Cargando…

Pyruvate Homeostasis as a Determinant of Parasite Growth and Metabolic Plasticity in Toxoplasma gondii

Toxoplasma gondii is a widespread intracellular pathogen infecting humans and a variety of animals. Previous studies have shown that Toxoplasma uses glucose and glutamine as the main carbon sources to support asexual reproduction, but neither nutrient is essential. Such metabolic flexibility may all...

Descripción completa

Detalles Bibliográficos
Autores principales: Xia, Ningbo, Ye, Shu, Liang, Xiaohan, Chen, Pu, Zhou, Yanqin, Fang, Rui, Zhao, Junlong, Gupta, Nishith, Yang, Shuzhen, Yuan, Jing, Shen, Bang
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Society for Microbiology 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6561023/
https://www.ncbi.nlm.nih.gov/pubmed/31186321
http://dx.doi.org/10.1128/mBio.00898-19
_version_ 1783426073736773632
author Xia, Ningbo
Ye, Shu
Liang, Xiaohan
Chen, Pu
Zhou, Yanqin
Fang, Rui
Zhao, Junlong
Gupta, Nishith
Yang, Shuzhen
Yuan, Jing
Shen, Bang
author_facet Xia, Ningbo
Ye, Shu
Liang, Xiaohan
Chen, Pu
Zhou, Yanqin
Fang, Rui
Zhao, Junlong
Gupta, Nishith
Yang, Shuzhen
Yuan, Jing
Shen, Bang
author_sort Xia, Ningbo
collection PubMed
description Toxoplasma gondii is a widespread intracellular pathogen infecting humans and a variety of animals. Previous studies have shown that Toxoplasma uses glucose and glutamine as the main carbon sources to support asexual reproduction, but neither nutrient is essential. Such metabolic flexibility may allow it to survive within diverse host cell types. Here, by focusing on the glycolytic enzyme pyruvate kinase (PYK) that converts phosphoenolpyruvate (PEP) into pyruvate, we found that Toxoplasma can also utilize lactate and alanine. We show that catabolism of all indicated carbon sources converges at pyruvate, and maintaining a constant pyruvate supply is critical to parasite growth. Toxoplasma expresses two PYKs: PYK1 in the cytosol and PYK2 in the apicoplast (a chloroplast relict). Genetic deletion of PYK2 did not noticeably affect parasite growth and virulence, which contrasts with the current model of carbon metabolism in the apicoplast. On the other hand, PYK1 was refractory to disruption. Conditional depletion of PYK1 resulted in global alteration of carbon metabolism, amylopectin accumulation, and reduced cellular ATP, leading to severe growth impairment. Notably, the attenuated growth of the PYK1-depleted mutant was partially rescued by lactate or alanine supplementation, and rescue by lactate required lactate dehydrogenase activity to convert it to pyruvate. Moreover, depletion of PYK1 in conjunction with PYK2 ablation led to accentuated loss of apicoplasts and complete growth arrest. Together, our results underline a critical role of pyruvate homeostasis in determining the metabolic flexibility and apicoplast maintenance, and they significantly extend our current understanding of carbon metabolism in T. gondii.
format Online
Article
Text
id pubmed-6561023
institution National Center for Biotechnology Information
language English
publishDate 2019
publisher American Society for Microbiology
record_format MEDLINE/PubMed
spelling pubmed-65610232019-06-14 Pyruvate Homeostasis as a Determinant of Parasite Growth and Metabolic Plasticity in Toxoplasma gondii Xia, Ningbo Ye, Shu Liang, Xiaohan Chen, Pu Zhou, Yanqin Fang, Rui Zhao, Junlong Gupta, Nishith Yang, Shuzhen Yuan, Jing Shen, Bang mBio Research Article Toxoplasma gondii is a widespread intracellular pathogen infecting humans and a variety of animals. Previous studies have shown that Toxoplasma uses glucose and glutamine as the main carbon sources to support asexual reproduction, but neither nutrient is essential. Such metabolic flexibility may allow it to survive within diverse host cell types. Here, by focusing on the glycolytic enzyme pyruvate kinase (PYK) that converts phosphoenolpyruvate (PEP) into pyruvate, we found that Toxoplasma can also utilize lactate and alanine. We show that catabolism of all indicated carbon sources converges at pyruvate, and maintaining a constant pyruvate supply is critical to parasite growth. Toxoplasma expresses two PYKs: PYK1 in the cytosol and PYK2 in the apicoplast (a chloroplast relict). Genetic deletion of PYK2 did not noticeably affect parasite growth and virulence, which contrasts with the current model of carbon metabolism in the apicoplast. On the other hand, PYK1 was refractory to disruption. Conditional depletion of PYK1 resulted in global alteration of carbon metabolism, amylopectin accumulation, and reduced cellular ATP, leading to severe growth impairment. Notably, the attenuated growth of the PYK1-depleted mutant was partially rescued by lactate or alanine supplementation, and rescue by lactate required lactate dehydrogenase activity to convert it to pyruvate. Moreover, depletion of PYK1 in conjunction with PYK2 ablation led to accentuated loss of apicoplasts and complete growth arrest. Together, our results underline a critical role of pyruvate homeostasis in determining the metabolic flexibility and apicoplast maintenance, and they significantly extend our current understanding of carbon metabolism in T. gondii. American Society for Microbiology 2019-06-11 /pmc/articles/PMC6561023/ /pubmed/31186321 http://dx.doi.org/10.1128/mBio.00898-19 Text en Copyright © 2019 Xia et al. https://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International license (https://creativecommons.org/licenses/by/4.0/) .
spellingShingle Research Article
Xia, Ningbo
Ye, Shu
Liang, Xiaohan
Chen, Pu
Zhou, Yanqin
Fang, Rui
Zhao, Junlong
Gupta, Nishith
Yang, Shuzhen
Yuan, Jing
Shen, Bang
Pyruvate Homeostasis as a Determinant of Parasite Growth and Metabolic Plasticity in Toxoplasma gondii
title Pyruvate Homeostasis as a Determinant of Parasite Growth and Metabolic Plasticity in Toxoplasma gondii
title_full Pyruvate Homeostasis as a Determinant of Parasite Growth and Metabolic Plasticity in Toxoplasma gondii
title_fullStr Pyruvate Homeostasis as a Determinant of Parasite Growth and Metabolic Plasticity in Toxoplasma gondii
title_full_unstemmed Pyruvate Homeostasis as a Determinant of Parasite Growth and Metabolic Plasticity in Toxoplasma gondii
title_short Pyruvate Homeostasis as a Determinant of Parasite Growth and Metabolic Plasticity in Toxoplasma gondii
title_sort pyruvate homeostasis as a determinant of parasite growth and metabolic plasticity in toxoplasma gondii
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6561023/
https://www.ncbi.nlm.nih.gov/pubmed/31186321
http://dx.doi.org/10.1128/mBio.00898-19
work_keys_str_mv AT xianingbo pyruvatehomeostasisasadeterminantofparasitegrowthandmetabolicplasticityintoxoplasmagondii
AT yeshu pyruvatehomeostasisasadeterminantofparasitegrowthandmetabolicplasticityintoxoplasmagondii
AT liangxiaohan pyruvatehomeostasisasadeterminantofparasitegrowthandmetabolicplasticityintoxoplasmagondii
AT chenpu pyruvatehomeostasisasadeterminantofparasitegrowthandmetabolicplasticityintoxoplasmagondii
AT zhouyanqin pyruvatehomeostasisasadeterminantofparasitegrowthandmetabolicplasticityintoxoplasmagondii
AT fangrui pyruvatehomeostasisasadeterminantofparasitegrowthandmetabolicplasticityintoxoplasmagondii
AT zhaojunlong pyruvatehomeostasisasadeterminantofparasitegrowthandmetabolicplasticityintoxoplasmagondii
AT guptanishith pyruvatehomeostasisasadeterminantofparasitegrowthandmetabolicplasticityintoxoplasmagondii
AT yangshuzhen pyruvatehomeostasisasadeterminantofparasitegrowthandmetabolicplasticityintoxoplasmagondii
AT yuanjing pyruvatehomeostasisasadeterminantofparasitegrowthandmetabolicplasticityintoxoplasmagondii
AT shenbang pyruvatehomeostasisasadeterminantofparasitegrowthandmetabolicplasticityintoxoplasmagondii