Pyruvate carboxylase plays a crucial role in carbon metabolism of extra- and intracellularly replicating Listeria monocytogenes.
The human pathogen L. monocytogenes is a facultatively intracellular bacterium that survives and replicates in the cytosol of many mammalian cells. The listerial metabolism, especially under intracellular conditions, is still poorly understood. Recent studies analyzed the carbon metabolism of L. monocytogenes by the (13)C isotopologue perturbation method in a defined minimal medium containing [U-(13)C(6)]glucose. It was shown that these bacteria produce oxaloacetate mainly by carboxylation of pyruvate due to an incomplete tricarboxylic acid cycle. Here, we report that a pycA insertion mutant defective in pyruvate carboxylase (PYC) still grows, albeit at a reduced rate, in brain heart infusion (BHI) medium but is unable to multiply in a defined minimal medium with glucose or glycerol as a carbon source. Aspartate and glutamate of the pycA mutant, in contrast to the wild-type strain, remain unlabeled when [U-(13)C(6)]glucose is added to BHI, indicating that the PYC-catalyzed carboxylation of pyruvate is the predominant reaction leading to oxaloacetate in L. monocytogenes. The pycA mutant is also unable to replicate in mammalian cells and exhibits high virulence attenuation in the mouse sepsis model.
Schär
Jennifer
J
Lehrstuhl für Mikrobiologie, Biozentrum, Universität Würzburg, Würzburg, Germany.
Stoll
Regina
R
Schauer
Kristina
K
Loeffler
Daniela I M
DI
Eylert
Eva
E
Joseph
Biju
B
Eisenreich
Wolfgang
W
Fuchs
Thilo M
TM
Goebel
Werner
W
D000818:Animals; D001224:Aspartic Acid / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002244:Carbon / Q000378:metabolism*; D002247:Carbon Isotopes / Q000378:metabolism; D002460:Cell Line; D003470:Culture Media / Q000737:chemistry; D004847:Epithelial Cells / Q000382:microbiology; D005260:Female; D017353:Gene Deletion; D005947:Glucose / Q000378:metabolism; D018698:Glutamic Acid / Q000378:metabolism; D006801:Humans; D008089:Listeria monocytogenes / Q000201:enzymology* / Q000254:growth & development / Q000378:metabolism*; D008264:Macrophages / Q000382:microbiology; D051379:Mice; D008810:Mice, Inbred C57BL; D016254:Mutagenesis, Insertional; D062907:Oxaloacetic Acid / Q000378:metabolism; D011766:Pyruvate Carboxylase / Q000235:genetics / Q000378:metabolism*; D019289:Pyruvic Acid / Q000378:metabolism; D018805:Sepsis / Q000382:microbiology; D014774:Virulence
D001426:Bacterial Proteins; D002247:Carbon Isotopes; D003470:Culture Media; D062907:Oxaloacetic Acid; D001224:Aspartic Acid; D018698:Glutamic Acid; D002244:Carbon; D019289:Pyruvic Acid; D011766:Pyruvate Carboxylase; D005947:Glucose