title: Proteomic identification of potential target proteins regulated by an ASK1-mediated proteolysis pathway.
abstract: The ASK1 (ARABIDOPSIS SKP1-LIKE) protein is a critical component of the SCF (Skp1-Cullin-F box protein) ubiquitin ligase complexes that recruit target proteins for degradation by the 26S proteosome. To investigate proteins that are affected by the ASK1-mediated proteolysis pathway in Arabidopsis flowers, we compared the proteomes of the Arabidopsis wild type and ask1 mutant flower buds using two-dimensional electrophoresis (2-DE). Ten protein spots with higher or lower abundance in the ask1 mutant flowers compared to wild type flowers were excised and subjected to further mass spectrometry (MS) analysis. The results showed that they were proteins involved in photomorphogenesis, circadian oscillation, post-translation process, stress-responses and cell expansion or elongation, suggesting that those processes were affected in the ask1 mutant. The transcript levels of these genes were also compared based on the Affymetrix gene chip microarray data. No significant difference was observed for most of the genes, suggesting that the proteins with elevated levels of accumulation in the ask1 mutant could be candidate targets regulated by an ASK1-mediated proteolysis pathway. These results help to elucidate the pleiotropic functions of ASK1 in Arabidopsis developmental processes and also demonstrate the importance and necessity of studying protein levels with respect to gene functions.
authors.affiliation: 1State Key Laboratory of Genetic Engineering, Department of Biochemistry and Molecular Biology, School of Life Sciences, Fudan University, Shanghai, 200433, China.
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Wang
authors.forename: Weimin
authors.initials: W
authors.lastname: Ni
authors.forename: Xiaochun
authors.initials: X
authors.lastname: Ge
authors.forename: Jiejin
authors.initials: J
authors.lastname: Zhang
authors.forename: Hong
authors.initials: H
authors.lastname: Ma
authors.forename: Kaiming
authors.initials: K
authors.lastname: Cao
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000032:analysis* / Q000235:genetics / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D002940:Circadian Rhythm / Q000235:genetics; D015180:Electrophoresis, Gel, Two-Dimensional / Q000379:methods; D035264:Flowers / Q000235:genetics / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis; D010834:Phytochrome / Q000378:metabolism; D046988:Proteasome Endopeptidase Complex / Q000235:genetics / Q000378:metabolism; D020543:Proteome / Q000032:analysis* / Q000235:genetics; D044843:SKP Cullin F-Box Protein Ligases / Q000235:genetics / Q000378:metabolism; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods
chemical_list: C120363:ASK1 protein, Arabidopsis; D029681:Arabidopsis Proteins; D018797:Cell Cycle Proteins; D020543:Proteome; D010834:Phytochrome; D044843:SKP Cullin F-Box Protein Ligases; D046988:Proteasome Endopeptidase Complex; C061553:ATP dependent 26S protease