title: Several components of SKP1/Cullin/F-box E3 ubiquitin ligase complex and associated factors play a role in Agrobacterium-mediated plant transformation.
abstract: • Successful genetic transformation of plants by Agrobacterium tumefaciens requires the import of bacterial T-DNA and virulence proteins into the plant cell that eventually form a complex (T-complex). The essential components of the T-complex include the single stranded T-DNA, bacterial virulence proteins (VirD2, VirE2, VirE3 and VirF) and associated host proteins that facilitate the transfer and integration of T-DNA. The removal of the proteins from the T-complex is likely achieved by targeted proteolysis mediated by VirF and the plant ubiquitin proteasome complex. • We evaluated the involvement of the host SKP1/culin/F-box (SCF)-E3 ligase complex and its role in plant transformation. Gene silencing, mutant screening and gene expression studies suggested that the Arabidopsis homologs of yeast SKP1 (suppressor of kinetochore protein 1) protein, ASK1 and ASK2, are required for Agrobacterium-mediated plant transformation. • We identified the role for SGT1b (suppressor of the G2 allele of SKP1), an accessory protein that associates with SCF-complex, in plant transformation. We also report the differential expression of many genes that encode F-box motif containing SKP1-interacting proteins (SKIP) upon Agrobacterium infection. • We speculate that these SKIP genes could encode the plant specific F-box proteins that target the T-complex associated proteins for polyubiquitination and subsequent degradation by the 26S proteasome.
authors.affiliation: Plant Biology Division, The Samuel Roberts Noble Foundation, Ardmore, OK 73402, USA.
authors.forename: Ajith
authors.initials: A
authors.lastname: Anand
authors.forename: Clemencia M
authors.initials: CM
authors.lastname: Rojas
authors.forename: Yuhong
authors.initials: Y
authors.lastname: Tang
authors.forename: Kirankumar S
authors.initials: KS
authors.lastname: Mysore
mesh_terms: D060054:Agrobacterium / Q000235:genetics*; D017360:Arabidopsis / Q000235:genetics* / Q000382:microbiology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D004269:DNA, Bacterial; D018506:Gene Expression Regulation, Plant; D009154:Mutation; D018515:Plant Leaves / Q000235:genetics / Q000382:microbiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D044786:S-Phase Kinase-Associated Proteins / Q000235:genetics / Q000378:metabolism; D044843:SKP Cullin F-Box Protein Ligases / Q000235:genetics / Q000378:metabolism*; D014026:Nicotiana / Q000235:genetics* / Q000382:microbiology; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014169:Transformation, Bacterial / Q000235:genetics*
chemical_list: C120363:ASK1 protein, Arabidopsis; D029681:Arabidopsis Proteins; D018797:Cell Cycle Proteins; D004269:DNA, Bacterial; D010940:Plant Proteins; D044786:S-Phase Kinase-Associated Proteins; C452191:SGT1a protein, Arabidopsis; C452192:SGT1b protein, Arabidopsis; C549998:SKIP protein, Arabidopsis; C036483:T-DNA; D014157:Transcription Factors; C484058:ASK2 protein, Arabidopsis; D044843:SKP Cullin F-Box Protein Ligases