scholarly journals Nuclear DNA helicase II is recruited to IFN-α–activated transcription sites at PML nuclear bodies

2002 ◽  
Vol 158 (3) ◽  
pp. 463-473 ◽  
Author(s):  
Beata Fuchsová ◽  
Petr Novák ◽  
Jarmila Kafková ◽  
Pavel Hozák
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Nuclear Dna ◽  
Dna Helicase ◽  
Nuclear Bodies ◽  
Interferon Α ◽  
Small Subset ◽  
Ultrastructural Studies ◽  
Dna Helicase Ii ◽  
Pml Nuclear Bodies

It is known that nuclear DNA helicase II (NDH II) links CREB-binding protein directly to RNA polymerase II holoenzyme, and that this interaction is essential for gene activation by CREB. Here, we report for the first time that some NDH II/RNA helicase A is a component of promyelocytic leukemia nuclear bodies (PML NBs). An autoimmune serum specific for PML NBs was identified and used in immunoprecipitation experiments. NDH II was present in the immunoprecipitates as shown by mass spectrometry and by immunoblotting. Immunofluorescence and ultrastructural studies showed that NDH II colocalizes with a small subset of PML NBs in control cells, however, colocalizes with practically all bodies in interferon-α–stimulated cells. After interferon stimulation, more PML NBs were found to contain newly synthesized RNA, as indicated by bromouridine incorporation. PML NBs also contain RNA polymerase II. The association of NDH II with PML NBs was transcriptionally dependent, and NDH II was present in all bodies with nascent RNA. Blocking of mRNA synthesis caused NDH II relocalization from nucleoplasm to nucleoli. Based on the data, we suggest that NDH II recruitment to PML NBs is connected with transcriptional regulation of interferon-α–inducible genes attached to PML NBs.

scholarly journals Actinomycin D Induces Histone γ-H2AX Foci and Complex Formation of γ-H2AX with Ku70 and Nuclear DNA Helicase II

2005 ◽  
Vol 280 (10) ◽  
pp. 9586-9594 ◽  
Author(s):  
Hannah Elisabeth Mischo ◽  
Peter Hemmerich ◽  
Frank Grosse ◽  
Suisheng Zhang
Keyword(s):  
Complex Formation ◽  
Actinomycin D ◽  
Nuclear Dna ◽  
Dna Helicase ◽  
Dna Helicase Ii

Multiple Functions of Nuclear DNA Helicase II (RNA Helicase A) in Nucleic Acid Metabolism

2004 ◽  
Vol 36 (3) ◽  
pp. 177-183 ◽  
Author(s):  
Suisheng Zhang ◽  
Frank Grosse
Keyword(s):  
Nuclear Dna ◽  
Rna Helicase ◽  
Dna Helicase ◽  
Nucleic Acid Metabolism ◽  
Rna Helicase A ◽  
Dna Helicase Ii ◽  
Dna And Rna ◽  
Sequence Homologies ◽  
Drosophila Protein ◽  
Purification Methods

Abstract Nuclear DNA helicase II (NDH II), or RNA helicase A (RHA), was initially discovered in mammals by conventional protein purification methods. Molecular cloning identified apparent sequence homologies between NDH II and a Drosophila protein named maleless (MLE), the latter being essential for the Drosophila X-chromosome dosage compensation. Increasing amounts of evidence suggest that NDH II is involved in multiple aspects of cellular and viral DNA and RNA metabolism. Moreover the functions of NDH II may have potential clinical implications related to viral infection, autoimmune diseases, or even tumorigenesis.

scholarly journals Phosphorylation of BLM, Dissociation from Topoisomerase IIIα, and Colocalization with γ-H2AX after Topoisomerase I-Induced Replication Damage

2005 ◽  
Vol 25 (20) ◽  
pp. 8925-8937 ◽  
Author(s):  
V. Ashutosh Rao ◽  
Angela M. Fan ◽  
LingHua Meng ◽  
Christopher F. Doe ◽  
Phillip S. North ◽  
...  
Keyword(s):  
Topoisomerase I ◽  
Protein A ◽  
Dna Helicase ◽  
Double Strand Breaks ◽  
Nuclear Bodies ◽  
H2ax Phosphorylation ◽  
Strand Breaks ◽  
Histone H2ax ◽  
Pml Nuclear Bodies ◽  
Atm Protein

ABSTRACT Topoisomerase I-associated DNA single-strand breaks selectively trapped by camptothecins are lethal after being converted to double-strand breaks by replication fork collisions. BLM (Bloom's syndrome protein), a RecQ DNA helicase, and topoisomerase IIIα (Top3α) appear essential for the resolution of stalled replication forks (Holliday junctions). We investigated the involvement of BLM in the signaling response to Top1-mediated replication DNA damage. In BLM-complemented cells, BLM colocalized with promyelocytic leukemia protein (PML) nuclear bodies and Top3α. Fibroblasts without BLM showed an increased sensitivity to camptothecin, enhanced formation of Top1-DNA complexes, and delayed histone H2AX phosphorylation (γ-H2AX). Camptothecin also induced nuclear relocalization of BLM, Top3α, and PML protein and replication-dependent phosphorylation of BLM on threonine 99 (T99p-BLM). T99p-BLM was also observed following replication stress induced by hydroxyurea. Ataxia telangiectasia mutated (ATM) protein and AT- and Rad9-related protein kinases, but not DNA-dependent protein kinase, appeared to play a redundant role in phosphorylating BLM. Following camptothecin treatment, T99p-BLM colocalized with γ-H2AX but not with Top3α or PML. Thus, BLM appears to dissociate from Top3α and PML following its phosphorylation and facilitates H2AX phosphorylation in response to replication double-strand breaks induced by Top1. A defect in γ-H2AX signaling in response to unrepaired replication-mediated double-strand breaks might, at least in part, explain the camptothecin-sensitivity of BLM-deficient cells.

scholarly journals Creb-Binding Protein (Cbp/P300) and RNA Polymerase II Colocalize in Transcriptionally Active Domains in the Nucleus

2000 ◽  
Vol 150 (1) ◽  
pp. 265-274 ◽  
Author(s):  
Anna von Mikecz ◽  
Suisheng Zhang ◽  
Marc Montminy ◽  
Eng M. Tan ◽  
Peter Hemmerich
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Active Sites ◽  
Spatial Organization ◽  
Binding Protein ◽  
Nuclear Bodies ◽  
Laser Scanning Microscopy ◽  
Creb Binding Protein ◽  
Pol Ii ◽  
Pml Bodies

The spatial organization of transcription- associated proteins is an important control mechanism of eukaryotic gene expression. Here we analyzed the nuclear distribution of the transcriptional coactivators CREB-binding protein (CBP)/p300 in situ by confocal laser scanning microscopy, and in vivo complex formation by coimmunoprecipitation. A subpopulation of CBP and p300 is targeted to active sites of transcription and partially colocalizes with hyper- and hypophosphorylated RNA polymerase II (pol II) in discrete regions of variable size throughout the nucleus. However, the coactivators were found in tight association with hypophosphorylated, but not hyperphosphorylated pol II. Transcriptional inhibition induced a relocation of CBP/p300 and pol II into speckles. Moreover, double and triple immunofluorescence analyses revealed the presence of CBP, p300, and pol II in a subset of promyelocytic leukemia (PML) bodies. Our results provide evidence for a dynamic spacial link between coactivators of transcription and the basal transcription machinery in discrete nuclear domains dependent upon the transcriptional activity of the cell. The identification of pol II in CBP/PML-containing nuclear bodies supports the idea that transcription takes place at PML bodies.

scholarly journals RNA polymerase II condensate formation and association with Cajal and histone locus bodies in living human cells

2020 ◽  
Author(s):  
Takashi Imada ◽  
Takeshi Shimi ◽  
Ai Kaiho ◽  
Yasushi Saeki ◽  
Hiroshi Kimura
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Gene Clusters ◽  
Nuclear Bodies ◽  
Histone Genes ◽  
Small Nuclear Rna ◽  
Pol Ii ◽  
Histone Locus Bodies ◽  
Dynamic Structures ◽  
Histone Locus

ABSTRACTIn eukaryotic nuclei, a number of phase-separated nuclear bodies (NBs) are present. RNA polymerase II (Pol II) is the main player in transcription and forms large condensates in addition to localizing at numerous transcription foci. Cajal bodies (CBs) and histone locus bodies (HLBs) are NBs that are involved in transcriptional and post-transcriptional regulation of small nuclear RNA and histone genes. By live-cell imaging using human HCT116 cells, we here show that Pol II condensates (PCs) nucleated near CBs and HLBs, and the number of PCs increased during S phase concomitantly with the activation period of histone genes. Ternary PC–CB– HLB associates were formed via three pathways: nucleation of PCs and HLBs near CBs, interaction between preformed PC–HLBs with CBs, and nucleation of PCs near preformed CB– HLBs. Coilin knockout increased the co-localization rate between PCs and HLBs, whereas the number, nucleation timing, and phosphorylation status of PCs remained unchanged. Depletion of PCs did not affect CBs and HLBs. Treatment with 1,6-hexanediol revealed that PCs were more liquid-like than CBs and HLBs. Thus, PCs are dynamic structures often nucleated following the activation of gene clusters associated with other NBs. (187 words)

Nucleolar localization of murine nuclear DNA helicase II (RNA helicase A)

1999 ◽  
Vol 112 (16) ◽  
pp. 2693-2703 ◽  
Author(s):  
S. Zhang ◽  
C. Herrmann ◽  
F. Grosse
Keyword(s):  
Nuclear Dna ◽  
Gene Dosage ◽  
Mammalian Species ◽  
Physiological Role ◽  
Dna Helicase ◽  
Rrna Synthesis ◽  
Nucleolar Localization ◽  
Specific Gene ◽  
Dna Helicase Ii ◽  
Pol I

Nuclear DNA helicase II (NDH II) is a highly conserved member of the DEXH superfamily of eukaryotic helicases, whose physiological role is still unclear. To explore the function of NDH II, we studied the intracellular distribution of NDH II of different mammalian species by immunofluorescence and compared these findings with the known role of the Drosophila homologue MLE that is involved in sex-specific gene dosage compensation. NDH II displayed an apparent nucleolar localization in murine cells, whereas in cells from all other mammalian species examined so far the protein was confined to the nucleoplasm and apparently excluded from the nucleoli. The nucleolar localization of mouse NDH II strongly suggests a role in ribosomal RNA biosynthesis. Immunoelectron microscopic studies revealed that the mouse NDH II was found at the dense fibrillar components of the nucleoli, and a significant percentage of NDH II molecules colocalized with the RNA polymerase I (Pol I) transcription factor UBF (upstream binding factor). Additionally, the nucleolar localization of NDH II coincided with a preferential immunolabeling pattern of nascent transcripts with bromouridine (BrUMP). Furthermore, mouse NDH II redistributed in mitosis in a manner highly correlated with Pol I activity. Conditions leading to the inhibition of Pol I activity in the interphase decreased the amount of NDH II in the nucleoli that diffused into the nucleoplasm and the cytosol. Contrary to the effect of inhibiting rRNA synthesis, treatment of mouse cells with the translation inhibitor cycloheximide did not compromise the nucleolar localization of murine NDH II.

scholarly journals Early Nuclear Events after Herpesviral Infection

2019 ◽  
Vol 8 (9) ◽  
pp. 1408 ◽  
Author(s):  
Florian Full ◽  
Armin Ensser
Keyword(s):  
Viral Genome ◽  
Nuclear Dna ◽  
Viral Gene Expression ◽  
Nuclear Bodies ◽  
Cellular Proteins ◽  
Viral Gene ◽  
Genome Replication ◽  
Tegument Proteins ◽  
Pml Nuclear Bodies ◽  
Viral Genome Replication

Herpesviruses are important pathogens that can cause significant morbidity and mortality in the human population. Herpesviruses have a double-stranded DNA genome, and viral genome replication takes place inside the nucleus. Upon entering the nucleus, herpesviruses have to overcome the obstacle of cellular proteins in order to enable viral gene expression and genome replication. In this review, we want to highlight cellular proteins that sense incoming viral genomes of the DNA-damage repair (DDR) pathway and of PML-nuclear bodies (PML-NBs) that all can act as antiviral restriction factors within the first hours after the viral genome is released into the nucleus. We show the function and significance of both nuclear DNA sensors, the DDR and PML-NBs, and demonstrate for three human herpesviruses of the alpha-, beta- and gamma-subfamilies, HSV-1, HCMV and KSHV respectively, how viral tegument proteins antagonize these pathways.

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