| 摘要 |
<p>Regulatory elements responsible for tissue-specific transcriptional regulation of the human β3-adrenergic receptor (β3-AR) are identified. A region localized between -6.50 and -6.30 kb of the proximal promoter contained three sequences that act synergistically to achieve full transcriptional activity. One segment, termed segment A, contains an Sp1 binding site. Another of the sequences, termed segment B, is a binding site for a trans-acting factor present in cells that constitutively express β3-AR. In a specific embodiment, the trans-acting factor is expressed in neuroblastoma (SK-N-MC) and brown adipose tissue cells, but little or not at all in CV-1, HeLa, or white adipose tissue cells. The third segment, C, is an S1 nuclease-sensitive site having CCTT repeats. Recombinant vectors under control of this transcriptional regulation region, particularly containign the B and C segments, provide a substrate for high throughput assays, such as reporter gene assays, to identify compounds that can increase the level of expression of β3-AR. The B segment nucleic acids also provide for isolation and cloning of the trans-acting factor. Mechanisms of transcriptional regulation and identification of other adjacent proteins involved in the regulation of the hβ3-AR gene expression are provided.</p> |
