title: Virus-mediated or transgenic suppression of a G-protein alpha subunit and attenuation of fungal virulence.
abstract: Strains of the chestnut blight fungus Cryphonectria parasitica harboring RNA viruses of the genus Hypovirus exhibit significantly reduced levels of virulence (called hypovirulence). The accumulation of a heterotrimeric GTP-binding protein (G protein) alpha subunit of the Gi class was found to be reduced in hypovirus-containing C. parasitica strains. Transgenic cosuppression, a phenomenon frequently observed in transgenic plants, reduced the accumulation of this alpha subunit in virus-free fungal strains. Significantly, the resulting transgenic fungal strains were also hypovirulent. These results indicate a crucial role for G-protein-linked signal transduction in fungal pathogenesis and suggest a molecular basis for virus-mediated attenuation of fungal virulence.
authors: Roche Institute of Molecular Biology, Roche Research Center, Nutley, NJ 07110.
authors: G H
authors: GH
authors: Choi
authors: B
authors: B
authors: Chen
authors: D L
authors: DL
authors: Nuss
mesh_terms: D000595:Amino Acid Sequence; D015153:Blotting, Western; D016384:Consensus Sequence; D004591:Electrophoresis, Polyacrylamide Gel; D005656:Fungal Proteins / Q000096:biosynthesis* / Q000302:isolation & purification; D019206:GTP-Binding Protein alpha Subunits, Gi-Go; D019204:GTP-Binding Proteins / Q000096:biosynthesis* / Q000302:isolation & purification; D005800:Genes, Fungal; D020962:Heterotrimeric GTP-Binding Proteins; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D008970:Molecular Weight; D019814:Myristic Acid; D009227:Myristic Acids / Q000378:metabolism; D030821:Plants, Genetically Modified; D012328:RNA Viruses / Q000502:physiology*; D014774:Virulence; D013098:Xylariales / Q000235:genetics / Q000472:pathogenicity* / Q000821:virology*
chemical_list: C091426:CPG-1 protein, Cryphonectria parasitica; C091427:CPG-2 protein, Cryphonectria parasitica; D005656:Fungal Proteins; D046911:Macromolecular Substances; D009227:Myristic Acids; D019814:Myristic Acid; D019204:GTP-Binding Proteins; D019206:GTP-Binding Protein alpha Subunits, Gi-Go; D020962:Heterotrimeric GTP-Binding Proteins