RNA binding RNA polymerase II CTD associated proteins

描述（由申请人提供）：拟议研究的目的是了解一组RNA结合蛋白如何调节真核转录延伸和终止。我们最近的研究表明，特定的RNA序列元件可以直接RNA聚合酶II终止的方式，不会导致新生转录的聚腺苷酸化。在酿酒酵母中，这种机制用于在非聚腺苷酸化的小核和小核仁RNA（snRNA和snoRNA）上产生3-末端。此外，我们已经证明，几种mRNA的调控机制相似。这种调节途径需要两种RNA结合蛋白Nrd 1和Nab 3的功能，并通过识别新生转录物中的特定顺式元件来运作。该途径还需要Seni RNA解旋酶以及pol II CTD和CTD激酶。本研究的近期目标是精确地理解Nrd 1和Nab 3是如何导致转录终止的，而长期目标是理解CTD和SCAFs在RNA聚合酶II调节转录中的作用。在本研究中，我们的具体目标是：（1）定义通过Nrd 1-Nab 3途径调节转录延伸的顺式元件;（2）进一步研究Nrd 1通路各组分间的遗传相互作用;（3）建立Nrd 1 p-Nab 3 p依赖的体外终止实验;（4）哺乳动物Nrd 1样蛋白（SCAFs）的鉴定并确定它们是否在调节转录终止中起类似的作用。非多聚腺苷酸化转录物是一种新的调节机制。该途径类似于调节HIV LTR转录物延伸的机制。与HIV调节类似，Nrd 1-Nab 3机制需要pol II CTD和CTD激酶。进一步了解这一途径对于理解真核基因是如何被调控的以及这些途径是如何被调节以达到治疗的目的是很重要的

DESCRIPTION (provided by applicant): The objective of the proposed studies is to understand how a set of RNA-binding proteins regulate eucaryotic transcription elongation and termination. Our recent studies indicate that specific RNA sequence elements can direct RNA polymerase II termination in a manner that does not lead to polyadenylation of the nascent transcript. In Saccharomyces cerevisiae this mechanism is used to produce 3-ends on non-polyadenylated small nuclear and small nucleolar RNAs (snRNAs and snoRNAs). In addition, we have shown that several mRNAs are regulated by a similar mechanism. This regulatory pathway requires the function of two RNA-binding proteins, Nrd1 and Nab3, and operates through recognition of specific cis-elements in the nascent transcript. This pathway also requires the Seni RNA helicase and both the pol II CTD and a CTD kinase. The immediate objective of the proposed studies is to understand precisely how Nrd1 and Nab3 function to cause transcription termination while the longer term objective is to understand the role of the CTD and SCAFs in regulating transcription by RNA polymerase II.In this proposal our specific aims are to: (1) Define cis-elements that regulate transcription elongation through the Nrd1 -Nab3 pathway; (2) Further dissect the genetic interactions among components of the Nrd1 pathway; (3) Develop a Nrd1p-Nab3p-dependent in vitro termination assay; and (4) Characterize mammalian Nrd1-Iike proteins (SCAFs) and determine whether they play a similar role in regulating transcription termination.The ability of sequences in the nascent pol II transcript to trigger termination of non-polyadenylated transcripts is a novel regulatory mechanism. This pathway is similar to the mechanism that regulates elongation of transcripts from the HIV LTR. Similar to HIV regulation, the Nrd1-Nab3 mechanism requires the pol II CTD and a CTD kinase. Further understanding of this pathway will be important in understanding how eucaryotic genes are regulated and how these pathways may be modulated for therapeutic reasons