The ISG56/IFIT1 gene family.

The ISG56/IFIT1 family of genes is clustered on human chromosome 10 and is comprised of 4 members, ISG56/IFIT1, ISG54/IFIT2, ISG60/IFIT3, and ISG58/IFIT5, whose homologs are evolutionarily conserved from mammals to amphibians. While these genes are normally silent in most cell types, their transcription is strongly induced by interferons, virus infection, and molecular patterns such as double-stranded RNA or lipopolysaccharides. The encoded P56 family proteins are characterized by multiple repeats of tetratricopeptide repeat helix-turn-helix motifs mediating a variety of protein-protein interactions, which result in a multitude of effects on cellular and viral functions, such as translation initiation, virus replication, double-stranded RNA signaling, cell migration, and proliferation.