文献类型： 外文期刊

第一作者： Lyu, Congcong

作者： Lyu, Congcong;Chen, Yukun;Meng, Yanan;Yang, Jichao;Ye, Shu;Niu, Zhipeng;Gupta, Nishith;Shen, Bang;Shen, Bang;Lyu, Congcong;Shen, Bang;Lyu, Congcong;EI-Debs, Issam;Gupta, Nishith;Gupta, Nishith;Shen, Bang

作者机构： Huazhong Agr Univ, Coll Vet Med, State Key Lab Agr Microbiol, Wuhan, Hubei, Peoples R China;Hubei Hongshan Lab, Wuhan, Hubei, Peoples R China;Huazhong Agr Univ, Shenzhen Inst Nutr & Hlth, Shenzhen, Guangdong, Peoples R China;Humboldt Univ, Fac Life Sci, Dept Mol Parasitol, Berlin, Germany;Birla Inst Technol & Sci Pilani BITS P, Dept Biol Sci, Intracellular Parasite Educ & Res Labs iPEARL, Hyderabad, India;Chinese Acad Agr Sci, Agr Genom Inst Shenzhen, Shenzhen Branch, Guangdong Lab Lingnan Modern Agr,Genome Anal Lab,M, Shenzhen, Guangdong, Peoples R China

关键词： mitochondrial pyruvate carrier; glycolysis; TCA cycle; branched-chain ketoacid dehydrogenase; acetyl-CoA

期刊名称：MICROBIOLOGY SPECTRUM （ 2022影响因子：3.7； 五年影响因子：5.9 ）

ISSN： 2165-0497

年卷期： 2023 年 11 卷 2 期

页码：

收录情况： SCI

摘要： Toxoplasma gondii is an obligate intracellular parasite capable of infecting humans and animals. The organism has extraordinary metabolic resilience that allows it to establish parasitism in varied nutritional milieus of diverse host cells. Our earlier work has shown that, despite flexibility in the usage of glucose and glutamine as the major carbon precursors, the production of pyruvate by glycolytic enzymes is central to the parasite's growth. Pyruvate is metabolized in a number of subcellular compartments, including the mitochondrion, apicoplast, and cytosol. With the objective of examining the mechanism and importance of the mitochondrial pool of pyruvate imported from the cytosol, we identified the conserved mitochondrial pyruvate carrier (MPC) complex, consisting of two subunits, MPC1 and MPC2, in T. gondii. The two parasite proteins could complement a yeast mutant deficient in growth on leucine and valine. Genetic ablation of either one or both subunits reduced the parasite's growth, mimicking the deletion of branched-chain ketoacid dehydrogenase (BCKDH), which has been reported to convert pyruvate into acetyl-coenzyme A (CoA) in the mitochondrion. Metabolic labeling of the MPC mutants by isotopic glucose revealed impaired synthesis of acetyl-CoA, correlating with a global decrease in carbon flux through glycolysis and the tricarboxylic acid (TCA) cycle. Disruption of MPC proteins exerted only a modest effect on the parasite's virulence in mice, further highlighting its metabolic flexibility. In brief, our work reveals the modus operandi of pyruvate transport from the cytosol to the mitochondrion in the parasite, providing the missing link between glycolysis and the TCA cycle in T. gondii.IMPORTANCE T. gondii is a zoonotic parasite capable of infecting many warm-blooded organisms, including humans. Among others, a feature that allows it to parasitize multiple hosts is its exceptional metabolic plasticity. Although T. gondii can utilize different carbon sources, pyruvate homeostasis is critical for parasite growth. Pyruvate is produced primarily in the cytosol but metabolized in other organelles, such as the mitochondrion and apicoplast. The mechanism of import and physiological significance of pyruvate in these organelles remains unclear. Here, we identified the transporter of cytosol-derived pyruvate into the mitochondrion and studied its constituent subunits and their relevance. Our results show that cytosolic pyruvate is a major source of acetyl-CoA in the mitochondrion and that the mitochondrial pyruvate transporter is needed for optimal parasite growth. The mutants lacking the transporter are viable and virulent in a mouse model, underscoring the metabolic plasticity in the parasite's mitochondrion. T. gondii is a zoonotic parasite capable of infecting many warm-blooded organisms, including humans. Among others, a feature that allows it to parasitize multiple hosts is its exceptional metabolic plasticity.

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