PknG senses amino acid availability to control metabolism and virulence of Mycobacterium tuberculosis

PLoS Pathogens

Andrew R. Bottrill¹  Natalie R. Lazar-Adler¹  Helen M. O’Hare²  Barbara Rieck²  Liem Nguyen³  Riccardo Manganelli⁴  Giulia Degiacomi⁴  Francesca Boldrin⁴  Alessandro Cascioferro⁵  Fabien le Chevalier⁵  Wafa Frigui⁵  Roland Brosch⁵  Pedro M. Alzari⁶  Marco Bellinzoni⁶  María-Natalia Lisa⁶  Uwe Sauer⁷  Michael Zimmermann⁷ 

[1] Core Biotechnology Services, University of Leicester, Leicester, United Kingdom;Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, United Kingdom;Department of Molecular Biology and Microbiology, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America;Department of Molecular Medicine, University of Padua, Padova, Italy;Institut Pasteur, Integrated Mycobacterial Pathogenomics Unit, Paris, France;Institut Pasteur, Unité de Microbiologie Structurale and CNRS-UMR3528, Paris, France;Institute of Molecular Systems Biology, ETH Zurich, Zurich, Switzerland

关键词: Mycobacterium tuberculosis;    Phosphorylation;    Glutamate;    Metabolites;    Asparagine;    Macrophages;    Amino acid metabolism;    Metabolomics;   

DOI  :  10.1371/journal.ppat.1006399

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

Sensing and response to changes in nutrient availability are essential for the lifestyle of environmental and pathogenic bacteria. Serine/threonine protein kinase G (PknG) is required for virulence of the human pathogen Mycobacterium tuberculosis, and its putative substrate GarA regulates the tricarboxylic acid cycle in M. tuberculosis and other Actinobacteria by protein-protein binding. We sought to understand the stimuli that lead to phosphorylation of GarA, and the roles of this regulatory system in pathogenic and non-pathogenic bacteria. We discovered that M. tuberculosis lacking garA was severely attenuated in mice and macrophages and furthermore that GarA lacking phosphorylation sites failed to restore the growth of garA deficient M. tuberculosis in macrophages. Additionally we examined the impact of genetic disruption of pknG or garA upon protein phosphorylation, nutrient utilization and the intracellular metabolome. We found that phosphorylation of GarA requires PknG and depends on nutrient availability, with glutamate and aspartate being the main stimuli. Disruption of pknG or garA caused opposing effects on metabolism: a defect in glutamate catabolism or depletion of intracellular glutamate, respectively. Strikingly, disruption of the phosphorylation sites of GarA was sufficient to recapitulate defects caused by pknG deletion. The results suggest that GarA is a cellular target of PknG and the metabolomics data demonstrate that the function of this signaling system is in metabolic regulation. This function in amino acid homeostasis is conserved amongst the Actinobacteria and provides an example of the close relationship between metabolism and virulence.

【 授权许可】

CC BY