This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Chen, H.-K.
Right arrow Articles by Yeh, N.-H.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Chen, H.-K.
Right arrow Articles by Yeh, N.-H.

 Previous Article  |  Next Article 

Molecular and Cellular Biology, December 1999, p. 8536-8546, Vol. 19, No. 12
0270-7306/99/$04.00+0
Copyright © 1999, American Society for Microbiology. All rights reserved.

Human Nopp140, Which Interacts with RNA Polymerase I: Implications for rRNA Gene Transcription and Nucleolar Structural Organization

Hung-Kai Chen, Chi-Yun Pai,dagger Jing-Yi Huang, and Ning-Hsing Yeh*

Institute of Microbiology and Immunology, School of Life Science, National Yang-Ming University, Taipei, Taiwan 11221, Republic of China

Received 16 June 1999/Returned for modification 17 July 1999/Accepted 17 August 1999

Nopp140 is thought to shuttle between nucleolus and cytoplasm. However, the predominant nucleolar localization of Nopp140 homologues from different species suggests that Nopp140 is also involved in events occurring within the nucleolus. In this study, we demonstrated that the largest subunit of RNA polymerase I, RPA194, was coimmunoprecipitated with the human Nopp140 (hNopp140). Such an interaction is mediated through amino acids 204 to 382 of hNopp140. By double immunofluorescence, hNopp140 was colocalized with RNA polymerase I at the rDNA (rRNA genes) transcription active foci in the nucleolus. These results suggest that Nopp140 can interact with RNA polymerase I in vivo. Transfected cells expressing the amino-terminal half of hNopp140, hNopp140N382 (amino acids 1 to 382), displayed altered nucleoli with crescent-shaped structures. This phenotype is reminiscent of the segregated nucleoli induced by actinomycin D treatment, which is known to inhibit rRNA synthesis. Consistently, the hNopp140N382 protein mislocalized the endogenous RNA polymerase I and shut off cellular rRNA gene transcription as revealed by an in situ run-on assay. These dominant negative effects of the mutant hNopp140N382 suggest that Nopp140 plays an essential role in rDNA transcription. Interestingly, ectopic expression of hNopp140 to a very high level caused the formation of a transcriptionally inactive spherical structure occupying the entire nucleolar area which trapped the RNA polymerase I, fibrillarin, and hNopp140 but excluded the nucleolin. The mislocalizations of these nucleolar proteins after hNopp140 overexpression imply that Nopp140 may also play roles in maintenance of nucleolar integrity.

* Corresponding author. Mailing address: Institute of Microbiology and Immunology, School of Life Science, National Yang-Ming University, Taipei 11221, Taiwan. Phone: 886-2-2826-7113. Fax: 886-2-2821-2880. E-mail: yphcsl{at}ym.edu.tw.

dagger Present address: Department of Biology, The Johns Hopkins University, Baltimore, MD 21218.

Molecular and Cellular Biology, December 1999, p. 8536-8546, Vol. 19, No. 12
0270-7306/99/$04.00+0
Copyright © 1999, American Society for Microbiology. All rights reserved.


This article has been cited by other articles:

  • Prieto, J.-L., McStay, B. (2007). Recruitment of factors linking transcription and processing of pre-rRNA to NOR chromatin is UBF-dependent and occurs independent of transcription in human cells. Genes Dev. 21: 2041-2054 [Abstract] [Full Text]  
  • Cui, Z., DiMario, P. J. (2007). RNAi Knockdown of Nopp140 Induces Minute-like Phenotypes in Drosophila. Mol. Biol. Cell 18: 2179-2191 [Abstract] [Full Text]  
  • Kittur, N., Zapantis, G., Aubuchon, M., Santoro, N., Bazett-Jones, D. P., Meier, U. T. (2007). The Nucleolar Channel System of Human Endometrium Is Related to Endoplasmic Reticulum and R-Rings. Mol. Biol. Cell 18: 2296-2304 [Abstract] [Full Text]  
  • Kelly, S., Singleton, W., Wickstead, B., Ersfeld, K., Gull, K. (2006). Characterization and Differential Nuclear Localization of Nopp140 and a Novel Nopp140-Like Protein in Trypanosomes. Eukaryot Cell 5: 876-879 [Abstract] [Full Text]  
  • Gonzales, B., Henning, D., So, R. B., Dixon, J., Dixon, M. J., Valdez, B. C. (2005). The Treacher Collins syndrome (TCOF1) gene product is involved in pre-rRNA methylation. Hum Mol Genet 14: 2035-2043 [Abstract] [Full Text]  
  • Shav-Tal, Y., Blechman, J., Darzacq, X., Montagna, C., Dye, B. T., Patton, J. G., Singer, R. H., Zipori, D. (2005). Dynamic Sorting of Nuclear Components into Distinct Nucleolar Caps during Transcriptional Inhibition. Mol. Biol. Cell 16: 2395-2413 [Abstract] [Full Text]  
  • Christensen, M. O., Krokowski, R. M., Barthelmes, H. U., Hock, R., Boege, F., Mielke, C. (2004). Distinct Effects of Topoisomerase I and RNA Polymerase I Inhibitors Suggest a Dual Mechanism of Nucleolar/Nucleoplasmic Partitioning of Topoisomerase I. J. Biol. Chem. 279: 21873-21882 [Abstract] [Full Text]  
  • Chiu, C.-M., Tsay, Y.-G., Chang, C.-J., Lee, S.-C. (2002). Nopp140 Is a Mediator of the Protein Kinase A Signaling Pathway That Activates the Acute Phase Response alpha 1-Acid Glycoprotein Gene. J. Biol. Chem. 277: 39102-39111 [Abstract] [Full Text]  
  • Isaac, C., Pollard, J. W., Meier, U. T. (2001). Intranuclear endoplasmic reticulum induced by Nopp140 mimics the nucleolar channel system of human endometrium. J. Cell Sci. 114: 4253-4264 [Abstract] [Full Text]  
  • Snaar, S., Wiesmeijer, K., Jochemsen, A. G., Tanke, H. J., Dirks, R. W. (2000). Mutational Analysis of Fibrillarin and Its Mobility in Living Human Cells. JCB 151: 653-662 [Abstract] [Full Text]  
  • Isaac, C., Marsh, K. L., Paznekas, W. A., Dixon, J., Dixon, M. J., Jabs, E. W., Meier, U. T. (2000). Characterization of the Nucleolar Gene Product, Treacle, in Treacher Collins Syndrome. Mol. Biol. Cell 11: 3061-3071 [Abstract] [Full Text]  
  • Waggener, J. M., DiMario, P. J. (2002). Two Splice Variants of Nopp140 in Drosophila melanogaster. Mol. Biol. Cell 13: 362-381 [Abstract] [Full Text]  


Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»