Association of human DNA helicase RecQ5β with RNA polymerase II and its possible role in transcription

2008 ◽  
Vol 413 (3) ◽  
pp. 505-516 ◽  
Author(s):  
Keiichi Izumikawa ◽  
Mitsuaki Yanagida ◽  
Toshiya Hayano ◽  
Hiroyuki Tachikawa ◽  
Wataru Komatsu ◽  
...  

Although RecQ5β is a ssDNA (single-stranded DNA)-stimulated ATPase and an ATP-dependent DNA helicase with strand-annealing activities, its cellular function remains to be explored. In the present paper, we used immunopurification and MS-based analyses to show that human DNA helicase RecQ5β is associated with at least four RNAP II (RNA polymerase II) subunits. RecQ5β was also present in complexes immunoprecipitated using three different antibodies against the large subunit of RNAP II, or in complexes immunoprecipitated using an anti-FLAG antibody against either FLAG–RNAP II 33 kDa subunit or FLAG–Pin1. Different regions of the non-helicase domain of the RecQ5β molecule were associated with hypophosphorylated and hyperphosphorylated forms of the RNAP II large subunit independently of DNA and RNA. RecQ5β was also found in nuclear chromatin fractions and associated with the coding regions of the LDL (low-density lipoprotein) receptor and β-actin genes. Knockdown of the RecQ5β transcript increased the transcription of those genes. The results of the present study suggest that RecQ5β has suppressive roles in events associated with RNAP II-dependent transcription.

1998 ◽  
Vol 18 (7) ◽  
pp. 4291-4300 ◽  
Author(s):  
Michael C. Edwards ◽  
Calvin Wong ◽  
Stephen J. Elledge

ABSTRACT The gene coding for human cyclin K was isolated as aCPR (cell-cycle progression restoration) gene by virtue of its ability to impart a Far− phenotype to the budding yeast Saccharomyces cerevisiae and to rescue the lethality of a deletion of the G1 cyclin genes CLN1,CLN2, and CLN3. The cyclin K gene encodes a 357-amino-acid protein most closely related to human cyclins C and H, which have been proposed to play a role in regulating basal transcription through their association with and activation of cyclin-dependent kinases (Cdks) that phosphorylate the carboxyl-terminal domain (CTD) of the large subunit of RNA polymerase II (RNAP II). Murine and Drosophila melanogaster homologs of cyclin K have also been identified. Cyclin K mRNA is ubiquitously expressed in adult mouse and human tissues, but is most abundant in the developing germ cells of the adult testis and ovaries. Cyclin K is associated with potent CTD kinase and Cdk kinase (CAK) activity in vitro and coimmunoprecipitates with the large subunit of RNAP II. Thus, cyclin K represents a new member of the “transcription” cyclin family which may play a dual role in regulating Cdk and RNAP II activity.


Diversity ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 666
Author(s):  
Phongeun Sysouphanthong ◽  
Naritsada Thongklang ◽  
Jian-Kui Liu ◽  
Else C. Vellinga

In our ongoing research on lepiotaceous taxa (Agaricaceae s.l.) in Laos and northern Thailand, we focus here on Chlorophyllum, Clarkeinda, Macrolepiota, Pseudolepiota, and Xanthagaricus. Collections were obtained from various habitats, including agricultural habitats, grasslands, and rainforests. A total of 12 taxa were examined and investigated. Of these 12, two are new for science; viz. Xanthagaricus purpureosquamulosus with brownish-grey to violet-brown squamules on a pale-violet to violet background; it shares the pileus color with X. caeruleus and X. ianthinus, but differs in other characters; and Macrolepiota excelsa, rather similar to M. procera but related toM. detersa. Two species, Pseudolepiota zangmui and Xanthagaricus necopinatus are recorded for the first time in Thailand. Four species of Chlorophyllum and a total of four species of Macrolepiota were found, viz., C. demangei and C. hortense with white basidiospores, C. molybdites and C. globosum with green basidiospores, M. detersa, M. dolichaula, the new M. excelsa, and M. velosa. Another rather common striking species is Clarkeinda trachodes, with yellow-green basidiospores. Each species is described in detail, with color photographs and line drawings. Phylogenetic analyses based on internal transcribed spacer (nrITS) region, the large subunit nuclear ribosomal (nrLSU) DNA and RNA polymerase II second largest subunit (rpb2) genes provide evidence for the placement of the species covered.


2001 ◽  
Vol 75 (20) ◽  
pp. 9872-9884 ◽  
Author(s):  
H. L. Jenkins ◽  
C. A. Spencer

ABSTRACT During lytic infection, herpes simplex virus type 1 (HSV-1) represses host transcription, recruits RNA polymerase II (RNAP II) to viral replication compartments, and alters the phosphorylation state of the RNAP II large subunit. Host transcription repression and RNAP II modifications require expression of viral immediate-early (IE) genes. Efficient modification of the RNAP II large subunit to the intermediately phosphorylated (IIi) form requires expression of ICP22 and the UL13 kinase. We have further investigated the mechanisms by which HSV-1 effects global changes in RNAP II transcription by analyzing the RNAP II holoenzyme. We find that the RNAP II general transcription factors (GTFs) remain abundant after infection and are recruited into viral replication compartments, suggesting that they continue to be involved in viral gene transcription. However, virus infection modifies the composition of the RNAP II holoenzyme, in particular triggering the loss of the essential GTF, TFIIE. Loss of TFIIE from the RNAP II holoenzyme requires viral IE gene expression, and viral IE proteins may be redundant in mediating this effect. Although viral IE proteins do not associate with the RNAP II holoenzyme, they interact with RNAP II in complexes of lower molecular mass. As the RNAP II holoenzyme containing TFIIE is necessary for activated transcription initiation and RNAP II large subunit phosphorylation in uninfected cells, virus-induced modifications to the holoenzyme may affect both of these processes, leading to aberrant phosphorylation of the RNAP II large subunit and repression of host gene transcription.


2005 ◽  
Vol 79 (24) ◽  
pp. 15477-15493 ◽  
Author(s):  
Sama Tamrakar ◽  
Anokhi J. Kapasi ◽  
Deborah H. Spector

ABSTRACT Human cytomegalovirus infection in the presence of the cyclin-dependent kinase (cdk) inhibitor roscovitine leads to changes in differential splicing and the polyadenylation of immediate early IE1/IE2 and UL37 transcripts (V. Sanchez, A. K. McElroy, J. Yen, S. Tamrakar, C. L. Clark, R. A. Schwartz, and D. H. Spector, J. Virol. 78:11219-11232, 2004). To determine if this was associated with specific phosphorylation of the C-terminal domain (CTD) of the RNA polymerase II (RNAP II) large subunit by cdk7/cyclin H and cdk9/cyclin T1, we examined the expression and localization of these kinases and the various phosphorylated forms of RNAP II. Infection resulted in increased RNAP II CTD phosphorylated on serines 2 and 5 and increased levels of activity of cdk7 and cdk9. At early times, cdk9 localizes with input viral DNA, and aggregates of cdk9 and cdk7 and a subset of Ser2-phosphorylated RNAP II colocalize with IE1/IE2 proteins adjacent to promyelocytic leukemia protein oncogenic domains. Later, cdk9 and Ser2-phosphorylated RNAP II form a nuclear punctate pattern; cdk7 resides in replication centers, and Ser5-phosphorylated RNAP II clusters at the peripheries of replication centers. Roscovitine treatment leads to decreased levels of hyperphosphorylated RNAP II (RNAP IIo) in infected cells and of hypophosphorylated RNAP II in mock-infected and infected cells. The RNAP IIo decrease does not occur if roscovitine is added 8 h postinfection, as was previously observed for processing of IE transcripts. These results suggest that accurate IE gene expression requires specific phosphorylation of the RNAP II CTD early in infection.


1996 ◽  
Vol 16 (7) ◽  
pp. 3361-3369 ◽  
Author(s):  
R Baskaran ◽  
G G Chiang ◽  
J Y Wang

The c-abl proto-oncogene encodes a nuclear tyrosine kinase that can phosphorylate the mammalian RNA polymerase II (RNAP II) on its C-terminal repeated domain (CTD) in vitro. Phosphorylation of the CTD has previously been shown to require the tyrosine kinase and the SH2 domain of Abl. We show here that a CTD-interacting domain (CTD-ID) at the C-terminal region of c-Abl is also required. Deletion of the CTD-ID causes the Km 0.4 microM to increase by 2 orders of magnitude. Direct binding of the CTD-ID to CTD and to RNAP II could be demonstrated in vitro. Phosphorylation of a recombinant glutathione S-transferase-CTD by c-Abl was observed in cotransfected COS cells. Mutant Abl proteins lacking the CTD-ID, while capable of autophosphorylation, neither phosphorylated nor associated with the glutathione S-transferase-CTD in vivo. Transient overexpression of c-Abl also led to a four- to fivefold increase in the phosphotyrosine content of the RNAP II large subunit. Moreover, the large subunit of RNAP II could be coprecipitated with c-Abl. Tyrosine phosphorylation of the coprecipitated RNAP II was again dependent on the presence of the CTD-ID in Abl. Finally, the ability of c-Abl to phosphorylate and associate with RNAP II could be correlated with the enhancement of transcription by c-Abl in transient cotransfection assays. Taken together, these observations demonstrate that c-Abl can function as a CTD kinase in vitro as well as in vivo.


2005 ◽  
Vol 83 (4) ◽  
pp. 497-504 ◽  
Author(s):  
Benoit Coulombe ◽  
Marie-France Langelier

High resolution X-ray crystal structures of multisubunit RNA polymerases (RNAP) have contributed to our understanding of transcriptional mechanisms. They also provided a powerful guide for the design of experiments aimed at further characterizing the molecular stages of the transcription reaction. Our laboratory used tandem-affinity peptide purification in native conditions to isolate human RNAP II variants that had site-specific mutations in structural elements located strategically within the enzyme's catalytic center. Both in vitro and in vivo analyses of these mutants revealed novel features of the catalytic mechanisms involving this enzyme.Key words: RNA polymerase II, transcriptional mechanisms, mutational analysis, mRNA synthesis.


2021 ◽  
Author(s):  
Blase Matthew LeBlanc ◽  
Rosamaria Yvette Moreno ◽  
Edwin Escobar ◽  
Mukesh Kumar Venkat Ramani ◽  
Jennifer S Brodbelt ◽  
...  

RNA polymerase II (RNAP II) is one of the primary enzymes responsible for expressing protein-encoding genes and some small nuclear RNAs. The enigmatic carboxy-terminal domain (CTD) of RNAP II and...


2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Livia Eiselleova ◽  
Viktor Lukjanov ◽  
Simon Farkas ◽  
David Svoboda ◽  
Karel Stepka ◽  
...  

The eukaryotic nucleus is a highly complex structure that carries out multiple functions primarily needed for gene expression, and among them, transcription seems to be the most fundamental. Diverse approaches have demonstrated that transcription takes place at discrete sites known as transcription factories, wherein RNA polymerase II (RNAP II) is attached to the factory and immobilized while transcribing DNA. It has been proposed that transcription factories promote chromatin loop formation, creating long-range interactions in which relatively distant genes can be transcribed simultaneously. In this study, we examined long-range interactions between the POU5F1 gene and genes previously identified as being POU5F1 enhancer-interacting, namely, CDYL, TLE2, RARG, and MSX1 (all involved in transcriptional regulation), in human pluripotent stem cells (hPSCs) and their early differentiated counterparts. As a control gene, RUNX1 was used, which is expressed during hematopoietic differentiation and not associated with pluripotency. To reveal how these long-range interactions between POU5F1 and the selected genes change with the onset of differentiation and upon RNAP II inhibition, we performed three-dimensional fluorescence in situ hybridization (3D-FISH) followed by computational simulation analysis. Our analysis showed that the numbers of long-range interactions between specific genes decrease during differentiation, suggesting that the transcription of monitored genes is associated with pluripotency. In addition, we showed that upon inhibition of RNAP II, long-range associations do not disintegrate and remain constant. We also analyzed the distance distributions of these genes in the context of their positions in the nucleus and revealed that they tend to have similar patterns resembling normal distribution. Furthermore, we compared data created in vitro and in silico to assess the biological relevance of our results.


2010 ◽  
Vol 30 (21) ◽  
pp. 5180-5193 ◽  
Author(s):  
Alicia García ◽  
Emanuel Rosonina ◽  
James L. Manley ◽  
Olga Calvo

ABSTRACT The transcriptional coactivator Sub1 has been implicated in several aspects of mRNA metabolism in yeast, such as activation of transcription, termination, and 3′-end formation. Here, we present evidence that Sub1 plays a significant role in controlling phosphorylation of the RNA polymerase II large subunit C-terminal domain (CTD). We show that SUB1 genetically interacts with the genes encoding all four known CTD kinases, SRB10, KIN28, BUR1, and CTK1, suggesting that Sub1 acts to influence CTD phosphorylation at more than one step of the transcription cycle. To address this directly, we first used in vitro kinase assays, and we show that, on the one hand, SUB1 deletion increased CTD phosphorylation by Kin28, Bur1, and Ctk1 but, on the other, it decreased CTD phosphorylation by Srb10. Second, chromatin immunoprecipitation assays revealed that SUB1 deletion decreased Srb10 chromatin association on the inducible GAL1 gene but increased Kin28 and Ctk1 chromatin association on actively transcribed genes. Taken together, our data point to multiple roles for Sub1 in the regulation of CTD phosphorylation throughout the transcription cycle.


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