Bitter G A, Chang K K, Egan K M
Department of Molecular Genetics, Amgen Inc., Thousand Oaks, CA 91320.
Mol Gen Genet. 1991 Dec;231(1):22-32. doi: 10.1007/BF00293817.
The majority of the activation potential of the Saccharomyces cerevisiae TDH3 gene promoter is contained within nucleotides -676 to -381 (relative to the translation initiation codon). An upstream activation sequence (UAS) in this region has been characterized by in vitro and in vivo assays and demonstrated to be composed of two small, adjacent DNA sequence elements. The essential determinant of this upstream UAS is a general regulatory factor 1 (GRF1) binding site at nucleotides -513 to -501. A synthetic DNA element comprising this sequence, or an analogue in which two of the degenerate nucleotides of the GRF1 site consensus sequence were altered, activated 5' deleted TDH3 and CYC1 promoters. The second DNA element of the UAS is a 7 bp sequence which is conserved in the promoters of several yeast genes encoding glycolytic enzymes and occurs at positions -486 to -480 of the TDH3 promoter. This DNA sequence represents a novel promoter element: it contains no UAS activity itself, yet potentiates the activity of a GRF1 UAS. The potentiation of the GRF1 UAS by this element occurs when placed upstream from the TATA box of either the TDH3 or CYC1 promoters. The characteristics of this element (termed GPE for GRF1 site potentiator element) indicate that it represents a binding site for a different yeast protein which increases the promoter activation mediated by the GRF1 protein. Site-specific deletion and promoter reconstruction experiments suggest that the entire activation potential of the -676 to -381 region of the TDH3 gene promoter may be accounted for by a combination of the GRF1 site and the GPE.
酿酒酵母TDH3基因启动子的大部分激活潜力存在于核苷酸-676至-381(相对于翻译起始密码子)范围内。该区域的一个上游激活序列(UAS)已通过体外和体内试验进行了表征,并证明由两个相邻的小DNA序列元件组成。这个上游UAS的关键决定因素是位于核苷酸-513至-501处的一个通用调节因子1(GRF1)结合位点。一个包含该序列的合成DNA元件,或其中GRF1位点共有序列的两个简并核苷酸被改变的类似物,激活了5'缺失的TDH3和CYC1启动子。UAS的第二个DNA元件是一个7bp序列,在几个编码糖酵解酶的酵母基因的启动子中保守,位于TDH3启动子的-486至-480位置。这个DNA序列代表了一种新型的启动子元件:它本身不具有UAS活性,但能增强GRF1 UAS的活性。当该元件置于TDH3或CYC1启动子的TATA框上游时,它会增强GRF1 UAS的活性。这个元件(称为GRF1位点增强子元件,即GPE)的特征表明它代表了一种不同酵母蛋白的结合位点,该蛋白可增加由GRF1蛋白介导的启动子激活。位点特异性缺失和启动子重建实验表明,TDH3基因启动子-676至-381区域的全部激活潜力可能由GRF1位点和GPE共同作用来解释。