O'Shea-Greenfield A, Smale S T
Howard Hughes Medical Institute, UCLA School of Medicine 90024.
J Biol Chem. 1992 Jan 15;267(2):1391-402.
Transcriptional initiator elements and TATA elements are functionally similar, in that both can act in concert with a Sp1-dependent activator element to direct high levels of accurately initiated transcription. In this study, we have used in vitro transcription experiments to elucidate the relative activities of TATA and initiator. By varying the locations of TATA and initiator elements within a simple promoter, we compared their abilities to localize transcription start sites and to mediate transcriptional activation by Sp1. In addition, we addressed the contributions of initiator and TATA towards determining the direction of transcription from a promoter. Finally, we addressed the prevalence of initiator elements by analyzing the start site regions of several genes. We found that many of these regions possess initiator activity, although an initiator consensus sequence could not be defined. Taken together, the data presented suggest that an initiator is a common element that can influence the direction of transcription as well as the location of a transcription start site. However, in general, an initiator was incapable of altering these activities of a TATA box within a promoter containing both core elements.
转录起始元件和TATA元件在功能上相似，因为它们都能与Sp1依赖的激活元件协同作用，以指导高水平的精确起始转录。在本研究中，我们利用体外转录实验来阐明TATA和起始元件的相对活性。通过改变简单启动子内TATA和起始元件的位置，我们比较了它们定位转录起始位点以及介导Sp1转录激活的能力。此外，我们探讨了起始元件和TATA对确定启动子转录方向的贡献。最后，我们通过分析几个基因的起始位点区域来研究起始元件的普遍性。我们发现，尽管无法定义起始元件的共有序列，但这些区域中的许多都具有起始活性。综上所述，所呈现的数据表明，起始元件是一种常见元件，它可以影响转录方向以及转录起始位点的位置。然而，一般来说，起始元件无法改变同时包含这两种核心元件的启动子内TATA框的这些活性。
