MTSS1(metastasis suppressor protein 1, also known as MIM) is an I-BAR (Bin/amphipysin/Rvs) domain containing protein. BAR domain forms an anti-parallel all-helical dimer, with a curved (banana-like) shape, that promotes membrane tubulation. The BAR domain containing proteins can be classified into three types: BAR, F-BAR and I-BAR. BAR and F-BAR proteins generate positive membrane curvature, while I-BAR proteins induce negative curvature [].MIM also contains an additional C-terminal WH2 domain that binds G-actin. In mice MIM inhibits the nucleation of actin filaments in vitro []. In humans MIM may be related to cancer progression or tumour metastasis in a variety of organ sites, most likely through an interaction with the actin cytoskeleton []. MIM undergoes Src-dependent tyrosine phosphorylation, and this phosphorylation is important for actin remodelling []. MIM is also involved in the sonic hedgehog (Shh) signalling [].
