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生物转录的延伸和终止。我们最近的研究表明，特定的RNA序列元件可以以一种不导致新生转录物聚腺苷化的方式指导RNA聚合酶II的终止。在酿酒酵母中，这种机制被用于产生非聚腺苷化的小核和小核核rna （snrna和snoRNAs）上的3-末端。此外，我们已经证明了几种mrna是由类似的机制调节的。这一调控途径需要两种rna结合蛋白Nrd1和Nab3的作用，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解旋酶和pol II CTD和CTD激酶。所提出的研究的近期目标是准确了解Nrd1和Nab3如何起作用导致转录终止，而长期目标是了解CTD和SCAFs在通过RNA聚合酶II调节转录中的作用。在本提案中，我们的具体目标是：(1)定义通过Nrd1 -Nab3途径调节转录伸长的顺式元件；(2)进一步剖析Nrd1通路各组分之间的遗传相互作用；(3)建立nrd1p - nab3p依赖的体外终止实验；(4)表征哺乳动物nrd1样蛋白（SCAFs），确定它们是否在调控转录终止中发挥类似作用。新生pol II转录物中序列触发非聚腺苷化转录物终止的能力是一种新的调控机制。这一途径与调节HIV LTR转录本伸长的机制类似。与HIV调控类似，Nrd1-Nab3机制需要pol II CTD和一个CTD激酶。进一步了解这一途径对于理解真核生物基因是如何调控的以及这些途径是如何因治疗原因而被调节的将是重要的

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