title: Integrative network analysis of the signaling cascades in seedling leaves of bread wheat by large-scale phosphoproteomic profiling.
abstract: Here, we conducted the first large-scale leaf phosphoproteome analysis of two bread wheat cultivars by liquid chromatography-tandem mass spectrometry. Altogether, 1802 unambiguous phosphorylation sites representing 1175 phosphoproteins implicated in various molecular functions and cellular processes were identified by gene ontology enrichment analysis. Among the 1175 phosphoproteins, 141 contained 3-10 phosphorylation sites. The phosphorylation sites were located more frequently in the N- and C-terminal regions than in internal regions, and ∼70% were located outside the conserved regions. Conservation analysis showed that 90.5% of the phosphoproteins had phosphorylated orthologs in other plant species. Eighteen significantly enriched phosphorylation motifs, of which six were new wheat phosphorylation motifs, were identified. In particular, 52 phosphorylated transcription factors (TFs), 85 protein kinases (PKs), and 16 protein phosphatases (PPs) were classified and analyzed in depth. All the Tyr phosphorylation sites were in PKs such as mitogen-activated PKs (MAPKs) and SHAGGY-like kinases. A complicated cross-talk phosphorylation regulatory network based on PKs such as Snf1-related kinases (SnRKs), calcium-dependent PKs (CDPKs), and glycogen synthase kinase 3 (GSK3) and PPs including PP2C, PP2A, and BRI1 suppressor 1 (BSU1)-like protein (BSL) was constructed and was found to be potentially involved in rapid leaf growth. Our results provide a series of phosphoproteins and phosphorylation sites in addition to a potential network of phosphorylation signaling cascades in wheat seedling leaves.
authors.affiliation: College of Life Science, Capital Normal University , 100048 Beijing, China.
authors.forename: Dong-Wen
authors.initials: DW
authors.lastname: Lv
authors.forename: Pei
authors.initials: P
authors.lastname: Ge
authors.forename: Ming
authors.initials: M
authors.lastname: Zhang
authors.forename: Zhi-Wei
authors.initials: ZW
authors.lastname: Cheng
authors.forename: Xiao-Hui
authors.initials: XH
authors.lastname: Li
authors.forename: Yue-Ming
authors.initials: YM
authors.lastname: Yan
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D002853:Chromatography, Liquid; D038362:Glycogen Synthase Kinase 3 / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010750:Phosphoproteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation; D018515:Plant Leaves / Q000378:metabolism*; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D020543:Proteome / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D040901:Proteomics / Q000379:methods*; D036226:Seedlings / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D053719:Tandem Mass Spectrometry; D014908:Triticum / Q000378:metabolism*
chemical_list: D010750:Phosphoproteins; D010940:Plant Proteins; D020543:Proteome; D020928:Mitogen-Activated Protein Kinases; D038362:Glycogen Synthase Kinase 3