HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

J. Biol. Chem., Vol. 276, Issue 8, 5745-5752, February 23, 2001

This Article Full Text Full Text (PDF) All Versions of this Article: 276/8/5745    most recent M006077200v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Vihinen, H. Articles by Kääriäinen, L. Search for Related Content PubMed PubMed Citation Articles by Vihinen, H. Articles by Kääriäinen, L. Social Bookmarking                      What's this?

Elimination of Phosphorylation Sites of Semliki Forest Virus Replicase Protein nsP3^*

Helena Vihinen^§, Tero Ahola^¶, Minna Tuittila, Andres Merits, and Leevi Kääriäinen^**

From the  Program in Cellular Biotechnology, Institute of Biotechnology, Viikki Biocenter, P.O. Box 56, University of Helsinki, FIN-00014 Helsinki, and the  Department of Biochemistry and Pharmacy, Åbo Academi and University, FIN-20520 Turku, Finland

nsP3 is one of the four RNA replicase subunits encoded by alphaviruses. The specific essential functions of nsP3 remain unknown, but it is known to be phosphorylated on serine and threonine residues. Here we have completed mapping of the individual phosphorylation sites on Semliki Forest virus nsP3 (482 amino acids) by point mutational analysis of threonine residues. This showed that threonines 344 and 345 represented the major threonine phosphorylation sites in nsP3. Experiments with deletion variants suggested that nsP3 itself had no kinase activity; instead, it was likely to be phosphorylated by multiple cellular kinases. Phosphorylation was not necessary for the peripheral membrane association of nsP3, which was mediated by the N-terminal region preceding the phosphorylation sites. Two deletion variants of nsP3 with either reduced or undetectable phosphorylation were studied in the context of virus infection. Cells infected with mutant viruses produced close to wild type levels of infectious virions; however, the rate of viral RNA synthesis was significantly reduced in the mutants. A virus totally defective in nsP3 phosphorylation and exhibiting a decreased rate of RNA synthesis also exhibited greatly reduced pathogenicity in mice.

CiteULike

Complore

Connotea

Del.icio.us

Digg

Reddit

Technorati

This article has been cited by other articles:

				G. Balistreri, J. Caldentey, L. Kaariainen, and T. Ahola Enzymatic Defects of the nsP2 Proteins of Semliki Forest Virus Temperature-Sensitive Mutants J. Virol., March 15, 2007; 81(6): 2849 - 2860. [Abstract] [Full Text] [PDF]

				K. M. Myles, C. L. H. Kelly, J. P. Ledermann, and A. M. Powers Effects of an Opal Termination Codon Preceding the nsP4 Gene Sequence in the O'Nyong-Nyong Virus Genome on Anopheles gambiae Infectivity. J. Virol., May 1, 2006; 80(10): 4992 - 4997. [Abstract] [Full Text] [PDF]

				S. E. Galbraith, B. J. Sheahan, and G. J. Atkins Deletions in the hypervariable domain of the nsP3 gene attenuate Semliki Forest virus virulence. J. Gen. Virol., April 1, 2006; 87(Pt 4): 937 - 947. [Abstract] [Full Text] [PDF]

				I. De, C. Fata-Hartley, S. G. Sawicki, and D. L. Sawicki Functional Analysis of nsP3 Phosphoprotein Mutants of Sindbis Virus J. Virol., December 15, 2003; 77(24): 13106 - 13116. [Abstract] [Full Text] [PDF]

				M. Tuittila and A. E. Hinkkanen Amino acid mutations in the replicase protein nsP3 of Semliki Forest virus cumulatively affect neurovirulence J. Gen. Virol., June 1, 2003; 84(6): 1525 - 1533. [Abstract] [Full Text] [PDF]

				A. Salonen, L. Vasiljeva, A. Merits, J. Magden, E. Jokitalo, and L. Kaariainen Properly Folded Nonstructural Polyprotein Directs the Semliki Forest Virus Replication Complex to the Endosomal Compartment J. Virol., February 1, 2003; 77(3): 1691 - 1702. [Abstract] [Full Text] [PDF]

				Y. Nishino, D. Kobasa, S. A. Rubin, M. V. Pletnikov, and K. M. Carbone Enhanced Neurovirulence of Borna Disease Virus Variants Associated with Nucleotide Changes in the Glycoprotein and L Polymerase Genes J. Virol., July 29, 2002; 76(17): 8650 - 8658. [Abstract] [Full Text] [PDF]

				J. K. Fazakerley, A. Boyd, M. L. Mikkola, and L. Kaariainen A Single Amino Acid Change in the Nuclear Localization Sequence of the nsP2 Protein Affects the Neurovirulence of Semliki Forest Virus J. Virol., January 1, 2002; 76(1): 392 - 396. [Abstract] [Full Text] [PDF]