Interferon-induced transmembrane protein 1 (IFITM1)

Interferon-induced transmembrane protein 1 (IFITM1) is a small, intrinsic membrane protein encoded by the human IFITM1 gene, also known as CD225 among other names[1]. It is a member of the IFITM family, defined by two hydrophobic domains with at least one functioning as a transmembrane region, and is highly conserved across species[1][7]. IFITM1 is broadly expressed in human tissues, regulated predominantly by type I and II interferons, and is involved in antiviral defense by blocking an early step in the entry of many enveloped viruses—including respiratory syncytial virus, herpes simplex virus 1, and Epstein–Barr virus—by modifying host cell membrane properties or receptor accessibility[2][3][5]. Beyond antiviral immunity, IFITM1 has roles in cancer biology, promoting or inhibiting cell proliferation, migration, angiogenesis, and maintenance of cancer stemness in a context-dependent manner, frequently acting as a prognostic biomarker or a candidate target for therapy in oncology and immunotherapy settings[2][4][7]. There are currently no widely approved drugs targeting IFITM1, but its cell surface exposure and immunomodulatory roles make it an active focus in translational research[4][7].

Other names

CD225fragilisIFI17Interferon-induced protein 179-27Interferon-inducible protein 9-27Leu13

Inhibition of viral entry by alteration of membrane properties, Competitive inhibition of virus-receptor binding (e.g., blocks Epstein-Barr virus entry via competition with EphA2 receptor), Modulation of membrane fusion events