?
 
SAM domain of EPH-A4 subfamily of tyrosine kinase receptors SAM (sterile alpha motif) domain of EPH-A4 subfamily of receptor tyrosine kinases is a C-terminal potential protein-protein interaction domain. This domain is located in the cytoplasmic region of EPH-A4 receptors and appears to mediate cell-cell initiated signal transduction. SAM domains of EPH-A4 receptors can form homodimers. EPH-A4 receptors bind ligands such as erphirin A1, A4, A5. They are known to interact with a number of different proteins, including meltrin beta metalloprotease, Cdk5, and EFS2alpha, however SAM domain doesn't participate in these interactions. EPH-A4 receptors are involved in regulation of corticospinal tract formation, in pathway controlling voluntary movements, in formation of motor neurons, and in axon guidance (SAM domain is not required for axon guidance or for EPH-A4 kinase signaling). In Xenopus embryos EPH-A4 induces loss of cell adhesion, ventro-lateral protrusions, and severely expanded posterior structures. Mutations in SAM domain conserved tyrosine (Y928F) enhance the ability of EPH-A4 to induce these phenotypes, thus supporting the idea that the SAM domain may negatively regulate some aspects of EPH-A4 activity. EphA4 gene was found overexpressed in a number of different cancers including human gastric cancer, colorectal cancer, and pancreatic ductal adenocarcinoma. It is likely to be a promising molecular target for the cancer therapy. |
Jiyao W et al.(2023). "The conserved domain database in 2023.",