Previous Article | Next Article ![]()
Journal of Virology, July 1999, p. 5613-5620, Vol. 73, No. 7
Department of Microbiology and Immunology,
University of Miami School of Medicine, Miami, Florida
33136,1 and Department of Virology, The
Cleveland Clinic Foundation, Cleveland, Ohio
441952
Received 3 September 1998/Accepted 29 March 1999
The phosphoprotein, P, of vesicular stomatitis virus (VSV) is a key
subunit of the viral RNA-dependent RNA polymerase complex. The protein
is phosphorylated at multiple sites in two different domains. We
recently showed that specific serine and threonine residues within the
amino-terminal acidic domain I of P protein must be phosphorylated for
in vivo transcription activity, but not for replication activity, of
the polymerase complex. To examine the role of phosphorylation of the
carboxy-terminal domain II residues of the P protein in transcription
and replication, we have used a panel of mutant P proteins in which the
phosphate acceptor sites (Ser-226, Ser-227, and Ser-233) were altered
to alanines either individually or in various combinations. Analyses of
the mutant proteins for their ability to support replication of a VSV
minigenomic RNA suggest that phosphorylation of either Ser-226 or
Ser-227 is necessary for optimal replication activity of the protein.
The mutant protein (P226/227) in which both of these
residues were altered to alanines was only about 8% active in
replication compared to the wild-type (wt) protein. Substitution of
alanine for Ser-233 did not have any adverse effect on replication activity of the protein. In contrast, all the mutant proteins showed
activities similar to that of the wt protein in transcription. These
results indicate that phosphorylation of the carboxy-terminal domain II
residues of P protein are required for optimal replication activity but
not for transcription activity. Furthermore, substitution of glutamic
acid residues for Ser-226 and Ser-227 resulted in a protein that was
only 14% active in replication but almost fully active in
transcription. Taken together, these results, along with our earlier
studies, suggest that phosphorylation of residues at two different
domains in the P protein regulates its activity in transcription and
replication of the VSV genome.
0022-538X/99/$04.00+0
Copyright © 1999, American Society for Microbiology. All rights reserved.
Optimal Replication Activity of Vesicular
Stomatitis Virus RNA Polymerase Requires Phosphorylation of a
Residue(s) at Carboxy-Terminal Domain II of Its Accessory Subunit,
Phosphoprotein P
*
Corresponding author. Mailing address: Department of
Microbiology and Immunology, University of Miami School of Medicine, P.O. Box 016960 (R-138), Miami, FL 33101. Phone: (305) 243-6711. Fax:
(305) 243-4623. E-mail:
apattnaik{at}mednet.med.miami.edu.
This article has been cited by other articles:
| J. Bacteriol. | Mol. Cell. Biol. | Microbiol. Mol. Biol. Rev. |
|---|
| Clin. Vaccine Immunol. | ALL ASM JOURNALS |
|---|