JVI Figure table search 04
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
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 Anouja, F.
Right arrow Articles by Caillet-Fauquet, P.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Anouja, F.
Right arrow Articles by Caillet-Fauquet, P.

 Previous Article  |  Next Article 

J. Virol., Jun 1997, 4671-4678, Vol 71, No. 6
Copyright © 1997, American Society for Microbiology

The cytotoxicity of the parvovirus minute virus of mice nonstructural protein NS1 is related to changes in the synthesis and phosphorylation of cell proteins

F Anouja, R Wattiez, S Mousset and P Caillet-Fauquet
Departement de Biologie Moleculaire, Universite Libre de Bruxelles, Rhode-St-Genese, Belgium.

Autonomous parvoviruses exert lytic and cytostatic effects believed to contribute to their antineoplastic activity. Studies with inducible clones have demonstrated a direct involvement of parvovirus nonstructural proteins (NS) in oncolysis. Human and rat fibroblasts have been stably transfected with MVM(p) (minute virus of mice prototype strain) NS genes cloned under the control of a hormone- inducible promoter. Dexamethasone-induced synthesis of the NS proteins in sensitive transformed cells results in cell killing within a few days. From these sensitive cell lines have been isolated some NS- resistant clones that also prove resistant to MVM(p) infection, suggesting that cell factors modulate NS cytotoxicity. We have previously reported that factors involved in cell cycle regulation may contribute to this modulation, since NS toxicity requires cell proliferation and correlates with a cell cycle perturbation leading to an arrest in phase S/G2. In addition to its role in cytotoxicity, NS1 can regulate transcription driven by parvovirus and nonparvovirus promoters. Since phosphorylation is a critical event in controlling the activity of many proteins, notably transcription factors and cell cycle- regulated proteins, we have examined the effect of NS1 on the synthesis and phosphorylation of cell proteins. Our results indicate that NS1 interferes, within 7 h of induction, with phosphorylation of a protein of about 14 kDa (p14). Cell synchronization has enabled us to show that phosphorylation of this protein occurs in early S phase and is prevented when NS1 is induced. This early effect of NS1 on p14 phosphorylation may be directly linked to cytotoxicity and is probably related to the previously reported inhibition of cell DNA synthesis. Late in the induction period (24 h), NS1 also alters the synthesis of a 50-kDa protein and a 35-kDa protein (p50 and p35, respectively). Microsequencing of p35 reveals sequence homology with beta-tubulin. These effects of NS1, observed only in NS1-sensitive cell lines, may be related to the protein's cytotoxicity.


This article has been cited by other articles:




Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
J. Bacteriol. Mol. Cell. Biol. Microbiol. Mol. Biol. Rev.
Clin. Vaccine Immunol. ALL ASM JOURNALS

Copyright © 1997 by the American Society for Microbiology. All rights reserved.