title: Global iTRAQ-based proteomic profiling of Toxoplasma gondii oocysts during sporulation.
abstract: Toxoplasma gondii is a medically and economically important protozoan parasite. However, the molecular mechanisms of its sporulation remain largely unknown. Here, we applied iTRAQ coupled with 2D LC-MS/MS proteomic analysis to investigate the proteomic expression profile of T. gondii oocysts during sporulation. Of the 2095 non-redundant proteins identified, 587 were identified as differentially expressed proteins (DEPs). Based on Gene Ontology enrichment and KEGG pathway analyses the majority of these DEPs were found related to the metabolism of amino acids, carbon and energy. Protein interaction network analysis generated by STRING identified ATP-citrate lyase (ACL), GMP synthase, IMP dehydrogenase (IMPDH), poly (ADP-ribose) glycohydrolase (PARG), and bifunctional dihydrofolate reductase-thymidylate synthase (DHFR-TS) as the top five hubs. We also identified 25 parasite virulence factors that were expressed at relatively high levels in sporulated oocysts compared to non-sporulated oocysts, which might contribute to the infectivity of mature oocysts. Considering the importance of oocysts in the dissemination of toxoplasmosis these findings may help in the search of protein targets with a key role in infectiousness and ecological success of oocysts, creating new opportunities for the development of better means for disease prevention.
  
  
  
  The development of new preventative interventions against T. gondii infection relies on an improved understanding of the proteome and chemical pathways of this parasite. To identify proteins required for the development of environmentally resistant and infective T. gondii oocysts, we compared the proteome of non-sporulated (immature) oocysts with the proteome of sporulated (mature, infective) oocysts. iTRAQ 2D-LC-MS/MS analysis revealed proteomic changes that distinguish non-sporulated from sporulated oocysts. Many of the differentially expressed proteins were involved in metabolic pathways and 25 virulence factors were identified upregulated in the sporulated oocysts. This work provides the first quantitative characterization of the proteomic variations that occur in T. gondii oocyst stage during sporulation.
authors.affiliation: National Animal Protozoa Laboratory and College of Veterinary Medicine, China Agricultural University, Beijing 100193, PR China; State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, PR China.
authors.forename: Chun-Xue
authors.initials: CX
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, PR China.
authors.forename: Xing-Quan
authors.initials: XQ
authors.lastname: Zhu
authors.affiliation: Faculty of Medicine and Health Sciences, School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD, UK.
authors.forename: Hany M
authors.initials: HM
authors.lastname: Elsheikha
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, PR China; College of Animal Science and Technology, Anhui Agricultural University, Hefei, Anhui Province 230036, PR China.
authors.forename: Shuai
authors.initials: S
authors.lastname: He
authors.affiliation: School of Basic Medicine, Dali University, Dali, Yunnan Province 671000, PR China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Li
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, PR China. Electronic address: zhoudonghui@caas.cn.
authors.forename: Dong-Hui
authors.initials: DH
authors.lastname: Zhou
authors.affiliation: National Animal Protozoa Laboratory and College of Veterinary Medicine, China Agricultural University, Beijing 100193, PR China. Electronic address: suoxun@cau.edu.cn.
authors.forename: Xun
authors.initials: X
authors.lastname: Suo
mesh_terms: D002853:Chromatography, Liquid; D018507:Gene Expression Regulation, Developmental; D008018:Life Cycle Stages; D033661:Oocysts / Q000737:chemistry*; D060066:Protein Interaction Maps; D020543:Proteome / Q000032:analysis* / Q000378:metabolism; D040901:Proteomics / Q000379:methods; D015800:Protozoan Proteins / Q000032:analysis*; D033761:Spores, Protozoan; D053719:Tandem Mass Spectrometry; D014122:Toxoplasma / Q000737:chemistry*; D014123:Toxoplasmosis; D037521:Virulence Factors / Q000032:analysis
chemical_list: D020543:Proteome; D015800:Protozoan Proteins; D037521:Virulence Factors
keywords: Oocyst; Proteomics; Sporulation; Toxoplasma gondii; iTRAQ