Transcription termination of mouse Nkx-1.1 gene

Abstract

Transcriptional control element in the 3`` flanking region of the mouse Nkx-1.1 gene was identified. A downstream transcriptional regulatory element in the mouse Nkx-1.1 gene was characterized by transferring the Nkx-1.1 gene 3‘ fragment(Nkx360) into the shuttle vector pRCX at a site located immediately downstream from the chloramphenicol acetyl transferase gene(CAT) and upstream from the bovine growth hormone polyadenylation region. Analysis of the recombinant plasmid by CAT assay and by nuclease S1 mapping of transcripts indicated the possible involvement of two poly(dG-dT)ㆍpoly(dC-dA) sequences and their flanking sequences in transcription termination. Those sequences was capable of directing termination in an orientation independent manner. Gel mobility shift assay showed specific bindings of several nuclear factors to the element. The element contains two poly(dG-dT)ㆍpoly(dC-dA)(GT repeat) sequences. Sequences surrounding each GT repeat are the same and they form a unit of direct repeat including GT repeat. Some specific DNA structure formed by GT repeats and their flanking sequences, and nuclear DNA-binding proteins might be involved in the termination process.