iTRAQ-based phosphoproteomic analysis reveals host cell's specific responses to Toxoplasma gondii at the phases of invasion and prior to egress

• Published in: Biochimica et biophysica acta. Proteins and proteomics Vol. 1867; no. 3; pp. 202 - 212
• Main Authors: He, Cheng, Kong, Ling, Puthiyakunnon, Santhosh, Wei, Hai-Xia, Zhou, Li-Juan, Peng, Hong-Juan
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.03.2019
• Subjects: Apoptosis; Host cell immunity; iTRAQ; Phosphoproteomic analysis; Toxoplasma gondii; iTRAQ; Host cell immunity; Toxoplasma gondii; Phosphoproteomic analysis; Apoptosis
• ISSN: 1570-9639; 1878-1454
• DOI: 10.1016/j.bbapap.2018.12.004

Protein phosphorylation plays a key role in host cell-T. gondii interaction. However, the phosphoproteome data of host cell at various phases of T. gondii infection has not been thoroughly described. In this study, we assessed the host phosphoproteome data with isobaric tags for relative and absolute quantification (iTRAQ) method during the phases of T. gondii invasion (30 min post infection, PI) and prior to egress (28 h PI). Our iTRAQ analysis revealed a total of 665 phosphoproteins, among which the significantly regulated phosphoproteins in different between-group comparisons were further analyzed. Functional analysis of these significantly regulated phosphoproteins suggested that T. gondii modulated host cell processes through phosphorylation including cell cycle regulation, inducing apoptosis, blocking the synthesis of some inflammatory factors, mediating metabolism to support its proliferation at the infection phase prior to egress, and utilizing membrane and energy from host cell, reorganizing cytoskeleton to favor its invasion and PV formation at the phase of invasion. The phosphorylation level of Smad2, CTNNA1, and HSPB1 identified with western blot revealed a consistent trend of change with iTRAQ result. These newly identified and significantly regulated phosphoproteins from our phosphoproteome data may provide new clues to unravel the host cell's complex reaction against T. gondii infection and the interaction between the host cell and T. gondii. •A phosphoproteomic analysis based on iTRAQ was performed on host cells infected with T. gondii for 30 min and 28 h.•Significantly regulated phosphoproteins were identified on comparing between-groups of uninfected, 30 min, and 28 h infection.•Cytoskeleton and membrane changes were emphasized at 30 m infection and the cell cycle regulation was enriched at 28 h infection.•Host cell biological processes were extensively regulated, and dominated differently at various phases of infection.