IFITM3/Fragilis Proteins and Enzymes

Mouse IFITM3/CD225 (also Fragilis) is a 137 amino acids (aa) 2-transmembrane protein that belongs to the Fragilis family of interferon-inducible genes. It contains two terminal extracellular domains (aas 1 - 57 and 131 - 137) and one cytoplasmic region that potentially allows for multiple phosphorylations. The N-terminal extracellular region of mouse IFITM3 is 54%, 91% and 58% aa identical to the equivalent region in bovine, rat and human IFITM3, respectively. IFITM3 is believed to be involved in primordial germ cell clustering and regionalization.