Src homology 3 domain of SAM And SH3 Domain Containing Protein 1
SASH1 is a potential tumor suppressor in breast and colon cancer. Its decreased expression is associated with aggressive tumor growth, metastasis, and poor prognosis. It is widely expressed in normal tissues (except lymphocytes and dendritic cells) and is localized in the nucleus and the cytoplasm. SASH1 interacts with the oncoprotein cortactin and is important in cell migration and adhesion. It is a member of the SLY family of proteins, which are adaptor proteins containing a central conserved region with a bipartite nuclear localization signal (NLS) as well as SAM (sterile alpha motif) and SH3 domains. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.