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 Spuul, P.
Right arrow Articles by Ahola, T.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Spuul, P.
Right arrow Articles by Ahola, T.

 Previous Article  |  Next Article 

Journal of Virology, January 2007, p. 872-883, Vol. 81, No. 2
0022-538X/07/$08.00+0     doi:10.1128/JVI.01785-06
Copyright © 2007, American Society for Microbiology. All Rights Reserved.

Role of the Amphipathic Peptide of Semliki Forest Virus Replicase Protein nsP1 in Membrane Association and Virus Replication{triangledown}

Pirjo Spuul,1 Anne Salonen,1 Andres Merits,3 Eija Jokitalo,2 Leevi Kääriäinen,1 and Tero Ahola1*

Program in Cellular Biotechnology,1 Electron Microscopy Unit, Institute of Biotechnology, University of Helsinki, Helsinki, Finland,2 Estonian Biocentre and Institute of Molecular and Cellular Biology, Tartu, Estonia3

Received 17 August 2006/ Accepted 26 October 2006

Semliki Forest virus RNA replication takes place in association with specific cytoplasmic vacuoles, derived from the endosomal apparatus. Of the four virus-encoded replicase proteins, nsP1 serves as the membrane anchor of the replication complex. An amphipathic peptide segment, G245STLYTESRKLLRSWHLPSV264, has been implicated in the membrane binding of nsP1. nsP1 variants with changes within the peptide were studied after protein expression and in the context of virus infection. Proteins with mutations R253E and W259A accumulated in the cytoplasm and were very poorly palmitoylated. The same mutations also drastically affected the localization of the precursor polyprotein P123, and they were lethal when introduced into the virus genome. Mutations R253A and L255A+L256A partially changed the localization of nsP1, and the respective viruses acquired compensatory changes. L255A+L256A only yielded virus encoding L255A+L256V, indicating the importance of a hydrophobic residue in the central 256 position. When fused to green fluorescent protein, the peptide was required in at least two tandem copies to effect a change in localization, but even then the fusion protein was associated with membranes in a nonspecific manner. Thus, the amphipathic peptide is a crucial element for the membrane association of nsP1 and the replication complex. It provides essential affinity for membranes, and other regions of nsP1 also appear to contribute to the localization of the protein.

* Corresponding author. Mailing address: Institute of Biotechnology, P.O. Box 56 (Viikinkaari 9), University of Helsinki, 00014 Helsinki, Finland. Phone: 358-9-19159403. Fax: 358-9-19159560. E-mail: tero.ahola{at}helsinki.fi.

{triangledown} Published ahead of print on 8 November 2006.

Journal of Virology, January 2007, p. 872-883, Vol. 81, No. 2
0022-538X/07/$08.00+0     doi:10.1128/JVI.01785-06
Copyright © 2007, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Stapleford, K. A., Rapaport, D., Miller, D. J. (2009). Mitochondrion-Enriched Anionic Phospholipids Facilitate Flock House Virus RNA Polymerase Membrane Association. J. Virol. 83: 4498-4507 [Abstract] [Full Text]  
  • Lulla, V., Sawicki, D. L., Sawicki, S. G., Lulla, A., Merits, A., Ahola, T. (2008). Molecular Defects Caused by Temperature-Sensitive Mutations in Semliki Forest Virus nsP1. J. Virol. 82: 9236-9244 [Abstract] [Full Text]  
  • Kiiver, K., Tagen, I., Zusinaite, E., Tamberg, N., Fazakerley, J. K., Merits, A. (2008). Properties of non-structural protein 1 of Semliki Forest virus and its interference with virus replication. J. Gen. Virol. 89: 1457-1466 [Abstract] [Full Text]  
  • Zusinaite, E., Tints, K., Kiiver, K., Spuul, P., Karo-Astover, L., Merits, A., Sarand, I. (2007). Mutations at the palmitoylation site of non-structural protein nsP1 of Semliki Forest virus attenuate virus replication and cause accumulation of compensatory mutations. J. Gen. Virol. 88: 1977-1985 [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»