Analysis of proteins binding to the proximal promoter region of two rat serine protease inhibitor genes.

The three serine protease inhibitor (SPI) rat genes expressed preferentially in liver share considerable structural features and, nonetheless, are transcriptionally regulated in completely different manners, more particularly after hypophysectomy or upon acute inflammation. DNase I footprinting and gel mobility shift analyses of the SPI 2.1 and 2.3 proximal promoter regions reveal the presence of three common protein binding sites (1 to 3, 3' to 5') located immediately upstream from the transcription start site. C/EBP, the liver-enriched factor, specifically interacts with site 1 whereas its related proteins (e.g.; DBP, LAP/NFIL6) most likely recognize sites 2 and 3. Another ubiquitous unidentified factor also binds to site 2. A liver-specific protein dependent on growth hormone, whose binding is competed out by an oligonucleotide reproducing an HNF3 motif, interacts exclusively with site 3. The 42 bp sequence which is found only within the SPI 2.3 promoter interacts with two ubiquitous factors, one of which is related to NF kappa B. Acute inflammation does not significantly affect the protein binding patterns observed with the SPI 2.1 or 2.3 proximal promoter sequences. Our results show an apparent discrepancy between the large magnitude of in vivo changes in SPI gene transcription mediated by hormones and the small alterations detected in vitro, in the DNA-protein interactions on the promoters

Primary structure and assignment to chromosome 6 of three related rat genes encoding liver serine protease inhibitors.

Three closely related SPI genes which encode highly homologous proteins of the serine protease inhibitor family secreted by rat liver (SPI-1, SPI-2 and SPI-3), were isolated from genomic libraries and sequenced, totally (SPI-2) or partially (SPI-1 and SPI-3). These genes all map on rat chromosome 6. Each of them spans about 10 kb and contains five exons separated by four introns, located at equivalent positions. S1 mapping analysis indicated that initiation of transcription occurs at the same position (tsp) in each of the three genes. In vitro transcription experiments demonstrated the presence of promoter elements upstream from the putative tsp. Detailed analysis of 5'-flanking sequences in the three SPI revealed major differences. A high degree of identity (70%) was found within a 350-bp region preceding the 'cap' site, with the exception of a 42-bp spacer, which was only found in SPI-3. Upstream from that point, SPI-1 and SPI-2 sequences remain largely homologous over at least 1 kb but completely diverge from the corresponding sequence in SPI-3. This may, at least partly, account for the differential regulation of the three SPI observed during acute inflammation and upon hypophysectomy.Journal ArticleResearch Support, Non-U.S. Gov'tSCOPUS: ar.jinfo:eu-repo/semantics/publishe