Two forms of avian(chicken) TATA-binding protein mRNA generated by alternative polyadenylation.

We have isolated and sequenced the cDNA encoding avian(chicken) TATA-binding protein (cTBP). The cTBP protein shows a significant homology to those of the other species, and especially its C-terminal region (180 amino acid residues) is identical to those of the vertebrates. By Northern blot analysis, we found that two transcripts with about 2.1 kb (cTBP0) and 2.7 kb (cTBP1) were expressed in various chicken tissues, though only one type of the TBP transcript was reported in vertebrates. A primer extension study demonstrated a single transcription start site. The analysis of the genomic structure of cTBP with the sequences of the two types of cTBP cDNAs(cTBP0 and cTBP1) revealed that the alternative polyadenylation generates two transcripts with different 3'untranslated regions (3'UTRs), indicating a putative role of the different 3'UTRs on the stability of cTBP mRNAs.