In Escherichia coli -- and likely other bacteria -- high-energy intermediates of central metabolism [e.g. acetyl phosphate (acP) and acetyl-coenzyme A (acCoA)] appear to control global gene expression -- at least in part - through a subset of signaling proteins called two-component signal transduction (2CST) response regulators (RRs). The high-energy status of acP and acCoA makes each an excellent donor: acP can donate its phosphoryl group, while acCoA can donate its acetyl group. Coupled with their central position in metabolism, these abilities make acP and acCoA ideally suited to indicate nutritional status and thereby impact a variety of cellular processes. This proposal will test key aspects of the following hypothesis. Cells exposed to excess carbon experience a central metabolic stress associated with their inability to recycle coenzymeA (CoA) rapidly enough. Because CoA is present in limiting amounts, the acCoA:CoA ratio becomes large. To recycle the metabolically essential CoA, some of the excess acetyl groups pass from CoA to inorganic phosphate. This process results in the synthesis of acP, which has been proposed to donate its phosphoryl group to a subset of 2CSTRRs. Alternatively or simultaneously, other acetyl groups can be donated directly to a second subset of RRs, thereby altering their function. This hypothesis is broadly based on the following observations: (i) cells manipulate the ratio of acCoA and acP during growth and in response to the quality and quantity of carbon source. (ii) cells respond globally to variations in the concentrations of both high-energy central metabolites;(iii) the response to acP depends on the action of at least one RR and likely more;(iv) two promoters, each dependent on a different RR, appear to respond to the status of the acCoA pool;and (v) acCoA has been shown to donate its acetyl group to 2 purified RRs. 2CST pathways regulate diverse processes associated with biofilm development and pathogenesis. Because humans do not express 2CST pathways, the abilities of acP and acCoA to modify RRs represent a prime target for anti-microbial strategies.

Public Health Relevance

This proposal will test the hypothesis that acetyl coenzyme A and acetyl phosphate, high-energy intermediates of central metabolism, can modify - by acetylation or phosphorylation, respectively - and thereby alter the function of signaling proteins that contribute to biofilm development by and virulence of diverse pathogens. Because humans do not express these signaling proteins, called response regulators, these interactions represent a prime target for anti-microbial strategies.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM066130-08
Application #
8265824
Study Section
Special Emphasis Panel (ZRG1-IDM-H (02))
Program Officer
Reddy, Michael K
Project Start
2004-05-01
Project End
2014-02-28
Budget Start
2012-03-01
Budget End
2014-02-28
Support Year
8
Fiscal Year
2012
Total Cost
$311,366
Indirect Cost
$103,095
Name
Loyola University Chicago
Department
Microbiology/Immun/Virology
Type
Schools of Medicine
DUNS #
791277940
City
Maywood
State
IL
Country
United States
Zip Code
60153
Beckham, Katherine S H; Connolly, James P R; Ritchie, Jennifer M et al. (2014) The metabolic enzyme AdhE controls the virulence of Escherichia coli?O157:H7. Mol Microbiol 93:199-211
Kuhn, Misty L; Zemaitaitis, Bozena; Hu, Linda I et al. (2014) Structural, kinetic and proteomic characterization of acetyl phosphate-dependent bacterial protein acetylation. PLoS One 9:e94816
Josenhans, Christine; Jung, Kirsten; Rao, Christopher V et al. (2014) A tale of two machines: a review of the BLAST meeting, Tucson, AZ, 20-24 January 2013. Mol Microbiol 91:6-25
Hu, Linda I; Chi, Bui Khanh; Kuhn, Misty L et al. (2013) Acetylation of the response regulator RcsB controls transcription from a small RNA promoter. J Bacteriol 195:4174-86
Minato, Yusuke; Fassio, Sara R; Wolfe, Alan J et al. (2013) Central metabolism controls transcription of a virulence gene regulator in Vibrio cholerae. Microbiology 159:792-802
Reimann, Sylvia A; Wolfe, Alan J (2011) Exposure to Glycolytic Carbon Sources Reveals a Novel Layer of Regulation for the MalT Regulon. Int J Microbiol 2011:107023
Lima, Bruno P; Antelmann, Haike; Gronau, Katrin et al. (2011) Involvement of protein acetylation in glucose-induced transcription of a stress-responsive promoter. Mol Microbiol 81:1190-204
Reimann, Sylvia A; Wolfe, Alan J (2011) Constitutive expression of the maltoporin LamB in the absence of OmpR damages the cell envelope. J Bacteriol 193:842-53
Wolfe, Alan J (2010) Physiologically relevant small phosphodonors link metabolism to signal transduction. Curr Opin Microbiol 13:204-9
Wolfe, Alan J (2010) Sighting the alien within: a new look at Bdellovibrio. J Bacteriol 192:6327-8

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