scholarly journals Transcription elongation factor SII interacts with a domain of the large subunit of human RNA polymerase II.

1988 ◽  
Vol 8 (8) ◽  
pp. 3136-3142 ◽  
Author(s):  
J Rappaport ◽  
K Cho ◽  
A Saltzman ◽  
J Prenger ◽  
M Golomb ◽  
...  

Genomic sequences for the large subunit of human RNA polymerase II corresponding to a part of the fifth exon were inserted into an expression vector at the carboxy-terminal end of the beta-galactosidase gene. The in-frame construct produced a 125-kilodalton fusion protein, containing approximately 10 kilodaltons of the large subunit of RNA polymerase II and 116 kilodaltons of beta-galactosidase. The purified bacterially produced fusion protein inhibited specific transcription from the adenovirus type 2 major late promoter, while beta-galactosidase had no effect. This effect of the fusion protein was during RNA elongation, not at the level of initiation, resembling the faithfully initiated but incomplete transcripts produced with purified factors in the absence of SII. Similarly, monoclonal antibody 2-7B, which reacts with the RNA polymerase II region represented in the fusion protein, inhibited specific transcription at the level of elongation in a whole-cell extract. Both monoclonal antibody 2-7B and the fusion protein, although unable to inhibit purified RNA polymerase II in a nonspecific transcription assay, selectively blocked the stimulation elicited by transcription elongation factor SII on the activity of the purified enzyme in vitro. This suggests that the fusion protein traps the SII in nonstimulatory interactions and that antibody 2-7B inhibits SII binding to RNA polymerase II. Thus, this suggests that an SII-binding contact required for specific RNA elongation resides within the fifth exon region of the largest RNA polymerase II subunit.

1988 ◽  
Vol 8 (8) ◽  
pp. 3136-3142
Author(s):  
J Rappaport ◽  
K Cho ◽  
A Saltzman ◽  
J Prenger ◽  
M Golomb ◽  
...  

Genomic sequences for the large subunit of human RNA polymerase II corresponding to a part of the fifth exon were inserted into an expression vector at the carboxy-terminal end of the beta-galactosidase gene. The in-frame construct produced a 125-kilodalton fusion protein, containing approximately 10 kilodaltons of the large subunit of RNA polymerase II and 116 kilodaltons of beta-galactosidase. The purified bacterially produced fusion protein inhibited specific transcription from the adenovirus type 2 major late promoter, while beta-galactosidase had no effect. This effect of the fusion protein was during RNA elongation, not at the level of initiation, resembling the faithfully initiated but incomplete transcripts produced with purified factors in the absence of SII. Similarly, monoclonal antibody 2-7B, which reacts with the RNA polymerase II region represented in the fusion protein, inhibited specific transcription at the level of elongation in a whole-cell extract. Both monoclonal antibody 2-7B and the fusion protein, although unable to inhibit purified RNA polymerase II in a nonspecific transcription assay, selectively blocked the stimulation elicited by transcription elongation factor SII on the activity of the purified enzyme in vitro. This suggests that the fusion protein traps the SII in nonstimulatory interactions and that antibody 2-7B inhibits SII binding to RNA polymerase II. Thus, this suggests that an SII-binding contact required for specific RNA elongation resides within the fifth exon region of the largest RNA polymerase II subunit.


2009 ◽  
Vol 425 (2) ◽  
pp. 373-380 ◽  
Author(s):  
Sabine Wenzel ◽  
Berta M. Martins ◽  
Paul Rösch ◽  
Birgitta M. Wöhrl

The eukaryotic transcription elongation factor DSIF [DRB (5,6-dichloro-1-β-D-ribofuranosylbenzimidazole) sensitivity-inducing factor] is composed of two subunits, hSpt4 and hSpt5, which are homologous to the yeast factors Spt4 and Spt5. DSIF is involved in regulating the processivity of RNA polymerase II and plays an essential role in transcriptional activation of eukaryotes. At several eukaryotic promoters, DSIF, together with NELF (negative elongation factor), leads to promoter-proximal pausing of RNA polymerase II. In the present paper we describe the crystal structure of hSpt4 in complex with the dimerization region of hSpt5 (amino acids 176–273) at a resolution of 1.55 Å (1 Å=0.1 nm). The heterodimer shows high structural similarity to its homologue from Saccharomyces cerevisiae. Furthermore, hSpt5-NGN is structurally similar to the NTD (N-terminal domain) of the bacterial transcription factor NusG. A homologue for hSpt4 has not yet been found in bacteria. However, the archaeal transcription factor RpoE” appears to be distantly related. Although a comparison of the NusG-NTD of Escherichia coli with hSpt5 revealed a similarity of the three-dimensional structures, interaction of E. coli NusG-NTD with hSpt4 could not be observed by NMR titration experiments. A conserved glutamate residue, which was shown to be crucial for dimerization in yeast, is also involved in the human heterodimer, but is substituted for a glutamine residue in Escherichia coli NusG. However, exchanging the glutamine for glutamate proved not to be sufficient to induce hSpt4 binding.


2000 ◽  
Vol 20 (4) ◽  
pp. 1263-1270 ◽  
Author(s):  
Akira Ishiguro ◽  
Yasuhisa Nogi ◽  
Koji Hisatake ◽  
Masami Muramatsu ◽  
Akira Ishihama

ABSTRACT The Rpb6 subunit of RNA polymerase II is one of the five subunits common to three forms of eukaryotic RNA polymerase. Deletion and truncation analyses of the rpb6 gene in the fission yeastSchizosaccharomyces pombe indicated that Rpb6, consisting of 142 amino acid residues, is an essential protein for cell viability, and the essential region is located in the C-terminal half between residues 61 and 139. After random mutagenesis, a total of 14 temperature-sensitive mutants were isolated, each carrying a single (or double in three cases and triple in one) mutation. Four mutants each carrying a single mutation in the essential region were sensitive to 6-azauracil (6AU), which inhibits transcription elongation by depleting the intracellular pool of GTP and UTP. Both 6AU sensitivity and temperature-sensitive phenotypes of these rpb6 mutants were suppressed by overexpression of TFIIS, a transcription elongation factor. In agreement with the genetic studies, the mutant RNA polymerases containing the mutant Rpb6 subunits showed reduced affinity for TFIIS, as measured by a pull-down assay of TFIIS-RNA polymerase II complexes using a fusion form of TFIIS with glutathioneS-transferase. Moreover, the direct interaction between TFIIS and RNA polymerase II was competed by the addition of Rpb6. Taken together, the results lead us to propose that Rpb6 plays a role in the interaction between RNA polymerase II and the transcription elongation factor TFIIS.


2020 ◽  
Author(s):  
Jennifer J. Chen ◽  
Jean Mbogning ◽  
Mark A. Hancock ◽  
Dorsa Majdpour ◽  
Manan Madhok ◽  
...  

AbstractRtf1 is a conserved RNA polymerase II (RNAPII) elongation factor that promotes co-transcriptional histone modification, RNAPII transcript elongation, and mRNA processing. Rtf1 function requires phosphorylation of Spt5, an essential RNAPII processivity factor. Spt5 is phosphorylated within its C-terminal domain (CTD) by cyclin-dependent kinase 9 (Cdk9), catalytic component of positive transcription elongation factor b (P-TEFb). Rtf1 recognizes phosphorylated Spt5 (pSpt5) through its Plus3 domain. Since Spt5 is a unique target of Cdk9, and Rtf1 is the only known pSpt5-binding factor, the Plus3/pSpt5 interaction is thought to be a key Cdk9-dependent event regulating RNAPII elongation. Here we dissect Rtf1 regulation by pSpt5 in the fission yeast Schizosaccharomyces pombe. We demonstrate that the Plus3 domain of Rtf1 (Prf1 in S. pombe) and pSpt5 are functionally distinct, and that they act in parallel to promote Prf1 function. This alternate Plus3 domain function involves an interface that overlaps with the pSpt5 binding site and that can interact with single-stranded nucleic acid or with the Polymerase Associated Factor (PAF) Complex in vitro. We further show that the C-terminal region of Prf1, which also interacts with PAF, has a similar parallel function with pSpt5. Our results elucidate unexpected complexity underlying Cdk9-dependent pathways that regulate transcription elongation.


2013 ◽  
Vol 33 (16) ◽  
pp. 3259-3273 ◽  
Author(s):  
Manasi K. Mayekar ◽  
Richard G. Gardner ◽  
Karen M. Arndt

Transcription elongation factors associate with RNA polymerase II and aid its translocation through chromatin. One such factor is the conserved Paf1 complex (Paf1C), which regulates gene expression through several mechanisms, including the stimulation of cotranscriptional histone modifications. Previous studies revealed a prominent role for the Rtf1 subunit in tethering Paf1C to the RNA polymerase II elongation machinery. Here, we investigated the mechanism by which Rtf1 couples Paf1C to active chromatin. We show that a highly conserved domain of Rtf1 is necessary and sufficient for mediating a physical interaction between Rtf1 and the essential transcription elongation factor Spt5. Mutations that alter this Rtf1 domain or delete the Spt5 C-terminal repeat domain (CTR) disrupt the interaction between Rtf1 and Spt5 and release Paf1C from chromatin. When expressed in cells as the only source of Rtf1, the Spt5-interacting domain of Rtf1 can associate independently with active genes in a pattern similar to that of full-length Rtf1 and in a manner dependent on the Spt5 CTR.In vitroexperiments indicate that the interaction between the Rtf1 Spt5-interacting domain and the Spt5 CTR is direct. Collectively, our results provide molecular insight into a key attachment point between Paf1C and the RNA polymerase II elongation machinery.


eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Schuyler Lee ◽  
Haolin Liu ◽  
Ryan Hill ◽  
Chunjing Chen ◽  
Xia Hong ◽  
...  

More than 30% of genes in higher eukaryotes are regulated by promoter-proximal pausing of RNA polymerase II (Pol II). Phosphorylation of Pol II CTD by positive transcription elongation factor b (P-TEFb) is a necessary precursor event that enables productive transcription elongation. The exact mechanism on how the sequestered P-TEFb is released from the 7SK snRNP complex and recruited to Pol II CTD remains unknown. In this report, we utilize mouse and human models to reveal methylphosphate capping enzyme (MePCE), a core component of the 7SK snRNP complex, as the cognate substrate for Jumonji domain-containing 6 (JMJD6)’s novel proteolytic function. Our evidences consist of a crystal structure of JMJD6 bound to methyl-arginine, enzymatic assays of JMJD6 cleaving MePCE in vivo and in vitro, binding assays, and downstream effects of Jmjd6 knockout and overexpression on Pol II CTD phosphorylation. We propose that JMJD6 assists bromodomain containing 4 (BRD4) to recruit P-TEFb to Pol II CTD by disrupting the 7SK snRNP complex.


2021 ◽  
Author(s):  
Ülkü Uzun ◽  
Thomas Brown ◽  
Harry Fischl ◽  
Andrew Angel ◽  
Jane Mellor

AbstractSpt4 is a transcription elongation factor, with homologues in organisms with nucleosomes. Structural and in vitro studies implicate Spt4 in transcription through nucleosomes, yet the in vivo function of Spt4 is unclear. Here we assessed the precise position of Spt4 during transcription and the consequences of loss of Spt4 on RNA polymerase II (RNAPII) dynamics and nucleosome positioning in Saccharomyces cerevisiae. In the absence of Spt4, the spacing between gene-body nucleosomes increases and RNAPII accumulates upstream of the nucleosomal dyad, most dramatically at nucleosome +2. Spt4 associates with elongating RNAPII early in transcription and its association dynamically changes depending on nucleosome positions. Together, our data show that Spt4 regulates early elongation dynamics, participates in co-transcriptional nucleosome positioning, and promotes RNAPII movement through the gene-body nucleosomes, especially the +2 nucleosome.


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