronectin substrates, formed fewer and smaller clusters compared with cells expressing full-length kinase active DDR1b that were cultured on collagen.…”

“…We considered that collagen-induced DDR1 clustering induces DDR1 activation. This activation reinforces DDR1 binding to collagen that may involve a feedforward mechanism that increases receptor clustering [ 10 ]. Initial DDR1 clustering is not sufficient for DDR1 activation and DDR1 kinase activity is only triggered when DDR1 aggregates into dense clusters [ 11 ].…”

“…This process generates a positive feedback loop. In turn, the feedback loop strengthens cell adhesion and optimizes the transmission of NMIIA-dependent contractile forces to collagen fibrils [ 10 , 12 ]. Despite these advances, the mechanisms that regulate the transmission of NMIIA-generated forces through DDR1 are not defined.…”

Meeting report – first discoidin domain receptors meeting

“…However, DDR-dependent signalling is not initiated at the level of dimers, but rather upon formation of higher-order clusters; here, receptor activation can occur through interactions between neighbouring dimers. Using fluorescent imaging, she recently obtained evidence that ligandinduced DDR1 phosphorylation results from aggregation into dense signalling clusters (Juskaite et al, 2017;Corcoran et al, 2019) (Fig. 1).…”