The Localization of Nuclear DNA Helicase II in Different Nuclear Compartments Is Linked to Transcription

2002 ◽  
Vol 279 (2) ◽  
pp. 260-270 ◽  
Author(s):  
B. Fuchsová ◽  
P. Hozák
Keyword(s):  
Nuclear Dna ◽  
Dna Helicase ◽  
Dna Helicase Ii ◽  
Nuclear Compartments

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.

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 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.

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