TERMINATION OF TRANSCRIPTION BY RNA POLYMERASE I

转录终止是一个经常使用的控制点 在原核生物中调节基因表达。 然而，在多大程度上 这在真核生物中是否正确尚不清楚。 目前，终止 在真核生物中最好理解的系统是RNA聚合酶I， 这主要归功于我们实验室对非洲爪蟾的研究 以及在Ingrid Grummt实验室对老鼠的研究。 的位点 终止是已知的，这些位点的各种突变体是可用的， 用于终止的良好测定系统已经在体内和体外被开发， 体外 参与终止的蛋白质的分离正在进行中 我们已经开始为这个过程提出可测试的模型。 在本申请中，我们建议继续研究RNA聚合酶I 终止于Xenopus。 参与终止的蛋白质将 使用体外终止系统鉴定和纯化。 的基因 因为这些蛋白质将被克隆和鉴定。 的核心 然后，建议是确定这些分子的分子机制， 组分通过RNA聚合酶I终止转录。

Termination of transcription is a control point that is frequently utilized in prokaryotes to regulate gene expression. However, the extent to which this is true in eukaryotes is not yet clear. At present, the termination system which is best understood in eukaryotes is that of RNA polymerase I, due largely to studies on the frog, Xenopus laevis, in our own laboratory and studies on the mouse in the laboratory of Ingrid Grummt. The sites of termination are known, various mutants of these sites are available, and good assay systems for termination have been developed both in vivo and vitro. Fractionation of the proteins involved in termination is underway and we have begun to propose testable models for the process. In this application we propose to continue studies of RNA polymerase I termination in Xenopus. The proteins involved in termination will be identified and purified using and in vitro termination system. The genes for these proteins will be cloned and characterized. The heart of the proposal then is to determine the molecular mechanism by which these components effect termination of transcription by RNA polymerase I.