Simpson Querrey Center for Epigenetics, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA; Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.
Department of Human Genetics, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
Mol Cell. 2020 Apr 16;78(2):261-274.e5. doi: 10.1016/j.molcel.2020.02.014. Epub 2020 Mar 9.
RNA polymerase II (RNA Pol II) is generally paused at promoter-proximal regions in most metazoans, and based on in vitro studies, this function has been attributed to the negative elongation factor (NELF). Here, we show that upon rapid depletion of NELF, RNA Pol II fails to be released into gene bodies, stopping instead around the +1 nucleosomal dyad-associated region. The transition to the 2nd pause region is independent of positive transcription elongation factor P-TEFb. During the heat shock response, RNA Pol II is rapidly released from pausing at heat shock-induced genes, while most genes are paused and transcriptionally downregulated. Both of these aspects of the heat shock response remain intact upon NELF loss. We find that NELF depletion results in global loss of cap-binding complex from chromatin without global reduction of nascent transcript 5' cap stability. Thus, our studies implicate NELF functioning in early elongation complexes distinct from RNA Pol II pause-release.
RNA 聚合酶 II（RNA Pol II）通常在大多数后生动物的启动子近端区域暂停，基于体外研究，这一功能归因于负延伸因子（NELF）。在这里，我们表明，在 NELF 快速耗尽后，RNA Pol II 无法进入基因体，而是在 +1 核小体二联体相关区域周围停止。向第二个暂停区域的转变不依赖于正转录延伸因子 P-TEFb。在热休克反应期间，RNA Pol II 迅速从热休克诱导基因的暂停中释放出来，而大多数基因则暂停并转录下调。NELF 缺失后，热休克反应的这两个方面仍然完整。我们发现，NELF 耗尽导致帽结合复合物从染色质中丢失，而新生转录物 5' 帽稳定性没有全局降低。因此，我们的研究表明，NELF 在后延伸复合物中的作用不同于 RNA Pol II 的暂停释放。
