Interferon Induced Protein 44 (IFI44)

The deduced 444-amino acid protein shares 97.5% identity with the chimpanzee protein.Northern blot analysis of RNA from PLC/PRF/5 human hepatoma-derived cells showed that IFI44 is inducible by interferon (IFN)-alpha and IFN-beta, but not by IFN-gamma. Functional analysis of the IFI44 promoter in PLC/PFR/5 cells showed that induction by interferons was mediated via the ISRE as mutations to this element prevented induction. IFI44 is induced in the liver of chimpanzees infected with hepatitis C or hepatitis D virus, but not in the liver of those infected with hepatitis B virus. induction is the result of interferons produced in response to viral infection.IFI44 gene contains 9 exons and spans approximately 14 kb. The first exon contains the 5-prime noncoding region of the mRNA.