TATA-less Mouse Vitronectin Gene Promoter: Characterization of the Transcriptional Regulatory Elements and a Nuclear Protein Binding Site on the Promoter.

Abstract

Key words: vitronectin/promoter/TATA box/initiator/transcription/nuclear protein ABSTRACT. Vitronectin in a cell-adhesion molecule whoseexpression is temporally and spatially regulated in vivo, but whoseregulatory mechanismof transcription is unknown.In this study, we characterized the mousevitronectin gene promoter. Luciferase expression vectors cloned the successive 5'-or 3 -deletions of the 5 -flanking region upstream of the luciferase gene and were transfected into the humanhepatoma cell line HepG2.The assay of luciferase activity in the transfected cells revealed that a 38 base pair (bp)-element (positions +3 to +40) displays promoter activity. A consensus sequence consisting of a TATAbox and initiator is shown around the transcription initiation site of the mouse vetronectin gene, but the GCbox is not shown. Site-directed or deleted mutagenesis against a consensus sequence of TATA box and initiator could not abolish the promoter activity. These results induce that the putative TATAbox and initiator are not involved in the promoter activity, and that the vitronectin promoter lacks the TATAbox, initiator and GCbox. To characterize trans-acting factors involved in promoter activity, a DNAfragment (position -74 to +95) was subjected to gel shift assay using nuclear proteins extracted from HepG2 cells. One shifted band was detected by the gel shift assay, suggesting that a nuclear protein binds to the promoter region. Results of the DNase I foot printing assay and gel shift assay demonstrate that the nuclear proteins can bind to the 38 bp-element, which has promoter activity. The nuclear protein is a putative trans-acting factor involved in transcription initiation.

Cloning and analysis of rat osteoclast inhibitory lectin gene promoter

“…These results suggest that additional core promoter motifs may play a key role in specific transcription initiation at a significant number of human and yeast promoters that lack both TATA and Inr elements. There are strong evidences demonstrating that the transcription of TATA‐ and Inr‐less promoters can be activated either by transcription factor Sp1 in most cases [Hasan and MacDonald, 2002; Kim et al, 2002; Andersen et al, 2004; Le Mée et al, 2005; Zeng et al, 2005; Dong et al, 2008], or in fewer cases, by several other transcription factors that do not belong to Sp family members [Miyamoto et al, 1998; Kam et al, 2005]. It has long been known that Sp1‐binding sites (i.e., GC‐boxes) are frequently found in TATA‐less promoters within CpG islands and that Sp1 can be located on the sense and antisense strands [Mieda et al, 1996], which can direct transcription initiation from core promoters lacking both TATA and Inr elements [Smale and Kadonaga, 2003].…”

Integrin αvβ3 promotes vitronectin gene expression in human ovarian cancer cells by implicating rel transcription factors

“…The VN gene had been mapped to the centromeric region of the long arm of chromosome 17 (Fink et al, 1992). Both the human and mouse VN promoter were cloned and the regulatory sequences 1.8 kb pair upstream of the translational initiation site determined (Jenne and Stanley, 1987; Seiffert et al, 1993, 1996; Miyamoto et al, 1998). Besides still unresolved issues concerning transcriptional initiation, also transcription factors contributing to VN promoter activation have so far not been characterized in great detail (Seiffert et al, 1993, 1996).…”