Identification of in vivo protein phosphorylation sites in human pathogen Schistosoma japonicum by a phosphoproteomic approach

• Published in: Journal of proteomics 2012-01, Vol.75 (3), p.868-877
• Main Authors: Luo, Rong, Zhou, Chunjing, Lin, Jiaojiao, Yang, Dehao, Shi, Yaojun, Cheng, Guofeng
• Format: Article
• Language: English
• Subjects: adults; affinity chromatography; Biological and medical sciences; cysteine; Development; Diverse techniques; drugs; epidermal growth factor receptors; Fundamental and applied biological sciences. Psychology; heat shock proteins; humans; IMAC; in vivo; Molecular and cellular biology; NanoLC–ESI-MS/MS; pathogens; phosphoproteins; Phosphorylation; protein phosphorylation; Schistosoma japonicum; schistosomiasis; schistosomula
• ISSN: 1874-3919
• DOI: 10.1016/j.jprot.2011.10.003

Schistosome is the causative agent of human schistosomiasis and related animal disease. Reversible protein phosphorylation plays a key role in signaling processing that are vital for a cell and organism. However, it remains to be undercharacterized in schistosomes. In the present study, we characterized in vivo protein phosphorylation events in different developmental stages (schistosomula and adult worms) of Schistosoma japonicum by using microvolume immobilized metal-ion affinity chromatography (IMAC) pipette tips coupled to nanoLC–ESI-MS/MS. In total, 127 distinct phosphorylation sites were identified in 92 proteins in S. japonicum. A comparison of the phosphopeptides identified between the schistosomula and the adult worms revealed 30 phosphoproteins co-detected in both of the two worms. These proteins included several signal molecules and enzymes such as 14-3-3 protein, cysteine string protein, heat shock protein 90, epidermal growth factor receptor pathway substrate 8, proliferation-associated protein 2G4, peptidyl-prolyl isomerase G, phosphofructokinase and thymidylate kinase. Additionally, the phosphorylation sites were examined for phosphorylation specific motif and evolutionarily conservation. The study represents the first attempt to determine in vivo protein phosphorylation in S. japonicum by using a phosphoproteomic approach. The results by providing an inventory of phosphorylated proteins may facilitate to further understand the mechanisms involved in schistosome development and growth, and then may result in the development of novel vaccine candidates and drug targets for schistosomiasis control. [Display omitted] ► in vivo protein phosphorylation sites were determined in Schistosoma japonicum. ► A phosphoproteomic approach was applied in two different stages of schistosomes. ► We identified 127 distinct phosphorylation sites in 92 proteins in S. japonicum. ► 30 phosphoproteins were shown to be co-detected in both the two stages. ► These co-detected phosphoproteins included several signal molecules and enzymes.