title: Experimental and bioinformatic evidence that raspberry leaf blotch emaravirus P4 is a movement protein of the 30K superfamily.
abstract: Emaravirus is a recently described genus of negative-strand RNA plant viruses. Emaravirus P4 protein localizes to plasmodesmata, suggesting that it could be a viral movement protein (MP). In the current study, we showed that the P4 protein of raspberry leaf blotch emaravirus (RLBV) rescued the cell-to-cell movement of a defective potato virus X (PVX) that had a deletion mutation in the triple gene block 1 movement-associated protein. This demonstrated that RLBV P4 is a functional MP. Sequence analyses revealed that P4 is a distant member of the 30K superfamily of MPs. All MPs of this family contain two highly conserved regions predicted to form β-strands, namely β1 and β2. We explored by alanine mutagenesis the role of two residues of P4 (Ile106 and Asp127) located in each of these strands. We also made the equivalent substitutions in the 29K MP of tobacco rattle virus, another member of the 30K superfamily. All substitutions abolished the ability to complement PVX movement, except for the I106A substitution in the β1 region of P4. This region has been shown to mediate membrane association of 30K MPs; our results show that it is possible to make non-conservative substitutions of a well-conserved aliphatic residue within β1 without preventing the membrane association or movement function of P4.
authors.affiliation: Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, PR China.
authors.forename: Chulang
authors.initials: C
authors.lastname: Yu
authors.affiliation: Division of Structural Biology, Henry Wellcome Building, Roosevelt Drive, Oxford OX3 7BN, UK.|Department of Zoology, Oxford University, South Parks Road, Oxford OX1 3PS, UK.
authors.forename: David G
authors.initials: DG
authors.lastname: Karlin
authors.affiliation: Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, PR China.
authors.forename: Yuwen
authors.initials: Y
authors.lastname: Lu
authors.affiliation: James Hutton Institute, Cell and Molecular Sciences Group, Invergowrie, Dundee DD2 5DA, UK.
authors.forename: Kathryn
authors.initials: K
authors.lastname: Wright
authors.affiliation: Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, PR China.
authors.forename: Jianping
authors.initials: J
authors.lastname: Chen
authors.affiliation: James Hutton Institute, Cell and Molecular Sciences Group, Invergowrie, Dundee DD2 5DA, UK.
authors.forename: Stuart
authors.initials: S
authors.lastname: MacFarlane
mesh_terms: D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D019295:Computational Biology; D004252:DNA Mutational Analysis; D005816:Genetic Complementation Test; D008969:Molecular Sequence Data; D050505:Mutant Proteins / Q000235:genetics / Q000378:metabolism; D010935:Plant Diseases / Q000821:virology*; D018515:Plant Leaves / Q000821:virology; D053830:Plant Viral Movement Proteins / Q000235:genetics* / Q000378:metabolism; D010942:Plant Viruses / Q000235:genetics* / Q000302:isolation & purification; D031425:Plasmodesmata / Q000821:virology; D017863:Potexvirus / Q000235:genetics / Q000254:growth & development; D012328:RNA Viruses / Q000235:genetics* / Q000302:isolation & purification; D027824:Rosaceae / Q000821:virology*; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D014776:Virus Cultivation
chemical_list: D050505:Mutant Proteins; D053830:Plant Viral Movement Proteins