THE GENOMIC STRUCTURE OF THE CHICKEN ICSBP GENE AND ITS TRANSCRIPTIONAL REGULATION BY CHICKEN INTERFERON

The chicken interferon consensus sequence binding protein (ChICSBP) ge ne spans over 9 kb of DNA and consists, as its murine homolog, of nine exons. The first untranslated exon was identified by 5'-RACE technolo gy. The second exon contains the translation initiation codon. Canonic al consensus splice sites are found on every exon/intron junction. The introns are generally smaller than their mammalian counterparts. The ChICSBP and ChIRF-1 genes have been mapped by fluorescence in situ hyb ridization to different microchromosomes. The transcription start site has been mapped by primer extension. Inspection of the DNA sequence o f a genomic clone containing the first exon and the region 1700-bp ups tream revealed several potential cis-regulatory elements of transcript ion. The ChICSBP mRNA is induced by recombinant ChIFN type I and ChIFN -gamma. A palindromic IFN regulatory element (pIRE) with high sequence homology to gamma activation site (GAS) sequences was functionally re quired in transient transfection assays for the induction of transcrip tion by ChIFN-gamma. (C) 1998 Elsevier Science B.V.