scholarly journals The RSC complex remodels nucleosomes in transcribed coding sequences and promotes transcription in Saccharomyces cerevisiae

Genetics ◽  
2021 ◽  
Author(s):  
Emily Biernat ◽  
Jeena Kinney ◽  
Kyle Dunlap ◽  
Christian Rizza ◽  
Chhabi K Govind

Abstract RSC (Remodels the Structure of Chromatin) is a conserved ATP-dependent chromatin remodeling complex that regulates many biological processes, including transcription by RNA polymerase II (Pol II). We report that RSC contributes in generating accessible nucleosomes in transcribed coding sequences (CDSs). RSC MNase ChIP-seq data revealed that RSC-bound nucleosome fragments were very heterogenous (∼80 bp to 180 bp) compared to a sharper profile displayed by the MNase inputs (140 bp to 160 bp), supporting the idea that RSC promotes accessibility of nucleosomal DNA. Notably, RSC binding to + 1 nucleosomes and CDSs, but not with -1 nucleosomes, strongly correlated with Pol II occupancies, suggesting that RSC enrichment s CDSs is linked to transcription. We also observed that Pol II associates with nucleosomes throughout transcribed CDSs, and similar to RSC, Pol II-protected fragments were highly heterogenous, consistent with the idea that Pol II interacts with remodeled nucleosomes in CDSs. This idea is supported by the observation that the genes harboring high-levels of Pol II in their CDSs were the most strongly affected by ablating RSC function. Additionally, rapid nuclear depletion of Sth1 decreases nucleosome accessibility and results in accumulation of Pol II in highly transcribed CDSs. This is consistent with a slower clearance of elongating Pol II in cells with reduced RSC function, and is distinct from the effect of RSC depletion on PIC assembly. Altogether, our data provide evidence in support of the role of RSC in promoting Pol II elongation, in addition to its role in regulating transcription initiation.

Author(s):  
Emily Biernat ◽  
Jeena Kinney ◽  
Kyle Dunlap ◽  
Christian Rizza ◽  
Chhabi K Govind

RSC (Remodels the Structure of Chromatin) is a conserved ATP-dependent chromatin remodeling complex that regulates many biological processes, including transcription by RNA polymerase II (Pol II). We report that not only RSC binds to nucleosomes in coding sequences (CDSs) but also remodels them to promote transcription. RSC MNase ChIP-seq data revealed that RSC-protected fragments were very heterogenous (~80 bp to 180 bp) compared to the sharper profile displayed by the MNase inputs (140 bp to 160 bp), supporting the idea that RSC activity promotes accessibility of nucleosomal DNA. Importantly, RSC binding to +1 nucleosomes and CDSs, but not with -1 nucleosomes, strongly correlated with Pol II occupancies suggesting that the RSC enrichment in CDSs is important for efficient transcription. This is further supported by a similar heterogenous distribution of Pol II-protected fragments. As such, the genes harboring high-levels of RSC in their CDSs were the most strongly affected by ablating RSC function. Altogether, this study provides a mechanism by which RSC-mediated remodeling aids in RNA Pol II traversal though coding sequence nucleosomes in vivo.


2012 ◽  
Vol 2012 ◽  
pp. 1-19 ◽  
Author(s):  
David W. Zhang ◽  
Juan B. Rodríguez-Molina ◽  
Joshua R. Tietjen ◽  
Corey M. Nemec ◽  
Aseem Z. Ansari

The C-terminal domain (CTD) of RNA polymerase II (Pol II) consists of conserved heptapeptide repeats that function as a binding platform for different protein complexes involved in transcription, RNA processing, export, and chromatin remodeling. The CTD repeats are subject to sequential waves of posttranslational modifications during specific stages of the transcription cycle. These patterned modifications have led to the postulation of the “CTD code” hypothesis, where stage-specific patterns define a spatiotemporal code that is recognized by the appropriate interacting partners. Here, we highlight the role of CTD modifications in directing transcription initiation, elongation, and termination. We examine the major readers, writers, and erasers of the CTD code and examine the relevance of describing patterns of posttranslational modifications as a “code.” Finally, we discuss major questions regarding the function of the newly discovered CTD modifications and the fundamental insights into transcription regulation that will necessarily emerge upon addressing those challenges.


2020 ◽  
Vol 6 (50) ◽  
pp. eaaz7420
Author(s):  
Ryo Onishi ◽  
Kaoru Sato ◽  
Kensaku Murano ◽  
Lumi Negishi ◽  
Haruhiko Siomi ◽  
...  

Drosophila Piwi associates with PIWI-interacting RNAs (piRNAs) and represses transposons transcriptionally through heterochromatinization; however, this process is poorly understood. Here, we identify Brahma (Brm), the core adenosine triphosphatase of the SWI/SNF chromatin remodeling complex, as a new Piwi interactor, and show Brm involvement in activating transcription of Piwi-targeted transposons before silencing. Bioinformatic analyses indicated that Piwi, once bound to target RNAs, reduced the occupancies of SWI/SNF and RNA polymerase II (Pol II) on target loci, abrogating transcription. Artificial piRNA-driven targeting of Piwi to RNA transcripts enhanced repression of Brm-dependent reporters compared with Brm-independent reporters. This was dependent on Piwi cofactors, Gtsf1/Asterix (Gtsf1), Panoramix/Silencio (Panx), and Maelstrom (Mael), but not Eggless/dSetdb (Egg)–mediated H3K9me3 deposition. The λN-box B–mediated tethering of Mael to reporters repressed Brm-dependent genes in the absence of Piwi, Panx, and Gtsf1. We propose that Piwi, via Mael, can rapidly suppress transcription of Brm-dependent genes to facilitate heterochromatin formation.


2021 ◽  
Author(s):  
Xizi Chen ◽  
Yilun Qi ◽  
Xinxin Wang ◽  
Zhenning Wang ◽  
Li Wang ◽  
...  

RNA polymerase II (Pol II)-mediated transcription in metazoan requires precise regulation. RNA polymerase II-associated protein 2 (RPAP2) was previously identified to transport Pol II from cytoplasm to nucleus and dephosphorylates Pol II C-terminal domain (CTD). We found that RPAP2 binds hypo/hyper-phosphorylated Pol II with undetectable phosphatase activity. Structure of RPAP2-Pol II shows mutually exclusive assembly of RPAP2-Pol II and pre-initiation complex (PIC) due to three steric clashes. RPAP2 prevents/disrupts Pol II-TFIIF interaction and impairs in vitro transcription initiation, suggesting a function in prohibiting PIC assembly. Loss of RPAP2 in cells leads to global accumulation of TFIIF and Pol II at promoters, indicating critical role of RPAP2 in inhibiting PIC assembly independent of its putative phosphatase activity. Our study indicates that RPAP2 functions as a gatekeeper to prohibit PIC assembly and transcription initiation and suggests a novel transcription checkpoint.


2020 ◽  
Author(s):  
A.I. Garrido-Godino ◽  
A. Cuevas-Bermúdez ◽  
F. Gutiérrez-Santiago ◽  
M.C. Mota-Trujillo ◽  
F. Navarro

ABSTRACTRtr1 is an RNA pol II CTD-phosphatase that influences gene expression by acting during the transition from transcription initiation to elongation, and during transcription termination. Rtr1 has been proposed as an RNA pol II import factor in RNA pol II biogenesis, and participating in mRNA decay by autoregulating the turnover of its own mRNA. In addition, the interaction of Rtr1 with RNA pol II depends on the phosphorylation state of CTD, which also influences Rpb4/7 dissociation during transcription. In this work, we demonstrate that Rtr1 acts in RNA pol II assembly, likely in a final cytoplasmic RNA pol II biogenesis step, and mediates the Rpb4 association with the rest of the enzyme, However, we do not rule out discard a role in the Rpb4 association with RNA pol II in the nucleus. This role of Rtr1 interplays RNA pol II biogenesis and mRNA decay regulation. In fact, RTR1 deletion alters RNA pol II assembly and leads to the chromatin association of RNA pol II lacking Rpb4, in addition to whole RNA pol II, decreasing mRNA-Rpb4 imprinting and, consequently, increasing mRNA stability. Notably, the RPB5 overexpression that overcomes RNA pol II assembly and the defect in Rpb4 binding to chromatin-associated RNA pol II partially suppresses the mRNA stability defect of rtr1Δ cells. Our data also indicate that Rtr1 mediates mRNA decay regulation more broadly than previously proposed in cooperation with Rpb4 and Dhh1. Interestingly, these data include new layers in the crosstalk between mRNA synthesis and decay.


2020 ◽  
Author(s):  
Vu Q. Nguyen ◽  
Anand Ranjan ◽  
Sheng Liu ◽  
Xiaona Tang ◽  
Yick Hin Ling ◽  
...  

SUMMARYTranscription initiation by RNA polymerase II (Pol II) requires preinitiation complex (PIC) assembly at gene promoters. In the dynamic nucleus where thousands of promoters are broadly distributed in chromatin, it is unclear how ten individual components converge on any target to establish the PIC. Here, we use live-cell, single-molecule tracking in S. cerevisiae to document subdiffusive, constrained exploration of the nucleoplasm by PIC components and Mediator’s key functions in guiding this process. On chromatin, TBP, Mediator, and Pol II instruct assembly of a short-lived PIC, which occurs infrequently but efficiently at an average promoter where initiation-coupled disassembly may occur within a few seconds. Moreover, PIC exclusion by nucleosome encroachment underscores regulated promoter accessibility by chromatin remodeling. Thus, coordinated nuclear exploration and recruitment to accessible targets underlies dynamic PIC establishment in yeast. Collectively, our study provides a global spatio-temporal model for transcription initiation in live cells.


2006 ◽  
Vol 235 (10) ◽  
pp. 2722-2735 ◽  
Author(s):  
Binnur Eroglu ◽  
Guanghu Wang ◽  
Naxin Tu ◽  
Xutong Sun ◽  
Nahid F. Mivechi

2021 ◽  
Vol 90 (1) ◽  
pp. 193-219
Author(s):  
Emmanuel Compe ◽  
Jean-Marc Egly

In eukaryotes, transcription of protein-coding genes requires the assembly at core promoters of a large preinitiation machinery containing RNA polymerase II (RNAPII) and general transcription factors (GTFs). Transcription is potentiated by regulatory elements called enhancers, which are recognized by specific DNA-binding transcription factors that recruit cofactors and convey, following chromatin remodeling, the activating cues to the preinitiation complex. This review summarizes nearly five decades of work on transcription initiation by describing the sequential recruitment of diverse molecular players including the GTFs, the Mediator complex, and DNA repair factors that support RNAPII to enable RNA synthesis. The elucidation of the transcription initiation mechanism has greatly benefited from the study of altered transcription components associated with human diseases that could be considered transcription syndromes.


2004 ◽  
Vol 24 (18) ◽  
pp. 8227-8235 ◽  
Author(s):  
Vardit Dror ◽  
Fred Winston

ABSTRACT The Swi/Snf chromatin remodeling complex has been previously demonstrated to be required for transcriptional activation and repression of a subset of genes in Saccharomyces cerevisiae. In this work we demonstrate that Swi/Snf is also required for repression of RNA polymerase II-dependent transcription in the ribosomal DNA (rDNA) locus (rDNA silencing). This repression appears to be independent of both Sir2 and Set1, two factors known to be required for rDNA silencing. In contrast to many other rDNA silencing mutants that have elevated levels of rDNA recombination, snf2Δ mutants have a significantly decreased level of rDNA recombination. Additional studies have demonstrated that Swi/Snf is also required for silencing of genes near telomeres while having no detectable effect on silencing of HML or HMR.


2020 ◽  
Author(s):  
Motoyuki Tsuda ◽  
Akihisa Fukuda ◽  
Munenori Kawai ◽  
Osamu Araki ◽  
Hiroshi Seno

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