The Listeria monocytogenes PASTA Kinase PrkA and Its Substrate YvcK Are Required for Cell Wall Homeostasis, Metabolism, and Virulence.
Obstacles to bacterial survival and replication in the cytosol of host cells, and the mechanisms used by bacterial pathogens to adapt to this niche are not well understood. Listeria monocytogenes is a well-studied Gram-positive foodborne pathogen that has evolved to invade and replicate within the host cell cytosol; yet the mechanisms by which it senses and responds to stress to survive in the cytosol are largely unknown. To assess the role of the L. monocytogenes penicillin-binding-protein and serine/threonine associated (PASTA) kinase PrkA in stress responses, cytosolic survival and virulence, we constructed a ΔprkA deletion mutant. PrkA was required for resistance to cell wall stress, growth on cytosolic carbon sources, intracellular replication, cytosolic survival, inflammasome avoidance and ultimately virulence in a murine model of Listeriosis. In Bacillus subtilis and Mycobacterium tuberculosis, homologues of PrkA phosphorylate a highly conserved protein of unknown function, YvcK. We found that, similar to PrkA, YvcK is also required for cell wall stress responses, metabolism of glycerol, cytosolic survival, inflammasome avoidance and virulence. We further demonstrate that similar to other organisms, YvcK is directly phosphorylated by PrkA, although the specific site(s) of phosphorylation are not highly conserved. Finally, analysis of phosphoablative and phosphomimetic mutants of YvcK in vitro and in vivo demonstrate that while phosphorylation of YvcK is irrelevant to metabolism and cell wall stress responses, surprisingly, a phosphomimetic, nonreversible negative charge of YvcK is detrimental to cytosolic survival and virulence in vivo. Taken together our data identify two novel virulence factors essential for cytosolic survival and virulence of L. monocytogenes. Furthermore, our data demonstrate that regulation of YvcK phosphorylation is tightly controlled and is critical for virulence. Finally, our data suggest that yet to be identified substrates of PrkA are essential for cytosolic survival and virulence of L. monocytogenes and illustrate the importance of studying protein phosphorylation in the context of infection.
Department of Medical Microbiology and Immunology University of Wisconsin-Madison, School of Medicine and Public Health, Madison, Wisconsin.
Daniel A
DA
Pensinger
Department of Medical Microbiology and Immunology University of Wisconsin-Madison, School of Medicine and Public Health, Madison, Wisconsin.|Department of Medicine, University of Wisconsin-Madison, School of Medicine and Public Health, Madison, Wisconsin.
Kyle M
KM
Boldon
Department of Medical Microbiology and Immunology University of Wisconsin-Madison, School of Medicine and Public Health, Madison, Wisconsin.
Grischa Y
GY
Chen
Department of Medical Microbiology and Immunology University of Wisconsin-Madison, School of Medicine and Public Health, Madison, Wisconsin.
William J B
WJ
Vincent
Department of Medical Microbiology and Immunology University of Wisconsin-Madison, School of Medicine and Public Health, Madison, Wisconsin.
Kyle
K
Sherman
Department of Medical Microbiology and Immunology University of Wisconsin-Madison, School of Medicine and Public Health, Madison, Wisconsin.
Meng
M
Xiong
Department of Medical Microbiology and Immunology University of Wisconsin-Madison, School of Medicine and Public Health, Madison, Wisconsin.
Adam J
AJ
Schaenzer
Department of Medical Microbiology and Immunology University of Wisconsin-Madison, School of Medicine and Public Health, Madison, Wisconsin.
Emily R
ER
Forster
Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, North Carolina.
Jörn
J
Coers
Department of Medical Microbiology and Immunology University of Wisconsin-Madison, School of Medicine and Public Health, Madison, Wisconsin.|Department of Medicine, University of Wisconsin-Madison, School of Medicine and Public Health, Madison, Wisconsin.|W. S. Middleton Memorial Veteran's Hospital, Madison, Wisconsin.
Rob
R
Striker
Department of Medical Microbiology and Immunology University of Wisconsin-Madison, School of Medicine and Public Health, Madison, Wisconsin.
John-Demian
http://orcid.org/0000-0001-9367-794X
JD
Sauer
D000818:Animals; D015153:Blotting, Western; D002473:Cell Wall / Q000378:metabolism*; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D004195:Disease Models, Animal; D006706:Homeostasis / Q000502:physiology*; D008089:Listeria monocytogenes / Q000472:pathogenicity*; D008088:Listeriosis / Q000378:metabolism*; D013058:Mass Spectrometry; D051379:Mice; D008810:Mice, Inbred C57BL; D008826:Microbial Sensitivity Tests; D014774:Virulence / Q000502:physiology*; D037521:Virulence Factors / Q000378:metabolism*
D037521:Virulence Factors; D017868:Cyclic AMP-Dependent Protein Kinases