Poster abstracts

Poster number 46 submitted by Kiley Dare

Expanding the physiological role of multiple peptide resistance factor in bacteria

Kiley E. Dare (Department of Microbiology, The Ohio State University), Herve Roy (Department of Microbiology, The Ohio State University), Bailey Dyer (Department of Microbiology, The Ohio State Univeristy), Michael Ibba (Department of Microbiology, The Ohio State University, Ohio State Biochemistry Program, Center for Microbial Interface Biology, Center for RNA Biology)

Abstract:
Multiple peptide resistance factor (MprF) is a protein that transfers amino acids from aminoacyl-tRNAs to phosphatidylglycerol (PG) in the cytoplasmic membrane. Aminoacylation of PG is a strategy utilized by bacteria to decrease the net negative charge of the cell envelope, thereby diminishing affinity for positively charged molecules and allowing for adaptation to environmental changes. Previous studies of MprF with specificity for the amino acid lysine have shown it to be an important virulence factor of Staphylococcus aureus, providing resistance to both host cationic antimicrobial peptides and therapeutic antibiotics. The physiological role of the highly diverse mprF homologs in other bacterial species remains largely unstudied. Examination of the physiological activity of MprF in Listeria monocytogenes and Bacillus subtilis by Biolog phenotypic microarray (PM) revealed phenotypes correlating with direct modulation of cell envelope charge and a new class of phenotypes that indicate a global effect on membrane properties. These two classes of phenotypes are consistent between the two organisms studied. Implicating MprF as a promising target for future development of antimicrobial therapies.

References:
1. Peschel, A., et al., Staphylococcus aureus resistance to human defensins and evasion of neutrophil killing via the novel virulence factor MprF is based on modification of membrane lipids with l-lysine. J Exp Med, 2001. 193(9): p. 1067-76.
2. Thedieck, K., et al., The MprF protein is required for lysinylation of phospholipids in listerial membranes and confers resistance to cationic antimicrobial peptides (CAMPs) on Listeria monocytogenes. Mol Microbiol, 2006. 62(5): p. 1325-39.
3. Staubitz, P. and A. Peschel, MprF-mediated lysinylation of phospholipids in Bacillus subtilis--protection against bacteriocins in terrestrial habitats? Microbiology, 2002. 148(Pt 11): p. 3331-2.
4.Roy, H., Tuning the properties of the bacterial membrane with aminoacylated phosphatidylglycerol. IUBMB Life, 2009. 61(10): p. 940-53.

Keywords: lipid modification, aminoacylphosphatidylglycerol synthase, tRNA