TY - JOUR
T1 - Central role of pyruvate kinase in carbon co-catabolism of mycobacterium tuberculosis
AU - Noy, Tahel
AU - Vergnolle, Olivia M.
AU - Hartman, Travis E.
AU - Rhee, Kyu Y.
AU - Jacobs, William R.
AU - Berney, Michael
AU - Blanchard, John S.
N1 - Funding Information:
This work was supported, in whole or in part, by National Institutes of Health Grants AI060899 (to J. S. B.), AI26170 (to W. R. J.), AI119573 (to M. B.), and a Burroughs Wellcome Career Award in the Biomedical Sciences (to K. Y. R.).
Publisher Copyright:
©2016 by The American Society for Biochemistry and Molecular Biology, Inc.
PY - 2016/3/25
Y1 - 2016/3/25
N2 - Mycobacterium tuberculosis (Mtb) displays a high degree of metabolic plasticity to adapt to challenging host environments. Genetic evidence suggests that Mtb relies mainly on fatty acid catabolism in the host. However, Mtb also maintains a functional glycolytic pathway and its role in the cellular metabolism of Mtb has yet to be understood. Pyruvate kinase catalyzes the last and rate-limiting step in glycolysis and the Mtb genome harbors one putative pyruvate kinase (pykA, Rv1617). Here we show that pykA encodes an active pyruvate kinase that is allosterically activated by glucose 6-phosphate (Glc-6-P) and adenosine monophosphate (AMP). Deletion of pykA prevents Mtb growth in the presence of fermentable carbon sources and has a cidal effect in the presence of glucose that correlates with elevated levels of the toxic catabolite methylglyoxal. Growth attenuation was also observed in media containing a combination of short chain fatty acids and glucose and surprisingly, in media containing odd and even chain fatty acids alone. Untargeted high sensitivity metabolomics revealed that inactivation of pyruvate kinase leads to accumulation of phosphoenolpyruvate (P-enolpyruvate), citrate, and aconitate, which was consistent with allosteric inhibition of isocitrate dehydrogenase by P-enolpyruvate. This metabolic block could be relieved by addition of the α-ketoglutarate precursor glutamate. Taken together, our study identifies an essential role of pyruvate kinase in preventing metabolic block during carbon co-catabolism in Mtb.
AB - Mycobacterium tuberculosis (Mtb) displays a high degree of metabolic plasticity to adapt to challenging host environments. Genetic evidence suggests that Mtb relies mainly on fatty acid catabolism in the host. However, Mtb also maintains a functional glycolytic pathway and its role in the cellular metabolism of Mtb has yet to be understood. Pyruvate kinase catalyzes the last and rate-limiting step in glycolysis and the Mtb genome harbors one putative pyruvate kinase (pykA, Rv1617). Here we show that pykA encodes an active pyruvate kinase that is allosterically activated by glucose 6-phosphate (Glc-6-P) and adenosine monophosphate (AMP). Deletion of pykA prevents Mtb growth in the presence of fermentable carbon sources and has a cidal effect in the presence of glucose that correlates with elevated levels of the toxic catabolite methylglyoxal. Growth attenuation was also observed in media containing a combination of short chain fatty acids and glucose and surprisingly, in media containing odd and even chain fatty acids alone. Untargeted high sensitivity metabolomics revealed that inactivation of pyruvate kinase leads to accumulation of phosphoenolpyruvate (P-enolpyruvate), citrate, and aconitate, which was consistent with allosteric inhibition of isocitrate dehydrogenase by P-enolpyruvate. This metabolic block could be relieved by addition of the α-ketoglutarate precursor glutamate. Taken together, our study identifies an essential role of pyruvate kinase in preventing metabolic block during carbon co-catabolism in Mtb.
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U2 - 10.1074/jbc.M115.707430
DO - 10.1074/jbc.M115.707430
M3 - Article
C2 - 26858255
AN - SCOPUS:84964830277
VL - 291
SP - 7060
EP - 7069
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 13
ER -