Eps15R and clathrin regulate EphB2-mediated cell repulsion

Cell repulsion is a key process in tissue organization and morphogenesis. EphB receptors and ephrinB ligands are transmembrane proteins that mediate this repulsion when they interact. However, the mechanism by which this interaction leads to repulsion is not fully understood. Trans-endocytosis of the EphB-ephrinB complex is essential for the process. Prior research has shown that this trans-endocytosis is necessary for repulsion to occur. However, the specific proteins involved in this process remain unclear. No prior work had resolved the molecular players in EphB-mediated trans-endocytosis. This gap motivated the current investigation into the role of Eps15R and clathrin. Understanding this mechanism could provide insights into developmental biology and cancer progression. The study aims to clarify the role of these proteins in EphB2-mediated cell repulsion.

The study aimed to determine whether Eps15R and clathrin regulate EphB2-mediated cell repulsion. The researchers focused on the EphB2 and ephrinB1 proteins, which are known to mediate repulsion through trans-endocytosis. The specific problem addressed was the lack of understanding of the molecular mechanism behind this process. The motivation for the study was to identify the proteins involved in trans-endocytosis of the EphB2-ephrinB1 complex. The researchers hypothesized that Eps15R and clathrin might be key players in this mechanism. They used colorectal cell lines to test their hypothesis. The study sought to clarify the role of Eps15R and clathrin in this process. The ultimate goal was to provide evidence for their involvement in EphB2-mediated repulsion.

The researchers used Co115 colorectal cell lines stably expressing EphB2 and ephrinB1. They performed co-culture experiments to observe cell repulsion. Knockdown of Eps15R and Eps15 was used to assess their roles in the process. Cell repulsion was measured in co-cultures of EphB2- and ephrinB1-expressing cells. A novel interaction motif in Eps15R was identified through in vitro binding assays. The DPFxxLDPF motif was shown to bind the clathrin terminal domain. A rescue experiment was conducted to test the role of Eps15R in repulsion. Wild-type Eps15R was compared to a clathrin-binding mutant in the co-culture assay.

Knockdown of Eps15R significantly reduced cell repulsion in co-cultures. In contrast, knockdown of Eps15 had no effect on repulsion. The DPFxxLDPF motif in Eps15R was found to bind directly to clathrin in vitro. The interaction between Eps15R and clathrin was shown to be necessary for repulsion. In the rescue experiment, wild-type Eps15R restored cell repulsion. The clathrin-binding mutant of Eps15R failed to rescue repulsion. These results suggest that Eps15R and clathrin are required for EphB2-mediated repulsion. The findings provide the first evidence that these proteins control trans-endocytosis of the EphB2-ephrinB1 complex.

The study provides evidence that Eps15R and clathrin regulate EphB2-mediated cell repulsion. The DPFxxLDPF motif in Eps15R is essential for binding to clathrin. This interaction is necessary for the trans-endocytosis of the EphB2-ephrinB1 complex. Knockdown of Eps15R, but not Eps15, reduces cell repulsion. The rescue experiment supports the role of Eps15R and clathrin in this process. The findings suggest that Eps15R and clathrin are key players in EphB2-mediated repulsion. The study contributes to understanding the molecular mechanism of trans-endocytosis. The results may have implications for developmental biology and cancer research.