scholarly journals Distinct Mechanisms for Repression of RNA Polymerase III Transcription by the Retinoblastoma Tumor Suppressor Protein

2004 ◽  
Vol 24 (13) ◽  
pp. 5989-5999 ◽  
Author(s):  
Heather A. Hirsch ◽  
Gauri W. Jawdekar ◽  
Kang-Ae Lee ◽  
Liping Gu ◽  
R. William Henry
Keyword(s):  
Rna Polymerase ◽  
Gene Transcription ◽  
Transcriptional Repression ◽  
Rna Polymerase Iii ◽  
Control Cell ◽  
U6 Snrna ◽  
Retinoblastoma Tumor Suppressor ◽  
Polymerase Iii ◽  
U6 Promoter ◽  
Retinoblastoma Tumor

ABSTRACT The retinoblastoma (RB) protein represses global RNA polymerase III transcription of genes that encode nontranslated RNAs, potentially to control cell growth. However, RNA polymerase III-transcribed genes exhibit diverse promoter structures and factor requirements for transcription, and a universal mechanism explaining global repression is uncertain. We show that RB represses different classes of RNA polymerase III-transcribed genes via distinct mechanisms. Repression of human U6 snRNA (class 3) gene transcription occurs through stable promoter occupancy by RB, whereas repression of adenovirus VAI (class 2) gene transcription occurs in the absence of detectable RB-promoter association. Endogenous RB binds to a human U6 snRNA gene in both normal and cancer cells that maintain functional RB but not in HeLa cells whose RB function is disrupted by the papillomavirus E7 protein. Both U6 promoter association and transcriptional repression require the A/B pocket domain and C region of RB. These regions of RB contribute to U6 promoter targeting through numerous interactions with components of the U6 general transcription machinery, including SNAPC and TFIIIB. Importantly, RB also concurrently occupies a U6 promoter with RNA polymerase III during repression. These observations suggest a novel mechanism for RB function wherein RB can repress U6 transcription at critical steps subsequent to RNA polymerase III recruitment.

scholarly journals The Retinoblastoma Tumor Suppressor Protein Targets Distinct General Transcription Factors To Regulate RNA Polymerase III Gene Expression

2000 ◽  
Vol 20 (24) ◽  
pp. 9182-9191 ◽  
Author(s):  
Heather A. Hirsch ◽  
Liping Gu ◽  
R. William Henry
Keyword(s):  
Transcription Factors ◽  
Rna Polymerase ◽  
Rna Polymerase Iii ◽  
U6 Snrna ◽  
General Transcription Factors ◽  
Retinoblastoma Tumor Suppressor ◽  
Polymerase Iii ◽  
Retinoblastoma Tumor

ABSTRACT The retinoblastoma protein (RB) represses RNA polymerase III transcription effectively both in vivo and in vitro. Here we demonstrate that the general transcription factors snRNA-activating protein complex (SNAPc) and TATA binding protein (TBP) are important for RB repression of human U6 snRNA gene transcription by RNA polymerase III. RB is associated with SNAPc as detected by both coimmunoprecipitation of endogenous RB with SNAPc and cofractionation of RB and SNAPc during chromatographic purification. RB also interacts with two SNAPc subunits, SNAP43 and SNAP50. TBP or a combination of TBP and SNAPcrestores efficient U6 transcription from RB-treated extracts, indicating that TBP is also involved in RB regulation. In contrast, the TBP-containing complex TFIIIB restores adenovirus VAI but not human U6 transcription in RB-treated extracts, suggesting that TFIIIB is important for RB regulation of tRNA-like genes. These results suggest that different classes of RNA polymerase III-transcribed genes have distinct general transcription factor requirements for repression by RB.

scholarly journals Robust repression of tRNA gene transcription during stress requires protein arginine methylation

2019 ◽  
Vol 2 (3) ◽  
pp. e201800261 ◽  
Author(s):  
Richoo B Davis ◽  
Neah Likhite ◽  
Christopher A Jackson ◽  
Tao Liu ◽  
Michael C Yu
Keyword(s):  
Rna Polymerase ◽  
Gene Transcription ◽  
Protein Function ◽  
Transcriptional Repression ◽  
Trna Gene ◽  
Rna Polymerase Iii ◽  
Arginine Methylation ◽  
Major Protein ◽  
Polymerase Iii ◽  
Protein Arginine Methylation

Protein arginine methylation is an important means by which protein function can be regulated. In the budding yeast, this modification is catalyzed by the major protein arginine methyltransferase Hmt1. Here, we provide evidence that the Hmt1-mediated methylation of Rpc31, a subunit of RNA polymerase III, plays context-dependent roles in tRNA gene transcription: under conditions optimal for growth, it positively regulates tRNA gene transcription, and in the setting of stress, it promotes robust transcriptional repression. In the context of stress, methylation of Rpc31 allows for its optimal interaction with RNA polymerase III global repressor Maf1. Interestingly, mammalian Hmt1 homologue is able to methylate one of Rpc31’s human homologue, RPC32β, but not its paralogue, RPC32α. Our data led us to propose an efficient model whereby protein arginine methylation facilitates metabolic economy and coordinates protein-synthetic capacity.

A common octamer motif binding protein is involved in the transcription of U6 snRNA by RNA polymerase III and U2 snRNA by RNA polymerase II

Cell ◽  
1987 ◽  
Vol 51 (1) ◽  
pp. 71-79 ◽  
Author(s):  
Philippe Carbon ◽  
Sylvie Murgo ◽  
Jean-Pierre Ebel ◽  
Alain Krol ◽  
Graham Tebb ◽  
...  
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Binding Protein ◽  
Rna Polymerase Iii ◽  
U2 Snrna ◽  
U6 Snrna ◽  
Polymerase Iii ◽  
Octamer Motif

Characterization of the U3 and U6 snRNA genes from wheat: U3 snRNA genes in monocot plants are transcribed by RNa polymerase III

1992 ◽  
Vol 19 (6) ◽  
pp. 973-983 ◽  
Author(s):  
Christopher Marshallsay ◽  
Sheila Connelly ◽  
Witold Filipowicz
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Iii ◽  
U6 Snrna ◽  
Polymerase Iii

Relative Affinities of Nucleotide Substrates for the Yeast tRNA Gene Transcription Complex

1992 ◽  
Vol 47 (3-4) ◽  
pp. 320-322 ◽  
Author(s):  
Przemyslaw Szafranski ◽  
W. Jerzy Smagowicz
Keyword(s):  
Rna Polymerase ◽  
Gene Transcription ◽  
Trna Gene ◽  
Rna Polymerase Iii ◽  
Rna Polymerases ◽  
Yeast Trna ◽  
Polymerase Iii ◽  
Michaelis Constants ◽  
Auxiliary Protein

Abstract Apparent Michaelis constants for nucleotides in transcription of yeast tRN Agene by hom ologous RNA polymerase III with auxiliary protein factors, were found to be remarkably higher in initiation than in elongation of RNA chain. This supports presumptions regarding topological similarities between catalytic centers of bacterial and eukaryotic RNA polymerases.

scholarly journals Cytoskeletal Filamin A Differentially Modulates RNA Polymerase III Gene Transcription in Transformed Cell Lines

2016 ◽  
Vol 291 (48) ◽  
pp. 25239-25246 ◽  
Author(s):  
Juan Wang ◽  
Shasha Zhao ◽  
Yun Wei ◽  
Ying Zhou ◽  
Paul Shore ◽  
...  
Keyword(s):  
Rna Polymerase ◽  
Cell Lines ◽  
Gene Transcription ◽  
Rna Polymerase Iii ◽  
Filamin A ◽  
Transformed Cell ◽  
Polymerase Iii ◽  
Transformed Cell Lines

scholarly journals Polymerase III transcription factor B activity is reduced in extracts of growth-restricted cells.

1988 ◽  
Vol 8 (2) ◽  
pp. 1001-1005 ◽  
Author(s):  
J Tower ◽  
B Sollner-Webb
Keyword(s):  
Rna Polymerase ◽  
Stationary Phase ◽  
Rna Polymerase Iii ◽  
Control Cell ◽  
Rna Polymerase I ◽  
Rdna Transcription ◽  
Down Regulation ◽  
Cell Extracts ◽  
Polymerase Iii ◽  
Polymerase I

Extracts of cells that are down-regulated for transcription by RNA polymerase I and RNA polymerase III exhibit a reduced in vitro transcriptional capacity. We have recently demonstrated that the down-regulation of polymerase I transcription in extracts of cycloheximide-treated and stationary-phase cells results from a lack of an activated subform of RNA polymerase I which is essential for rDNA transcription. To examine whether polymerase III transcriptional down-regulation occurs by a similar mechanism, the polymerase III transcription factors were isolated and added singly and in pairs to control cell extracts and to extracts of cells that had reduced polymerase III transcriptional activity due to cycloheximide treatment or growth into stationary phase. These down-regulations result from a specific reduction in TFIIIB; TFIIIC and polymerase III activities remain relatively constant. Thus, although transcription by both polymerase III and polymerase I is substantially decreased in extracts of growth-arrested cells, this regulation is brought about by reduction of different kinds of activities: a component of the polymerase III stable transcription complex in the former case and the activated subform of RNA polymerase I in the latter.

scholarly journals Chromatin Structure and Expression of a Gene Transcribed by RNA Polymerase III Are Independent of H2A.Z Deposition

2008 ◽  
Vol 28 (8) ◽  
pp. 2598-2607 ◽  
Author(s):  
Aneeshkumar Gopalakrishnan Arimbasseri ◽  
Purnima Bhargava
Keyword(s):  
Rna Polymerase ◽  
Chromatin Structure ◽  
Rna Polymerase Iii ◽  
Nutritional Deprivation ◽  
U6 Snrna ◽  
Polymerase Iii ◽  
Downstream Box ◽  
Pol Iii

ABSTRACT The genes transcribed by RNA polymerase III (Pol III) generally have intragenic promoter elements. One of them, the yeast U6 snRNA (SNR6) gene is activated in vitro by a positioned nucleosome between its intragenic box A and extragenic, downstream box B separated by ∼200 bp. We demonstrate here that the in vivo chromatin structure of the gene region is characterized by the presence of an array of positioned nucleosomes, with only one of them in the 5′ end of the gene having a regulatory role. A positioned nucleosome present between boxes A and B in vivo does not move when the gene is repressed due to nutritional deprivation. In contrast, the upstream nucleosome which covers the TATA box under repressed conditions is shifted ∼50 bp further upstream by the ATP-dependent chromatin remodeler RSC upon activation. It is marked with the histone variant H2A.Z and H4K16 acetylation in active state. In the absence of H2A.Z, the chromatin structure of the gene does not change, suggesting that H2A.Z is not required for establishing the active chromatin structure. These results show that the chromatin structure directly participates in regulation of a Pol III-transcribed gene under different states of its activity in vivo.

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