CLONING OF CHICKEN INTERFERON REGULATORY FACTOR-II (IRF-2) CDNA - EXPRESSION AND MAPPING OF THE IRF-2 GENE

A cDNA clone encoding a member of the avian interferon regulatory fact or (IRF) family homologous to mammalian IRF-2 was isolated from a cDNA library from poly[rI:rC]-induced chicken embryo fibroblasts (CEF), Th e deduced amino acid sequence shows a characteristic DNA binding domai n of 124 amino acids at the amino-terminal end with 96.8% identity to human and 96% to mouse IRF-2 Identities in the C-terminal part are 77. 5% and 77%, respectively. Identity to all other known members of the c hicken IRF (Ch-IRF) family is distinctly lower. In C32 cells, an IRF-2 mRNA of 2.4 kb is constitutively expressed in very low amounts but is inducible by Ch-IFN in the absence or presence of cycloheximide. The Ch-IRF-2 gene is a single copy gene and was mapped by fluorescence in situ hybridization to the long arm of chromosome 4.