Interferon Induced Transmembrane Protein 1 (IFITM1)

IFITM1 is a member of the IFITM family which is encoded by IFITM genes. The human IFITM genes locate on chromosome 11 and have four members: IFITM1, IFITM2, IFITM3 and IFITM5. While the mouse Ifitm genes locate on chromosome 7 and 16 and have six members: Ifitm1, Ifitm2, Ifitm3, Ifitm5, Ifitm6 and Ifitm7. IFITM proteins have a short N-terminal and C-terminal domain, two transmembrane domains (TM1 and TM2) and a short cytoplasmic domain. The first transmembrane domain (TM1) and the cytoplasmic domain are conserved among different IFITM proteins in human and mouse. In the absence of interferon stimulation, IFITM proteins can express broadly in tissues and cell lines. In human, ITITM1, IFITM2 and IFITM3 are able to express in different tissues and cells while the expression of IFITM5 is limited to osteoblasts.