Elongation Factor P (EF-P) is a universally conserved post-translationally modified protein that relieves ribosomal pausing at polyproline motifs by binding to the ribosome and entropically stimulating peptide bond formation. In all examples characterized to date EF-P and its homologs require post-translational modification to be functional. The function of EF-P modifications and the mechanism by which modifications would improve translation efficiency is unclear. Mutations in bacterial genes encoding EF-P (efp) or the corresponding modification pathways are highly pleiotropic, leading to a variety of detrimental phenotypes including slowed growth, loss of motility, attenuated virulence and hypersensitivity to antibiotics. Preliminary characterization of post-translational modification of Bacillus subtilis EF-P, which requires 5-aminopentanol addition for activity, challenges the notion that EF-P functions solely to maintain basic cellular function. In B. subtilis the ratio of modified to unmodified EF-P varies with growth phase, and neither deletion of EF-P nor removal of the modification impair vegetative growth, but instead specifically impair motility development. We hypothesize, based on the chemical diversity of permissive post-translational modification groups, that EF-P modification is regulatory. B. subtilis is an ideal model organism to explore this hypothesis as defects in either EF-P or EF-P modification impair swarming motility, a powerful phenotype for unbiased genetic selection. The objectives of this proposal are to uncover the structural and functional diversity of EF-P by investigating the different mechanisms by which this conserved, ubiquitous, translation factor functions during protein synthesis. Specifically, we will determine how EF-P acts as a cellular differentiation-specific translation factor and investigate the mechanism of translational control by EF-P.

Public Health Relevance

Infections with pathogenic isolates of Salmonella, E. coli, Pseudomonas sp. and Bacillus sp. can all lead to infectious diseases with potentially fatal sequelae. EF-P proteins contribute to the pathogenicity of the causative agents of these and other diseases by controlling the translation of proteins critical for modulating antibiotic resistance, motility and other traits that play key roles in establishing virulence. The proposed studies will define how EF-P functions in bacterial translational control, and may provide indicators as to whether corresponding pathways, which are unique to bacteria, can be used as targets for anti-infective agents. eIF5A, the eukaryotic homolog of EF-P, requires modification with the amino acid hypusine to function in translation and has been implicated in promoting translation of mRNAs encoding proteins involved in cell cycle progression and inflammation, linking this factor to both cancer and diabetes. The proposed investigations on how EF-P functions in protein synthesis and translational control will provide new insights into the roles EF-P, and indirectly eIF5a, play in regulating gene expression.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM065183-15
Application #
9557051
Study Section
Special Emphasis Panel (ZRG1)
Program Officer
Barski, Oleg
Project Start
2003-01-01
Project End
2021-05-31
Budget Start
2018-06-01
Budget End
2019-05-31
Support Year
15
Fiscal Year
2018
Total Cost
Indirect Cost
Name
Ohio State University
Department
Microbiology/Immun/Virology
Type
Schools of Arts and Sciences
DUNS #
832127323
City
Columbus
State
OH
Country
United States
Zip Code
43210
Rojas, JoaquĆ­n; Castillo, Gabriel; Leiva, Lorenzo Eugenio et al. (2018) Codon usage revisited: Lack of correlation between codon usage and the number of tRNA genes in enterobacteria. Biochem Biophys Res Commun 502:450-455
Tollerson 2nd, Rodney; Witzky, Anne; Ibba, Michael (2018) Elongation factor P is required to maintain proteome homeostasis at high growth rate. Proc Natl Acad Sci U S A 115:11072-11077
Wang, Siyao; Corcilius, Leo; Sharp, Phillip P et al. (2017) Synthesis of rhamnosylated arginine glycopeptides and determination of the glycosidic linkage in bacterial elongation factor P. Chem Sci 8:2296-2302
Hummels, Katherine R; Witzky, Anne; Rajkovic, Andrei et al. (2017) Carbonyl reduction by YmfI in Bacillus subtilis prevents accumulation of an inhibitory EF-P modification state. Mol Microbiol 106:236-251
Tollerson 2nd, Rodney; Witzky, Anne; Ibba, Michael (2017) Elongation Factor P Interactions with the Ribosome Are Independent of Pausing. MBio 8:
Elgamal, Sara; Artsimovitch, Irina; Ibba, Michael (2016) Maintenance of Transcription-Translation Coupling by Elongation Factor P. MBio 7:
Katz, Assaf; Elgamal, Sara; Rajkovic, Andrei et al. (2016) Non-canonical roles of tRNAs and tRNA mimics in bacterial cell biology. Mol Microbiol 101:545-58
Rajkovic, Andrei; Hummels, Katherine R; Witzky, Anne et al. (2016) Translation Control of Swarming Proficiency in Bacillus subtilis by 5-Amino-pentanolylated Elongation Factor P. J Biol Chem 291:10976-85
Rajkovic, Andrei; Erickson, Sarah; Witzky, Anne et al. (2015) Cyclic Rhamnosylated Elongation Factor P Establishes Antibiotic Resistance in Pseudomonas aeruginosa. MBio 6:e00823
Shepherd, Jennifer; Ibba, Michael (2015) Bacterial transfer RNAs. FEMS Microbiol Rev 39:280-300

Showing the most recent 10 out of 61 publications