title: Mutations within A 35 amino acid region of P6 influence self-association, inclusion body formation, and Caulimovirus infectivity.
abstract: Cauliflower mosaic virus gene VI product (P6) is an essential protein that forms cytoplasmic, inclusion bodies (IBs). P6 contains four regions involved in self-association, termed D1-D4. D3 binds to D1, along with D4 and contains a spacer region (termed D3b) between two RNA-binding domains. Here we show D3b binds full-length P6 along with D1 and D4. Full-length P6s harboring single amino acid substitutions within D3b showed reduced binding to both D1 and D4. Full-length P6s containing D3b mutations and fused with green fluorescent protein formed inclusion-like bodies (IL-Bs) when expressed in Nicotiana benthamiana leaves. However, mutant P6s with reduced binding to D1 and D4, showed smaller IL-Bs, than wild type. Likewise, viruses containing these mutations showed a decrease in inoculated leaf viral DNA levels and reduced efficiency of systemic infection. These data suggest that mutations influencing P6 self-association alter IB formation and reduce virus infection.
authors.affiliation: Department of Biological Sciences, The University of Toledo, 2801 West Bancroft Street, Toledo, OH 43606, USA.
authors.forename: Lindy
authors.initials: L
authors.lastname: Lutz
authors.affiliation: Department of Biological Sciences, The University of Toledo, 2801 West Bancroft Street, Toledo, OH 43606, USA.
authors.forename: Genevieve
authors.initials: G
authors.lastname: Okenka
authors.affiliation: Division of Plant Sciences, University of Missouri, Columbia, MO 65211, USA.
authors.forename: James
authors.initials: J
authors.lastname: Schoelz
authors.affiliation: Department of Biological Sciences, The University of Toledo, 2801 West Bancroft Street, Toledo, OH 43606, USA. Electronic address: sleisne@utnet.utoledo.edu.
authors.forename: Scott
authors.initials: S
authors.lastname: Leisner
mesh_terms: D017796:Caulimovirus / Q000737:chemistry / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity; D007181:Inclusion Bodies, Viral / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D010935:Plant Diseases / Q000821:virology*; D017434:Protein Structure, Tertiary; D014026:Nicotiana / Q000821:virology*; D015534:Trans-Activators / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D014774:Virulence
chemical_list: D015534:Trans-Activators; C095687:gene VI protein, Cauliflower mosaic virus
keywords: CaMV; Gene VI product; Inclusion bodies; TAV