title: Geminivirus pathogenicity protein C4 interacts with Arabidopsis thaliana shaggy-related protein kinase AtSKeta, a component of the brassinosteroid signalling pathway.
abstract: Beet curly top virus (BCTV) C4 interacted with two members of the shaggy-related protein kinase family (AtSKeta and AtSKzeta) and a putative leucine-rich repeat receptor-like kinase (LRR-RLK) in a yeast two-hybrid assay. Tomato golden mosaic virus (TGMV) AC4 also bound with similar efficiency to AtSKeta and AtSKzeta but was unable to interact with the LRR-RLK. BCTV C4 interaction with AtSKeta was confirmed using an in vitro binding assay. The protein kinases were capable of autophosphorylation in vitro and AtSKeta phosphorylated BCTV C4 at threonine and serine residues. AtSKeta phosphorylation of TGMV AC4 was significantly less efficient. The LRR-RLK did not efficiently phosphorylate BCTV C4. BCTV C4 localisation to the cell periphery in Nicotiana benthamiana was dependent on an intact N-terminal myristoylation motif, consistent with plasma membrane targeting. The intact motif was also required to produce the wild-type disease phenotype. Transient expression of BCTV C4 and TGMV AC4 derivatives in N. benthamiana identified additional amino acids within a central domain that contribute to the phenotype. The interaction with AtSKeta indicates that BCTV C4 interacts with the brassinosteroid signalling pathway.
authors.affiliation: Department of Disease and Stress Biology, John Innes Centre, Norwich Research Park, Colney, Norwich NR4 7UH, UK.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Piroux
authors.forename: Keith
authors.initials: K
authors.lastname: Saunders
authors.forename: Anthony
authors.initials: A
authors.lastname: Page
authors.forename: John
authors.initials: J
authors.lastname: Stanley
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000201:enzymology / Q000821:virology*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D002462:Cell Membrane / Q000737:chemistry; D018076:DNA, Complementary; D017791:Geminiviridae / Q000472:pathogenicity* / Q000502:physiology*; D015723:Gene Library; D008969:Molecular Sequence Data; D010766:Phosphorylation; D010935:Plant Diseases / Q000821:virology; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D021381:Protein Transport / Q000235:genetics; D020794:Receptor Protein-Tyrosine Kinases / Q000378:metabolism; D015398:Signal Transduction; D020798:Two-Hybrid System Techniques; D014764:Viral Proteins / Q000737:chemistry / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D018076:DNA, Complementary; D014764:Viral Proteins; D020794:Receptor Protein-Tyrosine Kinases; D017346:Protein Serine-Threonine Kinases; C521055:shaggy-related protein kinase eta, Arabidopsis