Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.6 (RNA polymerase)
 34,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Messenger RNAs for several components of the transcriptional apparatus are greatly overexpressed in postmeiotic male germ cells in rodents (Schmidt and Schibler, Development 1995; 121:2373-2383). Because of the tight coupling of polyadenylation and transcription, we examined expression in germ cells of mRNAs for key polyadenylation factors. The mRNA for the 64 000 M(r) subunit of the cleavage stimulation factor (CstF-64) was expressed at least 250-fold greater in mouse testicular RNA than in liver RNA. RNA blot analysis showed that the mRNA for the 160 000 M(r) subunit of the cleavage and polyadenylation specificity factor was similarly overexpressed, as was the mRNA for the large subunit of RNA polymerase II. General transcription factors, such as the TATA-binding protein and transcription factor IIH, and splicing factors, such as components of the small nuclear ribonucleoproteins, were also expressed in meiotic and postmeiotic germ cells. The X-linked CstF-64 protein is expressed before and after but not during meiosis in the mouse (Wallace et al., Proc Natl Acad Sci U S A 1999; 96:6763-6768), which suggests that overexpression of mRNA transcription and processing factors plays an essential role in postmeiotic germ cell mRNA metabolism.
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PMID:Overexpression of the CstF-64 and CPSF-160 polyadenylation protein messenger RNAs in mouse male germ cells. 1136 1

Transcription and processing of mRNA precursors are coordinated events that require numerous complex interactions to ensure that they are successfully executed. We described previously an unexpected association between a transcription factor, PC4 (or Sub1 in yeast), and an mRNA polyadenylation factor, CstF-64 (Rna15 in yeast), and provided evidence that this was important for efficient transcription elongation. Here we provide insight into the mechanism by which this occurs. We show that Sub1 and Rna15 are recruited to promoters and present along the length of several yeast genes. Allele-specific genetic interactions between SUB1 and genes encoding an RNA polymerase II (RNAP II)-specific kinase (KIN28) and phosphatase (FCP1) suggest that Sub1 influences and/or is sensitive to the phosphorylation status of elongating RNAP II. Remarkably, we find that cells lacking Sub1 display decreased accumulation of Fcp1, altered RNAP II phosphorylation and decreased crosslinking of RNAP II to transcribed genes. Our data provide evidence that Rna15 and Sub1 are present along the length of several genes and that Sub1 facilitates elongation by influencing enzymes that modify RNAP II.
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PMID:The transcriptional coactivator PC4/Sub1 has multiple functions in RNA polymerase II transcription. 1569 59

DDX1 bodies, cleavage bodies, Cajal bodies (CBs), and gems are nuclear suborganelles that contain factors involved in RNA transcription and/or processing. Although all four nuclear bodies can exist as distinct entities, they often colocalize or overlap with each other. To better understand the relationship between these four nuclear bodies, we examined their spatial distribution as a function of the cell cycle. Here, we report that whereas DDX1 bodies, CBs and gems are present throughout interphase, CPSF-100-containing cleavage bodies are predominantly found during S and G2 phases, whereas CstF-64-containing cleavage bodies are primarily observed during S phase. All four nuclear bodies associate with each other during S phase, with cleavage bodies colocalizing with DDX1 bodies, and cleavage bodies/DDX1 bodies residing adjacent to gems and CBs. Although inhibitors of RNA transcription had no effect on DDX1 bodies or cleavage bodies, inhibitors of DNA replication resulted in loss of CstF-64-containing cleavage bodies. A striking effect on nuclear structures was observed with latrunculin B, an inhibitor of actin polymerization, resulting in the formation of needlelike nuclear spicules made up of CstF-64, CPSF-100, RNA, and RNA polymerase II. Our results suggest that cleavage body components are highly dynamic in nature.
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PMID:Dynamic nature of cleavage bodies and their spatial relationship to DDX1 bodies, Cajal bodies, and gems. 1637 7

Yeast Rna15 and its vertebrate orthologue CstF-64 play critical roles in mRNA 3 '-end processing and in transcription termination downstream of poly(A) sites. These proteins contain N-terminal domains that recognize the poly(A) site, but little is known about their highly conserved C-terminal regions. Here we show by NMR that the C-terminal domains of CstF-64 and Rna15 fold into a three-helix bundle with an uncommon topological arrangement. The structure defines a cluster of evolutionary conserved yet exposed residues we show to be essential for the interaction between Pcf11 and Rna15. Furthermore, we demonstrate that this interaction is critical for the function of Rna15 in 3 '-end processing but dispensable for transcription termination. The C-terminal domain of the Rna15 homologue Pti1 contains critical sequence alterations within this region that are predicted to prevent Pcf11 interaction, providing an explanation for the distinct functions of these two closely related proteins in the 3 '-end formation of RNA polymerase II transcripts. These results define the role of the C-terminal half of Rna15 and provide insight into the network of protein/protein interactions responsible for assembly of the 3 '-end processing apparatus.
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PMID:The C-terminal domains of vertebrate CstF-64 and its yeast orthologue Rna15 form a new structure critical for mRNA 3'-end processing. 1711 58

We reported previously that when cells are arrested in S phase, a subset of p53 target genes fails to be strongly induced despite the presence of high levels of p53. When DNA replication is inhibited, reduced p21 mRNA accumulation is correlated with a marked reduction in transcription elongation. Here we show that ablation of the protein kinase Chk1 rescues the p21 transcription elongation defect when cells are blocked in S phase, as measured by increases in both p21 mRNA levels and the presence of the elongating form of RNA polymerase II (RNAPII) toward the 3' end of the p21 gene. Recruitment of specific elongation and 3' processing factors (DSIF, CstF-64, and CPSF-100) is also restored. While additional components of the RNAPII transcriptional machinery, such as TFIIB and CDK7, are recruited more extensively to the p21 locus after DNA damage than after replication stress, their recruitment is not enhanced by ablation of Chk1. Significantly, ablating Chk2, a kinase closely related in substrate specificity to Chk1, does not rescue p21 mRNA levels during S-phase arrest. Thus, Chk1 has a direct and selective role in the elongation block to p21 observed during S-phase arrest. These findings demonstrate for the first time a link between the replication checkpoint mediated by ATR/Chk1 and the transcription elongation/3' processing machinery.
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PMID:A role for Chk1 in blocking transcriptional elongation of p21 RNA during the S-phase checkpoint. 1948 75

Immunoglobulin secretion is modulated by competition between the use of a weak promoter-proximal poly(A) site and a nonconsensus splice site in the final secretory-specific exon of the heavy chain pre-mRNA. The RNA polymerase II transcription elongation factor ELL2, which is induced in plasma cells, enhanced both polyadenylation and exon skipping with the gene encoding the immunoglobulin heavy-chain complex (Igh) and reporter constructs. Lowering ELL2 expression by transfection of heterogenous ribonucleoprotein F (hnRNP F) or small interfering RNA resulted in lower abundance of secretory-specific forms of immunoglobulin heavy-chain mRNA. ELL2 and the polyadenylation factor CstF-64 tracked together with RNA polymerase II across the Igh mu- and gamma-gene segments; the association of both factors was blocked by ELL2-specific small interfering RNA. Thus, loading of ELL2 and CstF-64 on RNA polymerase II was linked, caused enhanced use of the proximal poly(A) site and was necessary for processing of immunoglobulin heavy-chain mRNA.
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PMID:Transcription elongation factor ELL2 directs immunoglobulin secretion in plasma cells by stimulating altered RNA processing. 1974 64

The general transcription factor TFIIB plays a central role in preinitiation complex (PIC) assembly and the recruitment of RNA polymerase II (RNA pol II) to the promoter. Recent studies have revealed that TFIIB engages in contact with the transcription termination region and also with complexes that are involved in 3' end processing and/or termination. Here we report that TFIIB can be phosphorylated within the N terminus at serine 65 in vivo and that the phosphorylated form of TFIIB is present within (PICs). Surprisingly, TFIIB serine 65 phosphorylation is required after the phosphorylation of serine 5 of RNA pol II C-terminal domain (CTD) has occurred, but before productive transcription initiation begins. We show that phosphorylation of TFIIB at serine 65 regulates the interaction between TFIIB and the CstF-64 component of the CstF 3' cleavage and polyadenylation complex. This directs the recruitment of CstF (cleavage stimulatory factor) to the terminator and also the recruitment of the CstF and CPSF (cleavage and polyadenylation specific factor) complexes to the promoter. Our results reveal that phosphorylation of TFIIB is a critical event in transcription that links the gene promoter and terminator and triggers initiation by RNA pol II.
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PMID:Phosphorylation of TFIIB links transcription initiation and termination. 2022 68