Spatially modulated ephrinA1:EphA2 signaling increases local contractility and global focal adhesion dynamics to promote cell motility

Abstract

Recent studies have revealed pronounced effects of the spatial distribution of EphA2 receptors on cellular response to receptor activation. However, little is known about molecular mechanisms underlying this spatial sensitivity, in part due to lack of experimental systems. Here, we introduce a hybrid live-cell patterned supported lipid bilayer experimental platform in which the sites of EphA2 activation and integrin adhesion are spatially controlled. Using a series of live-cell imaging and single-molecule tracking experiments, we map the transmission of signals from ephrinA1:EphA2 complexes. Results show that ligand-dependent EphA2 activation induces localized myosin-dependent contractions while simultaneously increasing focal adhesion dynamics throughout the cell. Mechanistically, Src kinase is activated at sites of ephrinA1:EphA2 clustering and subsequently diffuses on the membrane to focal adhesions, where it up-regulates FAK and paxillin tyrosine phosphorylation. EphrinA1:EphA2 signaling triggers multiple cellular responses with differing spatial dependencies to enable a directed migratory response to spatially resolved contact with ephrinA1 ligands.

Targeting the complexity of Src signalling in the tumour microenvironment of pancreatic cancer: from mechanism to therapy

“…The proto-oncogene tyrosine-protein kinase Src or cellular Src (c-Src) belongs to a family of nine nonreceptor tyrosine kinases that share similar structure and function [36]. Src kinase localises at cell-matrix adhesions, and is readily activated by positive migratory growth factor signalling, including, but not limited to, epidermal growth factor (EGF), hepatocyte growth factor (HGF), platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF) and integrin [37] and Eph receptor (EphA2) activation [38]. In turn, Src can phosphorylate substrates from numerous molecular pathways and consequently promotes tumour cell survival, proliferation, cell adhesion, migration, invasion and angiogenesis, key hallmarks of cancer ( Fig.…”

Helicobacter Pylori Targets the EPHA2 Receptor Tyrosine Kinase in Gastric Cells Modulating Key Cellular Functions

“…Overall, these results point to EPHA2 acting in a fashion compatible with that of an adhesion-like molecule, stressing its importance for epithelial monolayer integrity through cell-cell and cell-ECM interactions. The crosstalk between the EPHA2 receptor and integrins may be important not only for the inhibition of cell spreading and invasion, but also in cell-cell communication with epithelial cells and other cellular components of the stroma [77][78][79][80][81]. Furthermore, as globally observed in the angiogenesis array, in endothelial tube formation, and in CAM assays, EPHA2 promotes angiogenesis in response to H. pylori infection of gastric cells through the secretion or induction of angiogenic factors and through tumor cell-endothelium interactions.…”

More from less – bottom-up reconstitution of cell biology

“…These are just a few examples of how synthetic SLB-cell contacts have provided an easily-modifiable platform to study T-cell activation. Nevertheless, they illustrate that spatial reorganisation of receptorswhich do not only play an important role in T cell signallingcan be studied using a semireconstitution approach, including other immune cell interfaces , neuronal synapses (Pautot et al, 2005) and EphA2integrin signalling cross-talk in cell-cell adhesion (Chen et al, 2018).…”