Metastasis suppressor protein 1 (MTSS1) [MIM, “missing in metastasis”], was first discovered as missing transcripts from metastatic bladder and prostate cancer cells. MTSS1 is a 755 amino acid protein, having multidomain and scaffolding function. It has a proline-rich/SH3 binding region and a serine-rich region with EGF or PDGF/Src consensus sites. It contains an actin-binding Wiskott-Aldrich syndrome protein homology-2 motif (WH2) at the C-terminus while the N-terminal IMD domain (IRSp53-MIM domain) interact with membranes and bundle actin filament. The WH2 domain binds to actin monomers and plays an important role in actin cytoskeleton reorganization. Recently, MIM was found to interact with cortactin via SH3 domains. In addition, MTSS1 enhanced cortactin- and Arp2/3-dependent actin polymerization. It is thus involved in cell motility and morphogenesis and also interacts with sonic hedgehog/Gli signaling in epidermal cells. MTSS1 acts as an important regulator of cell growth and development and is known to express in many tissues, including spleen, thymus, prostate, testis, uterus, colon, and peripheral blood.
Metastasis suppressor protein 1; Metastasis suppressor YGL-1; MIM; MIMA; MIMB; Missing in metastasis protein; Protein MTSS 1