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Your search keyword '"V. Philimonenko"' showing total 3 results
Start Over Author "V. Philimonenko" Journal nature cell biology
3 results on '"V. Philimonenko"'

1. Nuclear actin and myosin I are required for RNA polymerase I transcription

Author

Wilma A. Hofmann, Hana Dingová, Ingrid Grummt, Katarína Kyselá, Michal Kahle, Pavel Hozák, Hanswalter Zentgraf, Sebastian Iben, Primal de Lanerolle, Vlada V. Philimonenko, and Jian Zhao

Subjects
Transcription, Genetic, Recombinant Fusion Proteins, macromolecular substances, Biology, DNA, Ribosomal, Antibodies, Cell Line, Myosin Type I, Transcription (biology), RNA Polymerase I, Cell Line, Tumor, Myosin, medicine, RNA polymerase I, Serine, Humans, Transcription factor, Cell Nucleus, Ribosomal Protein S6 Kinases, RNA, Cell Biology, Molecular biology, Actins, Chromatin, Cell biology, Cell nucleus, medicine.anatomical_structure, Pol1 Transcription Initiation Complex Proteins, RNA, Ribosomal, RNA Interference, Protein Kinases, Protein Binding, Transcription Factors
Abstract

The presence of actin and nuclear myosin I (NMI) in the nucleus suggests a role for these motor proteins in nuclear functions. We have investigated the role of actin and nuclear myosin I (NMI) in the transcription of ribosomal RNA genes (rDNA). Both proteins are associated with rDNA and are required for RNA polymerase I (Pol I) transcription. Microinjection of antibodies against actin or NMI, as well as short interfering RNA-mediated depletion of NMI, decreased Pol I transcription in vivo, whereas overexpression of NMI augmented pre-rRNA synthesis. In vitro, recombinant NMI activated Pol I transcription, and antibodies to NMI or actin inhibited Pol I transcription both on naked DNA and pre-assembled chromatin templates. Whereas actin associated with Pol I, NMI bound to Pol I through the transcription-initiation factor TIF-IA. The association with Pol I requires phosphorylation of TIF-IA at Ser 649 by RSK kinase, indicating a role for NMI in the growth-dependent regulation of rRNA synthesis.

Published
2004

2. Actin is part of pre-initiation complexes and is necessary for transcription by RNA polymerase II

Author

Katarína Kyselá, Beata Fuchsova, Wilma A. Hofmann, Vlada V. Philimonenko, James A. Goodrich, Primal de Lanerolle, Evangelos Mavrommatis, Pavel Hozák, Gabriela M. Vargas, James L. Lessard, Thomas J. Hope, and Ljuba Stojiljkovic

Subjects
Transcription factories, Transcription, Genetic, RNA polymerase II, macromolecular substances, Mitochondrial Proteins, Humans, Actin-binding protein, Promoter Regions, Genetic, RNA polymerase II holoenzyme, DNA Primers, biology, General transcription factor, Base Sequence, Nuclear Proteins, Proteins, Cell Biology, Molecular biology, Actins, Cell biology, biology.protein, Trans-Activators, Transcription factor II F, RNA Polymerase II, Transcription factor II D, Transcription factor II B, HeLa Cells
Abstract

Actin is abundant in the nucleus and has been implicated in transcription; however, the nature of this involvement has not been established. Here we demonstrate that beta-actin is critically involved in transcription because antibodies directed against beta-actin, but not muscle actin, inhibited transcription in vivo and in vitro. Chromatin immunoprecipitation assays demonstrated the recruitment of actin to the promoter region of the interferon-gamma-inducible MHC2TA gene as well as the interferon-alpha-inducible G1P3 gene. Further investigation revealed that actin and RNA polymerase II co-localize in vivo and also co-purify. We employed an in vitro system with purified nuclear components to demonstrate that antibodies to beta-actin block the initiation of transcription. This assay also demonstrates that beta-actin stimulates transcription by RNA polymerase II. Finally, DNA-binding experiments established the presence of beta-actin in pre-initiation complexes and also showed that the depletion of actin prevented the formation of pre-initiation complexes. Together, these data suggest a fundamental role for actin in the initiation of transcription by RNA polymerase II.

Published
2004

3. Actin is part of pre-initiation complexes and is necessary for transcription by RNA polymerase II.

Author

Hofmann WA, Stojiljkovic L, Fuchsova B, Vargas GM, Mavrommatis E, Philimonenko V, Kysela K, Goodrich JA, Lessard JL, Hope TJ, Hozak P, and de Lanerolle P

Subjects
Base Sequence, DNA Primers, HeLa Cells, Humans, Mitochondrial Proteins, Nuclear Proteins genetics, Promoter Regions, Genetic, Proteins genetics, Trans-Activators genetics, Actins physiology, RNA Polymerase II physiology, Transcription, Genetic physiology
Abstract

Actin is abundant in the nucleus and has been implicated in transcription; however, the nature of this involvement has not been established. Here we demonstrate that beta-actin is critically involved in transcription because antibodies directed against beta-actin, but not muscle actin, inhibited transcription in vivo and in vitro. Chromatin immunoprecipitation assays demonstrated the recruitment of actin to the promoter region of the interferon-gamma-inducible MHC2TA gene as well as the interferon-alpha-inducible G1P3 gene. Further investigation revealed that actin and RNA polymerase II co-localize in vivo and also co-purify. We employed an in vitro system with purified nuclear components to demonstrate that antibodies to beta-actin block the initiation of transcription. This assay also demonstrates that beta-actin stimulates transcription by RNA polymerase II. Finally, DNA-binding experiments established the presence of beta-actin in pre-initiation complexes and also showed that the depletion of actin prevented the formation of pre-initiation complexes. Together, these data suggest a fundamental role for actin in the initiation of transcription by RNA polymerase II.

Published
2004
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