Wolf J B, David V A, Deutch A H
BioMolecular Research Department, W.R. Grace and Co-Conn., Washington Research Center, Columbia, MD 21044.
Nucleic Acids Res. 1990 Aug 25;18(16):4905-12.
The 5'-flanking region of the bovine prolactin gene was cloned and sequenced. The expression of chimeric gene constructs containing 5'-flanking DNA fragments from the prolactin gene joined to a reporter gene encoding human growth hormone (hGH) was examined using transiently transfected rat pituitary cells. Prolactin nucleotide sequences located at position -1213 to -925 enhance the basal level of expression of growth hormone by 5-fold and function in a position- and orientation-independent fashion. In addition to increasing the basal level of growth hormone expression, this enhancer element also responds to induction by epidermal growth factor. The nucleotide sequence of the bovine prolactin gene enhancer element is highly similar to an enhancer element located approximately -1.5 kb from the rat prolactin transcription initiation site. Deletion analysis of the enhancer region shows that sequences -1124 to -985 are necessary and sufficient for enhancer activity.
克隆并测序了牛催乳素基因的5'侧翼区域。使用瞬时转染的大鼠垂体细胞,检测了包含来自催乳素基因的5'侧翼DNA片段与编码人生长激素(hGH)的报告基因连接的嵌合基因构建体的表达。位于-1213至-925位置的催乳素核苷酸序列将生长激素的基础表达水平提高了5倍,并且以位置和方向独立的方式发挥作用。除了增加生长激素表达的基础水平外,该增强子元件还对表皮生长因子的诱导作出反应。牛催乳素基因增强子元件的核苷酸序列与距大鼠催乳素转录起始位点约-1.5 kb处的增强子元件高度相似。增强子区域的缺失分析表明,-1124至-985序列对于增强子活性是必需且足够的。