Interferon-induced protein with tetratricopeptide repeats 1 (IFIT1)

Interferon-induced protein with tetratricopeptide repeats 1 (IFIT1) is a cytoplasmic, interferon-stimulated protein characterized by multiple tetratricopeptide repeat (TPR) motifs, enabling extensive protein–protein and protein–RNA interactions[1][4][5]. IFIT1 serves as a key effector in the innate antiviral immune response, potently inhibiting translation of viral RNAs by selectively binding to the 5′ end of RNA molecules lacking 2′-O methylation on the cap, a common feature of many viral RNAs but not host mRNAs[1][2][4]. This selectivity allows IFIT1 to distinguish non-self from self-RNAs, blocking synthesis of viral proteins and limiting infection[2][4]. IFIT1 can form complexes with other IFIT family members (notably IFIT2 and IFIT3), which further modifies its activity range and specificity[5]. The protein has rapid evolutionary divergence across mammals, reflecting ongoing adaptation to viral threats[3]. Beyond infection, IFIT1 and its complexes are being studied for roles in cancer biology and cell signaling[5]. No direct small-molecule drugs are known to target IFIT1 as of the latest literature, but its function is essential for a robust interferon-mediated response to viral and other pathogens[1][2][4][5].

Other names

Antiviral innate immune response effector IFIT1IFIT1G10P1IFI56ISG56IFIT-1IFI-56KP56GARG-16Interferon-induced 56 kDa proteinC56IFI-56IFNAI1RNM561Interferon, alpha-inducible protein (MW 56kD)Interferon-inducible mRNA 561

Inhibits translation of viral RNAs by binding to their 5′-unmethylated cap structures, blocking ribosome recruitment; Outcompetes eukaryotic initiation factor 4E (eIF4E)/eIF4F for RNA binding