A GTP-dependent Vertebrate-type Phosphoenolpyruvate Carboxykinase from Mycobacterium smegmatis

Mukhopadhyay, Biswarup; Concar, Edward M.; Wolfe, R. S.

doi:10.1074/jbc.m008960200

Cited by 43 publications

(46 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Thus, in Mtb, PEPCK is required for and predominantly catalyzes the formation of PEP and does not appear to catalyze the reverse reaction to OAA during metabolism of glucose. These findings are in accordance with the enzymatic properties reported for PEPCK from M. smegmatis (17).…”

Section: Discussionsupporting

confidence: 82%

“…PEPCK catalyzes the guanosine or adenosine mononucleotidedependent reversible conversion of oxaloacetate (OAA) and phosphoenolpyruvate (PEP) (15,16). PEPCK from Mycobacterium smegmatis is GTP-dependent and preferentially catalyzes the gluconeogenic direction, whereby PEP is formed from OAA (17). The gene encoding PEPCK, pckA, is induced by fatty acids in vitro and during growth of Mtb in mice, suggesting a demand for gluconeogenesis during infection (9)(10)(11).…”

mentioning

confidence: 99%

See 1 more Smart Citation

Gluconeogenic carbon flow of tricarboxylic acid cycle intermediates is critical for Mycobacterium tuberculosis to establish and maintain infection

Marrero¹,

Rhee

Schnappinger³

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

314

315

View full text Add to dashboard Cite

Metabolic adaptation to the host niche is a defining feature of the pathogenicity of Mycobacterium tuberculosis (Mtb). In vitro, Mtb is able to grow on a variety of carbon sources, but mounting evidence has implicated fatty acids as the major source of carbon and energy for Mtb during infection. When bacterial metabolism is primarily fueled by fatty acids, biosynthesis of sugars from intermediates of the tricarboxylic acid cycle is essential for growth. The role of gluconeogenesis in the pathogenesis of Mtb however remains unaddressed. Phosphoenolpyruvate carboxykinase (PEPCK) catalyzes the first committed step of gluconeogenesis. We applied genetic analyses and 13 C carbon tracing to confirm that PEPCK is essential for growth of Mtb on fatty acids and catalyzes carbon flow from tricarboxylic acid cycle-derived metabolites to gluconeogenic intermediates. We further show that PEPCK is required for growth of Mtb in isolated bone marrow-derived murine macrophages and in mice. Importantly, Mtb lacking PEPCK not only failed to replicate in mouse lungs but also failed to survive, and PEPCK depletion during the chronic phase of infection resulted in mycobacterial clearance. Mtb thus relies on gluconeogenesis throughout the infection. PEPCK depletion also attenuated Mtb in IFNγ-deficient mice, suggesting that this enzyme represents an attractive target for chemotherapy.carbon metabolism | gluconeogenesis | metabolomics | microbial pathogenesis | phosphoenolpyruvate carboxykinase

show abstract

Section: Discussionsupporting

confidence: 82%

mentioning

confidence: 99%

Gluconeogenic carbon flow of tricarboxylic acid cycle intermediates is critical for Mycobacterium tuberculosis to establish and maintain infection

Marrero¹,

Rhee

Schnappinger³

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

314

315

View full text Add to dashboard Cite

show abstract

“…The kinetic data obtained in the presence of 15 nM Pck indicated that Pck can catalyze reactions in both directions (PEP formation or OAA formation) with different efficiencies that depend on multiple factors (see Fig. 3 for reaction schemes) (25,26). The concentration dependences of initial reaction velocities for individual components of the reaction mixtures followed typical Michaelis-Menten curves (Fig.…”

Section: Resultsmentioning

confidence: 90%

“…However, the inhibiting concentrations of CO 2 or hydrogen carbonate (over 100 mM) are much higher than the typical physiological concentrations of 10 -50 mM (27). Comparison of the kinetic parameters for Pck forward and reverse reactions clearly indicates that the enzyme belongs to the GTP-dependent enzyme family, as does the homologous enzyme in Mycobacterium smegmatis (25) and Pcks from higher eukaryotic species, such as mice, rats, chickens, and humans. The results from kinetic measurements showed that MTb Pck can operate in both directions in vitro.…”

Section: Resultsmentioning

confidence: 99%

Mycobacterium tuberculosis Phosphoenolpyruvate Carboxykinase Is Regulated by Redox Mechanisms and Interaction with Thioredoxin

Machová

Snášel

Zimmermann

et al. 2014

Journal of Biological Chemistry

View full text Add to dashboard Cite

Background: Phosphoenolpyruvate carboxykinase (Pck) catalyzes the interconversion of phosphoenolpyruvate and oxaloacetate but typically prefers gluconeogenic formation of phosphoenolpyruvate. Results: Interactions of Mycobacterium tuberculosis (MTb) Pck with thioredoxin and reducing environments favor the anaplerotic oxaloacetate synthesis. Conclusion: A mechanism explaining the regulation of Pck functions is proposed. Significance: Regulation of Pck is important for the MTb non-replicative state associated with latent tuberculosis infection.

show abstract

“…An analysis of the whole genome sequence of M. tuberculosis shows that this bacterium possesses a putative GTP-dependent PEPCK encoded by the gene pckA. Mukhopadhyay et al (2001) showed that PEPCK from Mycobacterium smegmatis preferred the gluconeogenesis/ glycerogenesis direction. Recently, we confirmed that disruption of pckA in M. smegmatis inhibited the growth of the bacteria on acetate and palmitate (unpublished data).…”

Section: Introductionmentioning

confidence: 99%

pckA-deficient Mycobacterium bovis BCG shows attenuated virulence in mice and in macrophages

Liu

Russell

2003

Microbiology

View full text Add to dashboard Cite

Phosphoenolpyruvate carboxykinase (PEPCK) catalyses the reversible decarboxylation and phosphorylation of oxaloacetate (OAA) to form phosphoenolpyruvate (PEP). In this study, the regulation of the PEPCK-encoding gene pckA was examined through the evaluation of green fluorescent protein expression driven by the pckA promoter. The results showed that pckA was upregulated by acetate or palmitate but downregulated by glucose. Deletion of the pckA gene of Mycobacterium bovis BCG led to a reduction in the capacity of the bacteria to infect and survive in macrophages. Moreover, mice infected with DpckA BCG were able to reduce the bacterial load much more effectively than mice infected with the parental wild-type bacteria. This attenuated virulence was reflected in the degree of pathology, where granuloma formation was diminished both in numbers and degree. The data indicate that PEPCK activity is important during establishment of infection. Whether its role is in the gluconeogenic pathway for carbohydrate formation or in the conversion of PEP to OAA to maintain the TCA cycle remains to be determined.

show abstract

A GTP-dependent Vertebrate-type Phosphoenolpyruvate Carboxykinase from Mycobacterium smegmatis

Cited by 43 publications

References 52 publications

Gluconeogenic carbon flow of tricarboxylic acid cycle intermediates is critical for Mycobacterium tuberculosis to establish and maintain infection

Gluconeogenic carbon flow of tricarboxylic acid cycle intermediates is critical for Mycobacterium tuberculosis to establish and maintain infection

Mycobacterium tuberculosis Phosphoenolpyruvate Carboxykinase Is Regulated by Redox Mechanisms and Interaction with Thioredoxin

pckA-deficient Mycobacterium bovis BCG shows attenuated virulence in mice and in macrophages

Contact Info

Product

Resources

About