Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Critical Care giúp cho các bạn có thêm kiến thức về ngành y học đề tài:RNA polymerase II stalling: loading at the start prepares genes for a sprint. | Review RNA polymerase II stalling loading at the start prepares genes for a sprint Jia Qian Wu and Michael Snyder Addresses Molecular Cellular and Developmental Biology Department and fMolecular Biophysics and Biochemistry Department Yale University PO Box 208103 New Haven CT 06511 USA. Correspondence Michael Snyder. Email Published 2 May 2008 Genome Biology 2008 9 220 doi gb-2008-9-5-220 The electronic version of this article is the complete one and can be found online at http 2008 9 5 220 2008 BioMed Central Ltd Abstract Stalling of RNA polymerase II near the promoter has recently been found to be much more common than previously thought. Genome-wide surveys of the phenomenon suggest that it is likely to be a rate-limiting control on gene activation that poises developmental and stimulus-responsive genes for prompt expression when inducing signals are received. The recruitment of RNA polymerase II Pol II to the promoter has been generally believed to be the rate-limiting step in gene activation 1 . However a series of discoveries made since the mid-1980s combined with recent genomewide studies suggest that many developmental and inducible Drosophila and mammalian genes prior to their expression contain Pol II bound predominantly in their promoter proximal regions in a stalled state 1-8 . Activation of the stalled polymerase is thought to be responsible for the expression of these genes 1 . Distinct sets of accessory factors are associated with Pol II stalling and its escape from stalling acting either by direct interaction with Pol II or by manipulating the chromatin environment - for example by affecting histone modifications by histone methyltransferases HMTs or histone acetyltransferases HATs 1 . Proteins associated with Pol II stalling include the DRB sensitivity-inducing factor DSIF and the negative elongation factor NELF 9 10 whereas proteins such as the positive transcription-elongation factor-b P-TEFb .
