title: Identification of complex relationship between protein kinases and substrates during the cell cycle of HeLa cells by phosphoproteomic analysis.
abstract: Each phase of eukaryotic cell cycle is tightly controlled by multicomponent regulatory networks based on complex relationships of protein phosphorylation. In order to better understand the relationships between kinases and their substrate proteins during the progression of cell cycle, we analyzed phosphoproteome of HeLa cells during G1, S, and G2/M phases of cell cycle using our developed quantitative phosphoproteomic approaches. A total of 4776 high-confidence phosphorylation sites (phosphosites) in 1177 proteins were identified. Bioinformatics analysis for predicting kinase groups revealed that 46 kinase groups could be assigned to 4321 phosphosites. The majority of phosphoproteins harboring two or more phosphosites could be phosphorylated by different kinase groups, in which nine major kinase groups accounted for more than 90% phosphosites. Further analyses showed that approximately half of the examined two phosphosite combinations were correlatively regulated, regardless of whether the kinase groups were same or not. In general, the majority of proteins containing correlated phosphosites had solely co-regulated or counter-regulated phosphosites, and co-regulation was significantly more frequent than counter-regulation, suggesting that the former may be more important for regulating the cell cycle. In conclusion, our findings provide new insights into the complex regulatory mechanisms of protein phosphorylation networks during eukaryotic cell cycle.
authors: Key Laboratory of Systems Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, P. R. China.
authors: Xing-Lin
authors: XL
authors: Yang
authors: Qing-Run
authors: QR
authors: Li
authors: Zhi-Bin
authors: ZB
authors: Ning
authors: Yan
authors: Y
authors: Zhang
authors: Rong
authors: R
authors: Zeng
authors: Jia-Rui
authors: JR
authors: Wu
mesh_terms: D002453:Cell Cycle / Q000502:physiology*; D030562:Databases, Protein; D006367:HeLa Cells / Q000166:cytology / Q000378:metabolism; D006801:Humans; D053858:Metabolic Networks and Pathways; D010750:Phosphoproteins / Q000378:metabolism*; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism*; D040901:Proteomics / Q000379:methods
chemical_list: D010750:Phosphoproteins; D011494:Protein Kinases