TY - JOUR
T1 - A human proteome array approach to identifying key host proteins targeted by toxoplasma kinase ROP18
AU - Yang, Zhaoshou
AU - Hou, Yongheng
AU - Hao, Taofang
AU - Rho, Hee-Sool
AU - Wan, Jun
AU - Luan, Yizhao
AU - Gao, Xin
AU - Yao, Jianping
AU - Pan, Aihua
AU - Xie, Zhi
AU - Qian, Jiang
AU - Liao, Wanqin
AU - Zhu, Heng
AU - Zhou, Xingwang
N1 - Publisher Copyright:
© 2017 by The American Society for Biochemistry and Molecular Biology, Inc.
PY - 2017/3
Y1 - 2017/3
N2 - Toxoplasma kinase ROP18 is a key molecule responsible for the virulence of Toxoplasma gondii; however, the mechanisms by which ROP18 exerts parasite virulence via interaction with host proteins remain limited to a small number of identified substrates. To identify a broader array of ROP18 substrates, we successfully purified bioactive mature ROP18 and used it to probe a human proteome array. Sixty eight new putative host targets were identified. Functional annotation analysis suggested that these proteins have a variety of functions, including metabolic process, kinase activity and phosphorylation, cell growth, apoptosis and cell death, and immunity, indicating a pleiotropic role of ROP18 kinase. Among these proteins, four candidates, p53, p38, UBE2N, and Smad1, were further validated. We demonstrated that ROP18 targets p53, p38, UBE2N, and Smad1 for degradation. Importantly, we demonstrated that ROP18 phosphorylates Smad1 Ser-187 to trigger its proteasome-dependent degradation. Further functional characterization of the substrates of ROP18 may enhance understanding of the pathogenesis of Toxoplasma infection and provide new therapeutic targets. Similar strategies could be used to identify novel host targets for other microbial kinases functioning at the pathogen-host interface.
AB - Toxoplasma kinase ROP18 is a key molecule responsible for the virulence of Toxoplasma gondii; however, the mechanisms by which ROP18 exerts parasite virulence via interaction with host proteins remain limited to a small number of identified substrates. To identify a broader array of ROP18 substrates, we successfully purified bioactive mature ROP18 and used it to probe a human proteome array. Sixty eight new putative host targets were identified. Functional annotation analysis suggested that these proteins have a variety of functions, including metabolic process, kinase activity and phosphorylation, cell growth, apoptosis and cell death, and immunity, indicating a pleiotropic role of ROP18 kinase. Among these proteins, four candidates, p53, p38, UBE2N, and Smad1, were further validated. We demonstrated that ROP18 targets p53, p38, UBE2N, and Smad1 for degradation. Importantly, we demonstrated that ROP18 phosphorylates Smad1 Ser-187 to trigger its proteasome-dependent degradation. Further functional characterization of the substrates of ROP18 may enhance understanding of the pathogenesis of Toxoplasma infection and provide new therapeutic targets. Similar strategies could be used to identify novel host targets for other microbial kinases functioning at the pathogen-host interface.
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U2 - 10.1074/mcp.M116.063602
DO - 10.1074/mcp.M116.063602
M3 - Article
C2 - 28087594
AN - SCOPUS:85016080136
SN - 1535-9476
VL - 16
SP - 469
EP - 484
JO - Molecular and Cellular Proteomics
JF - Molecular and Cellular Proteomics
IS - 3
ER -