Live-cell imaging of RNA Pol II and elongation factors distinguishes competing mechanisms of transcription regulation.

Autor:	Versluis P; Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA., Graham TGW; Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA., Eng V; Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA., Ebenezer J; Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA; Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY 14853, USA., Darzacq X; Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA., Zipfel WR; Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY 14853, USA., Lis JT; Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA. Electronic address: jtl10@cornell.edu.
Jazyk:	angličtina
Zdroj:	Molecular cell [Mol Cell] 2024 Aug 08; Vol. 84 (15), pp. 2856-2869.e9.
DOI:	10.1016/j.molcel.2024.07.009
Abstrakt:	RNA polymerase II (RNA Pol II)-mediated transcription is a critical, highly regulated process aided by protein complexes at distinct steps. Here, to investigate RNA Pol II and transcription-factor-binding and dissociation dynamics, we generated endogenous photoactivatable-GFP (PA-GFP) and HaloTag knockins using CRISPR-Cas9, allowing us to track a population of molecules at the induced Hsp70 loci in Drosophila melanogaster polytene chromosomes. We found that early in the heat-shock response, little RNA Pol II and DRB sensitivity-inducing factor (DSIF) are reused for iterative rounds of transcription. Surprisingly, although PAF1 and Spt6 are found throughout the gene body by chromatin immunoprecipitation (ChIP) assays, they show markedly different binding behaviors. Additionally, we found that PAF1 and Spt6 are only recruited after positive transcription elongation factor (P-TEFb)-mediated phosphorylation and RNA Pol II promoter-proximal pause escape. Finally, we observed that PAF1 may be expendable for transcription of highly expressed genes where nucleosome density is low. Thus, our live-cell imaging data provide key constraints to mechanistic models of transcription regulation. Competing Interests: Declaration of interests The authors declare no competing interests. (Copyright © 2024 Elsevier Inc. All rights reserved.)
Databáze:	MEDLINE
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