Cell-to-cell movement of potato virus X involves distinct functions of the coat protein

• Published in: Journal of general virology Vol. 82; no. 2; pp. 449 - 458
• Main Authors: Fedorkin, O. N, Solovyev, A. G, Yelina, N. E, Zamyatnin, A. A., Jr, Zinovkin, R. A, Makinen, K, Schiemann, J, Yu. Morozov, S
• Format: Journal Article
• Language: English
• Published: England Soc General Microbiol 01.02.2001
• Subjects: Beet yellows virus; Biological Transport; Capsid - chemistry; Capsid - genetics; Capsid - metabolism; Closterovirus; Closterovirus - chemistry; Closterovirus - genetics; Genetic Complementation Test; Movement; Mutation - genetics; Nicotiana - cytology; Nicotiana - virology; Plant Leaves - cytology; Plant Leaves - virology; Plants, Toxic; Plasmids - genetics; Potato virus X; Potexvirus - chemistry; Potexvirus - genetics; Potexvirus - physiology; Potyvirus; Sequence Homology; Tobacco mosaic virus; Tobacco Mosaic Virus - chemistry; Tobacco Mosaic Virus - genetics
• ISSN: 0022-1317; 1465-2099
• DOI: 10.1099/0022-1317-82-2-449

Department of Virology and A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, 119899, Moscow, Russia 1 Institute of Biotechnology, Program for Plant Molecular Biology, Viikki Biocentre, University of Helsinki, PO Box 56 (Viikinkaari 9), FIN-00014, Helsinki, Finland 2 Institute for Plant Virology, Microbiology and Biosafety, Federal Biological Research Centre for Agriculture and Forestry, Messeweg 11/12, D-38104 Braunschweig, Germany 3 Author for correspondence: Sergey Morozov. Fax +7 095 939 31 81. e-mail morozov{at}vir512.genebee.msu.su Complementation of movement-deficient potato virus X (PVX) coat protein (CP) mutants, namely PVX.CP-Xho lacking the 18 C-terminal amino acid residues and PVX. CP lacking the entire CP gene, was studied by transient co-expression with heterologous proteins. These data demonstrated that the potyvirus CPs and both the major and minor CPs of beet yellows closterovirus could complement cell-to-cell movement of PVX.CP-Xho but not PVX. CP. These data also indicated that the C-terminally truncated PVX CP lacked a movement function which could be provided in trans by the CPs of other filamentous viruses, whereas another movement determinant specified by some region outside the most C-terminal part of the PVX CP could not be complemented either by potyvirus or closterovirus CPs. Surprisingly, the CP of spherical cocksfoot mottle sobemovirus rescued all of the PVX CP movement functions, complementing the spread of PVX.CP-Xho and, to a lesser extent, PVX. CP. Both these mutants were also rescued by the tobacco mosaic virus (TMV) movement protein (MP). To shed light on the movement function of PVX CP, attempts were made to complement PVX.CP-Xho by a series of TMV MP mutants. An internal deletion abolished complementation, suggesting that the internal region of TMV MP, which includes a number of overlapping functional domains important for cell-to-cell transport, provides an activity complementing movement determinant(s) specified by the C-terminal region of PVX CP.