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 Surjit, M.
Right arrow Articles by Lal, S. K.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Surjit, M.
Right arrow Articles by Lal, S. K.

 Previous Article  |  Next Article 

Journal of Virology, September 2005, p. 11476-11486, Vol. 79, No. 17
0022-538X/05/$08.00+0     doi:10.1128/JVI.79.17.11476-11486.2005
Copyright © 2005, American Society for Microbiology. All Rights Reserved.

The Severe Acute Respiratory Syndrome Coronavirus Nucleocapsid Protein Is Phosphorylated and Localizes in the Cytoplasm by 14-3-3-Mediated Translocation

Milan Surjit,1 Ravinder Kumar,1 Rabi N. Mishra,2 Malireddy K. Reddy,2 Vincent T. K. Chow,3 and Sunil K. Lal1*

Virology Group,1 Plant Molecular Biology Group, International Centre for Genetic Engineering & Biotechnology, Aruna Asaf Ali Road, New Delhi 110067, India,2 Human Genome Laboratory, Microbiology Department, Faculty of Medicine, National University of Singapore, Kent Ridge, Singapore 1175973

Received 14 December 2004/ Accepted 19 May 2005

The severe acute respiratory syndrome coronavirus(SARS-CoV) nucleocapsid (N) protein is one of the four structural proteins of the virus and is predicted to be a 46-kDa phosphoprotein. Our in silico analysis predicted N to be heavily phosphorylated at multiple residues. Experimentally, we have shown in this report that the N protein of the SARS-CoV gets serine-phosphorylated by multiple kinases, in both the cytoplasm and the nucleus. The phosphoprotein is stable and localizes in the cytoplasm and coprecipitates with the membrane fraction. Also, using specific inhibitors of phosphorylation and an in vitro phosphorylation assay, we show that the nucleocapsid protein is a substrate of cyclin-dependent kinase (CDK), glycogen synthase kinase, mitogen-activated protein kinase, and casein kinase II. Further, we show that the phosphorylated protein is translocated to the cytoplasm by binding to 14-3-3 (tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein). 14-3-3 proteins are a family of highly conserved, ubiquitously expressed eukaryotic proteins that function primarily as adapters that modulate interactions between components of various cellular signaling and cell cycle regulatory pathways through phosphorylation-dependent protein-protein interactions. Coincidentally, the N protein was also found to downregulate the expression of the theta isoform of 14-3-3 (14-3-3{theta}), leading to the accumulation of phosphorylated N protein in the nucleus, in the absence of growth factors. Using short interfering RNA specific to 14-3-3{theta} we have inhibited its expression to show accumulation of phosphorylated N protein in the nucleus. Thus, the data presented here provide a possible mechanism for phosphorylation-dependent nucleocytoplasmic shuttling of the N protein. This 14-3-3-mediated transport of the phosphorylated N protein and its possible implications in interfering with the cellular machinery are discussed.

* Corresponding author. Mailing address: Virology Group, International Centre for Genetic Engineering & Biotechnology, P.O. Box 10504, Aruna Asaf Ali Road, New Delhi 110067, India. Phone: 91-11-26177357. Fax: 91-11-26162316. E-mail: sunillal{at}icgeb.res.in.

Journal of Virology, September 2005, p. 11476-11486, Vol. 79, No. 17
0022-538X/05/$08.00+0     doi:10.1128/JVI.79.17.11476-11486.2005
Copyright © 2005, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Chang, C.-K., Hsu, Y.-L., Chang, Y.-H., Chao, F.-A., Wu, M.-C., Huang, Y.-S., Hu, C.-K., Huang, T.-H. (2009). Multiple Nucleic Acid Binding Sites and Intrinsic Disorder of Severe Acute Respiratory Syndrome Coronavirus Nucleocapsid Protein: Implications for Ribonucleocapsid Protein Packaging. J. Virol. 83: 2255-2264 [Abstract] [Full Text]  
  • Wu, C.-H., Yeh, S.-H., Tsay, Y.-G., Shieh, Y.-H., Kao, C.-L., Chen, Y.-S., Wang, S.-H., Kuo, T.-J., Chen, D.-S., Chen, P.-J. (2009). Glycogen Synthase Kinase-3 Regulates the Phosphorylation of Severe Acute Respiratory Syndrome Coronavirus Nucleocapsid Protein and Viral Replication. J. Biol. Chem. 284: 5229-5239 [Abstract] [Full Text]  
  • Neuman, B. W., Joseph, J. S., Saikatendu, K. S., Serrano, P., Chatterjee, A., Johnson, M. A., Liao, L., Klaus, J. P., Yates, J. R. III, Wuthrich, K., Stevens, R. C., Buchmeier, M. J., Kuhn, P. (2008). Proteomics Analysis Unravels the Functional Repertoire of Coronavirus Nonstructural Protein 3. J. Virol. 82: 5279-5294 [Abstract] [Full Text]  
  • Poncelet, L., Coppens, A., Peeters, D., Bianchi, E., Grant, C. K., Kadhim, H. (2008). Detection of Antigenic Heterogeneity in Feline Coronavirus Nucleocapsid in Feline Pyogranulomatous Meningoencephalitis. Vet Pathol 45: 140-153 [Abstract] [Full Text]  
  • Reed, M. L., Howell, G., Harrison, S. M., Spencer, K.-A., Hiscox, J. A. (2007). Characterization of the Nuclear Export Signal in the Coronavirus Infectious Bronchitis Virus Nucleocapsid Protein. J. Virol. 81: 4298-4304 [Abstract] [Full Text]  
  • Saikatendu, K. S., Joseph, J. S., Subramanian, V., Neuman, B. W., Buchmeier, M. J., Stevens, R. C., Kuhn, P. (2007). Ribonucleocapsid Formation of Severe Acute Respiratory Syndrome Coronavirus through Molecular Action of the N-Terminal Domain of N Protein. J. Virol. 81: 3913-3921 [Abstract] [Full Text]  
  • Surjit, M., Jameel, S., Lal, S. K. (2007). Cytoplasmic Localization of the ORF2 Protein of Hepatitis E Virus Is Dependent on Its Ability To Undergo Retrotranslocation from the Endoplasmic Reticulum. J. Virol. 81: 3339-3345 [Abstract] [Full Text]  
  • Leung, D. T. M., van Maren, W. W. C., Chan, F. K. L., Chan, W. S., Lo, A. W. I., Ma, C. H., Tam, F. C. H., To, K. F., Chan, P. K. S., Sung, J. J. Y., Lim, P. L. (2006). Extremely Low Exposure of a Community to Severe Acute Respiratory Syndrome Coronavirus: False Seropositivity due to Use of Bacterially Derived Antigens.. J. Virol. 80: 8920-8928 [Abstract] [Full Text]  
  • Surjit, M., Liu, B., Chow, V. T. K., Lal, S. K. (2006). The Nucleocapsid Protein of Severe Acute Respiratory Syndrome-Coronavirus Inhibits the Activity of Cyclin-Cyclin-dependent Kinase Complex and Blocks S Phase Progression in Mammalian Cells. J. Biol. Chem. 281: 10669-10681 [Abstract] [Full Text]  
  • Frolova, E., Gorchakov, R., Garmashova, N., Atasheva, S., Vergara, L. A., Frolov, I. (2006). Formation of nsP3-Specific Protein Complexes during Sindbis Virus Replication.. J. Virol. 80: 4122-4134 [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»