Genomic organization of the gene for mouse PIASgamma and analysis of its promoter

Signal transducer and transcriptional activator (STAT) proteins are latent cytoplasmic transcription factors that are activated in response to stimulation by various cytokines. Protein Inhibitors of Activated STAT (PIAS) proteins comprise a family of five mammalian proteins which have been identified as potentially important downregulators of the STAT signaling pathway. We have previously reported the identification and expression of the mouse homologue of PIAS family member PIASgamma. Here we report the isolation by genomic 5'-RACE PCR and in vitro analysis of the mouse PIASgamma promoter region and the genomic structure and organization of the mouse and human PIASgamma genes. Human PIASgamma spans approximately 23 kb on chromosome 19 and is organized into ten exons. The size of mouse PIASgamma is 16 kb and also organized into ten exons with the intron/exon structure of the two genes conserved in both species. As a result, considerable conservatism of the mouse and human intron sequences was observed. Analysis of a 1.4 kb genomic fragment containing the mouse PIASgamma promoter allowed us to map the transcription 'Start' site of the gene, determine the sequences essential for the activity of this promoter and to define a minimal promoter region.