A fundamental feature of a living system is its integrated network of biochemical pathways that respond to endogenous and environmental stresses. In humans, there is a strong connection between metabolic network dysfunction and disease. Metabolic strategies are conserved across biology, and insights obtained from model organisms provide the means to advance our understanding of general metabolic paradigms, which can often be extrapolated to higher organisms including humans. The long-term goal of the PI's research is to understand the robustness and redundancy of the metabolic network, and to define metabolic components and the processes they participate in. Knowledge of metabolic processes and a mechanistic understanding of the function of unknown proteins is critical to efforts aimed at treating metabolic diseases, and to efforts targeting metabolism for rational drug design, synthetic biology, microbiome research, etc. The goal of the work proposed herein is to advance our understanding of the metabolic stress caused by the 2-aminoacrylate, an obligate intermediate in central metabolic reactions, and the protein that controls it, RidA. Further, this study focuses on the highly conserved Rid protein family, of which RidA is the founding member. In the current proposal we will: i) describe additional, distinct mechanisms that have evolved to deal with similar stress; ii) explore the breadth of 2-aminoacrylate stress and how different organisms handle it, and iii) define the molecular mechanism and cellular role of additional Rid proteins. The goals of this proposal will be accomplished through a combination of chemical, biochemical, molecular genetic, bioinformatics and global approaches. The work here is motivated by our desire to understand the metabolic stress generated by the production of reactive metabolites during growth, how it can damage cellular components if it is not neutralized, and discovering the role of additional members of the broadly conserved protein family that includes RidA.

Public Health Relevance

Metabolism describes the processes required for life in all biological systems. Understanding metabolism is essential for biomedical progress including targeting metabolism for rational drug design and/or production of small molecules. Our work contributes new, fundamental knowledge about the nature and behavior of living systems by defining the biochemical function and metabolic role for a family of proteins that is conserved from bacteria to man, and whose function is unknown.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
2R01GM095837-10
Application #
10118485
Study Section
Prokaryotic Cell and Molecular Biology Study Section (PCMB)
Program Officer
Barski, Oleg
Project Start
2011-09-01
Project End
2024-08-31
Budget Start
2020-09-20
Budget End
2021-08-31
Support Year
10
Fiscal Year
2020
Total Cost
Indirect Cost
Name
University of Georgia
Department
Microbiology/Immun/Virology
Type
Schools of Arts and Sciences
DUNS #
004315578
City
Athens
State
GA
Country
United States
Zip Code
30602
Ernst, Dustin C; Borchert, Andrew J; Downs, Diana M (2018) Perturbation of the metabolic network in Salmonella enterica reveals cross-talk between coenzyme A and thiamine pathways. PLoS One 13:e0197703
Hodge-Hanson, Kelsey M; Zoino, Allison; Downs, Diana M (2018) Expression of Pyridoxal 5'-Phosphate-Independent Racemases Can Reduce 2-Aminoacrylate Stress in Salmonella enterica. J Bacteriol 200:
Ernst, Dustin C; Christopherson, Melissa R; Downs, Diana M (2018) Increased Activity of Cystathionine ?-Lyase Suppresses 2-Aminoacrylate Stress in Salmonella enterica. J Bacteriol 200:
Ernst, Dustin C; Downs, Diana M (2018) Mmf1p Couples Amino Acid Metabolism to Mitochondrial DNA Maintenance in Saccharomyces cerevisiae. MBio 9:
Irons, Jessica; Hodge-Hanson, Kelsey M; Downs, Diana M (2018) PA5339, a RidA Homolog, Is Required for Full Growth in Pseudomonas aeruginosa. J Bacteriol 200:
Borchert, Andrew J; Downs, Diana M (2017) Endogenously generated 2-aminoacrylate inhibits motility in Salmonella enterica. Sci Rep 7:12971
Borchert, Andrew J; Downs, Diana M (2017) The Response to 2-Aminoacrylate Differs in Escherichia coli and Salmonella enterica, despite Shared Metabolic Components. J Bacteriol 199:
Hodge-Hanson, Kelsey M; Downs, Diana M (2017) Members of the Rid protein family have broad imine deaminase activity and can accelerate the Pseudomonas aeruginosa D-arginine dehydrogenase (DauA) reaction in vitro. PLoS One 12:e0185544
Ernst, Dustin C; Downs, Diana M (2016) 2-Aminoacrylate Stress Induces a Context-Dependent Glycine Requirement in ridA Strains of Salmonella enterica. J Bacteriol 198:536-43
ElRamlawy, Kareem Gamal; Fujimura, Takashi; Baba, Koji et al. (2016) Der f 34, a Novel Major House Dust Mite Allergen Belonging to a Highly Conserved Rid/YjgF/YER057c/UK114 Family of Imine Deaminases. J Biol Chem 291:21607-21615

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