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

This Article Full Text Full Text (PDF) Supplementary Table 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 CrossRef Citing Articles via Google Scholar Google Scholar Articles by Kimalov, B. Articles by Arazi, T. Search for Related Content PubMed PubMed Citation Articles by Kimalov, B. Articles by Arazi, T. Agricola Articles by Kimalov, B. Articles by Arazi, T.

Maintenance of coat protein N-terminal net charge and not primary sequence is essential for zucchini yellow mosaic virus systemic infectivity

¹ Department of Ornamental Horticulture, Agricultural Research Organization, The Volcani Center, PO Box 6, Bet Dagan 50250, Israel
² Department of Virology, Agricultural Research Organization, The Volcani Center, PO Box 6, Bet Dagan 50250, Israel
³ Horticulture Institute, Agricultural Research Organization, The Volcani Center, PO Box 6, Bet Dagan 50250, Israel

Correspondence
Tzahi Arazi
tarazi{at}volcani.agri.gov.il

Zucchini yellow mosaic virus (ZYMV) surface exposed coat protein (CP) N-terminal domain (Nt) is 43 aa long and contains an equal number of positively and negatively charged amino acid residues (CP-Nt net charge=0). A ZYMV-AGII truncation mutant lacking the first 20 aa of its CP-Nt (AGII-CP20; CP-Nt net charge=+2) was found to be systemically non-infectious even though AGII mutants harbouring larger CP-Nt deletions were previously demonstrated to be fully infectious. Nevertheless, AGII-CP20 infectivity was restored by fusion to its CP-Nt two Asp residues or a negatively charged Myc peptide, both predicted to neutralize CP-Nt net positive charge. To evaluate further the significance of CP-Nt net charge for AGII infectivity, a series of CP-Nt net charge mutants was generated and analysed for systemic infectivity of squash plants. AGII-CP^KKK harbouring a CP-Nt amino fusion of three Lys residues (CP-Nt net charge=+3) was not systemically infectious. Addition of up to four Asp residues to CP-Nt did not abolish virus infectivity, although certain mutants were genetically unstable and had delayed infectivity. Addition of five negatively charged residues abolished infectivity (AGII-CP^DDDDD; CP-Nt net charge=–5) even though a recombinant CP^DDDDD could assemble into potyviral-like particle in bacteria. Neutralization of CP-Nt net charge by fusing Asp or Lys residues recovered infectivity of AGII-CP^KKK and AGII-CP^DDDDD. GFP-tagging of these mutants has demonstrated that both viruses have defective cell-to-cell movement. Together, these findings suggest that maintenance of CP-Nt net charge and not primary sequence is essential for ZYMV infectivity.

Supplementary table presenting CP-Nt net charge of various potyviruses is available in JGV Online.

This article has been cited by other articles:

				Y. M. Shiboleth, E. Haronsky, D. Leibman, T. Arazi, M. Wassenegger, S. A. Whitham, V. Gaba, and A. Gal-On The Conserved FRNK Box in HC-Pro, a Plant Viral Suppressor of Gene Silencing, Is Required for Small RNA Binding and Mediates Symptom Development J. Virol., December 1, 2007; 81(23): 13135 - 13148. [Abstract] [Full Text] [PDF]

				C. Lico, F. Capuano, G. Renzone, M. Donini, C. Marusic, A. Scaloni, E. Benvenuto, and S. Baschieri Peptide display on Potato virus X: molecular features of the coat protein-fused peptide affecting cell-to-cell and phloem movement of chimeric virus particles. J. Gen. Virol., October 1, 2006; 87(Pt 10): 3103 - 3112. [Abstract] [Full Text] [PDF]

				J. R. Thompson, S. Doun, and K. L. Perry Compensatory Capsid Protein Mutations in Cucumber Mosaic Virus Confer Systemic Infectivity in Squash (Cucurbita pepo). J. Virol., August 1, 2006; 80(15): 7740 - 7743. [Abstract] [Full Text] [PDF]