Protein Phosphatase 2C of Toxoplasma Gondii Interacts with Human SSRP1 and Negatively Regulates Cell Apoptosis.

Xue Juan Gao; Jun Xia Feng; Sen Zhu; Xiao Hui Liu; Isabelle Tardieux; Lang Xia Liu

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Protein Phosphatase 2C of Toxoplasma Gondii Interacts with Human SSRP1 and Negatively Regulates Cell Apoptosis.

Author: Xue Juan GAO ¹ ; Jun Xia FENG ¹ ; Sen ZHU ¹ ; Xiao Hui LIU ¹ ; Isabelle TARDIEUX ² ; Lang Xia LIU ¹
Author Information

1. Key Laboratory of Functional Protein Research of Guangdong Higher Education Institutes, Institute of Life and Health Engineering, Jinan University, Guangzhou 510632, Guangdong, China.
2. Institut Cochin, Université Descartes, Team FRM 'Barriers and Pathogens', 22 Rue Méchain, Paris 75014, France.
Publication Type:Journal Article
Keywords: Apoptosis; SSRP1; TgPP2C; Toxoplasma gondii
MeSH: Apoptosis; Blotting, Western; DNA-Binding Proteins; genetics; metabolism; Flow Cytometry; HeLa Cells; High Mobility Group Proteins; genetics; metabolism; Humans; Immunoprecipitation; Phosphoprotein Phosphatases; genetics; metabolism; Protein Phosphatase 2C; Toxoplasma; enzymology; Transcriptional Elongation Factors; genetics; metabolism; Two-Hybrid System Techniques
From: Biomedical and Environmental Sciences 2014;27(11):883-893
CountryChina
Language:English
Abstract:
OBJECTIVEThe protozoan Toxoplasma gondii expresses large amounts of a 37 kDa Type 2C serine-threonine phosphatase, the so-called TgPP2C which has been suggested to contribute to parasite growth regulation. Ectopic expression in mammalian cells also indicated that the enzyme could regulate growth and survival. In this study, we aimed to investigate the interaction of TgPP2C with human SSRP1 (structure-specific recognition protein 1) and the effects of TgPP2C on cell viability.
METHODSThe yeast two hybrid system, His-tag pull-down and co-immunoprecipitation assays were used to confirm the interaction of TgPP2C with SSRP1 and determine the binding domain on SSRP1. The evaluation of cell apoptosis was performed using cleaved caspase-3 antibody and Annexin-V/PI kit combined with flow cytometry.
RESULTSWe identified human SSRP1 as an interacting partner of TgPP2C. The C-terminal region of SSRP1 including the amino acids 471 to 538 was specifically mapped as the region responsible for interaction with TgPP2C. The overexpression of TgPP2C down-regulated cell apoptosis and negatively regulated apoptosis induced by DRB, casein kinase II (CKII) inhibitor, through enhanced interaction with SSRP1.
CONCLUSIONTgPP2C may be a parasitic factor capable of promoting cell survival through interaction with the host protein SSRP1, thereby creating a favorable environment for parasite growth.