Mutational analysis of the cowpea mosaic virus movement protein.
Cowpea mosaic virus moves from cell-to-cell in a virion form through tubular structures that are assembled in modified plasmodesmata. Similar tubular structures are formed on the surface of protoplasts inoculated with cowpea mosaic virus. The RNA 2-encoded movement protein (MP) is responsible for the induction and formation of these structures. To define functional domains of the MP, an alanine-substitution mutagenesis was performed on eight positions in the MP, including two conserved sequence motifs, the LPL and D motifs. Results show that these two conserved motifs as well as the central region of the MP are essential for cell-to-cell movement. Several viruses carrying mutations in the N- or C-terminal parts of their MP retained infectivity on cowpea plants. Coexpression studies revealed that mutant MPs did not interfere with the activity of wild-type MP and could not mutually complement their defects.
Bertens
P
P
Laboratories of Molecular Biology, Virology, Graduate School for Experimental Plant Sciences, Wageningen University, Dreijenlaan 3, Wageningen, 6703 HA, The Netherlands.
Wellink
J
J
Goldbach
R
R
van Kammen
A
A
D000409:Alanine / Q000235:genetics; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D017798:Comovirus / Q000235:genetics* / Q000254:growth & development; D007887:Fabaceae / Q000821:virology; D005816:Genetic Complementation Test; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D053830:Plant Viral Movement Proteins; D010946:Plants, Medicinal; D012367:RNA, Viral / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D014764:Viral Proteins / Q000235:genetics*; D014779:Virus Replication
D053830:Plant Viral Movement Proteins; D012367:RNA, Viral; D014764:Viral Proteins; D000409:Alanine