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
Google Scholar
Right arrow Articles by Romanova, L. I.
Right arrow Articles by Agol, V. I.
PubMed
Right arrow PubMed Citation
Right arrow Articles by Romanova, L. I.
Right arrow Articles by Agol, V. I.

 Previous Article  |  Next Article 

Journal of Virology, July 2009, p. 7273-7284, Vol. 83, No. 14
0022-538X/09/$08.00+0     doi:10.1128/JVI.00467-09
Copyright © 2009, American Society for Microbiology. All Rights Reserved.

Antiapoptotic Activity of the Cardiovirus Leader Protein, a Viral "Security" Protein{triangledown}

Lyudmila I. Romanova,1,{dagger} Peter V. Lidsky,1,{dagger} Marina S. Kolesnikova,1 Ksenia V. Fominykh,1,2 Anatoly P. Gmyl,1 Eugene V. Sheval,2 Stanleyson V. Hato,3 Frank J. M. van Kuppeveld,3 and Vadim I. Agol1,2*

M. P. Chumakov Institute of Poliomyelitis and Viral Encephalitides, Russian Academy of Medical Sciences, Moscow 142782, Russia,1 M. V. Lomonosov Moscow State University, Moscow 119899, Russia,2 Department of Medical Microbiology, Radboud University Nijmegen Medical Centre, Nijmegen Centre for Molecular Life Sciences, Nijmegen 6500 HB, The Netherlands3

Received 5 March 2009/ Accepted 29 April 2009

Apoptosis is a common antiviral defensive mechanism that potentially limits viral reproduction and spread. Many viruses possess apoptosis-suppressing tools. Here, we show that the productive infection of HeLa cells with encephalomyocarditis virus (a cardiovirus) was not accompanied by full-fledged apoptosis (although the activation of caspases was detected late in infection) but rather elicited a strong antiapoptotic state, as evidenced by the resistance of infected cells to viral and nonviral apoptosis inducers. The development of the antiapoptotic state appeared to depend on a function(s) of the viral leader (L) protein, since its mutational inactivation resulted in the efflux of cytochrome c from mitochondria, the early activation of caspases, and the appearance of morphological and biochemical signs of apoptosis in a significant proportion of infected cells. Infection with both wild-type and L-deficient viruses induced the fragmentation of mitochondria, which in the former case was not accompanied with cytochrome c efflux. Although the exact nature of the antiapoptotic function(s) of cardioviruses remains obscure, our results suggested that it includes previously undescribed mechanisms operating upstream and possibly downstream of the mitochondrial level, and that L is involved in the control of these mechanisms. We propose that cardiovirus L belongs to a class of viral proteins, dubbed here security proteins, whose roles consist solely, or largely, in counteracting host antidefenses. Unrelated L proteins of other picornaviruses as well as their highly variable 2A proteins also may be security proteins. These proteins appear to be independent acquisitions in the evolution of picornaviruses, implying multiple cases of functional (though not structural) convergence.


* Corresponding author. Mailing address: Institute of Poliomyelitis, Moscow Region 142782, Russia. Phone: 7 (495) 439 9026. Fax: 7 (495) 439 9321. E-mail: agol{at}belozersky.msu.ru

{triangledown} Published ahead of print on 6 May 2009.

{dagger} L.I.R. and P.V.L. contributed equally to this study.


Journal of Virology, July 2009, p. 7273-7284, Vol. 83, No. 14
0022-538X/09/$08.00+0     doi:10.1128/JVI.00467-09
Copyright © 2009, American Society for Microbiology. All Rights Reserved.




This article has been cited by other articles:

  • Lidsky, P. V., Romanova, L. I., Kolesnikova, M. S., Bardina, M. V., Khitrina, E. V., Hato, S. V., van Kuppeveld, F. J. M., Agol, V. I. (2009). Interactions between Viral and Prokaryotic Pathogens in a Mixed Infection with Cardiovirus and Mycoplasma. J. Virol. 83: 9940-9951 [Abstract] [Full Text]