Bacterial murein hydrolases are essential for the normal assembly and processing of the bacterial cell wall during cell growth and division. Since these proteins also have the potential to cause autolysis, their expression must be tightly controlled. Recent studies in the applicant's laboratory have identified a putative two-component regulatory system in S. aureus (comprised of the LytS and LytR proteins) that has been shown to affect the expression of autolysis by controlling the level of murein hydrolase activity associated with the cell. Based on these preliminary studies, the present proposal concentrates on three different aspects of this system. First, the expression of genes that have been shown to be regulated by LytS and LytR will be carefully investigated using Northern blotting and primer extension studies, along with deletion mutagenesis of their operator/promoter regions. This will also include an analysis of possible environmental signals that feed into this system. Second, the components of signal transduction, mediated through LytS and LytR, will be studied by purifying the LytS and LytR proteins and then assaying the potential autophosphorylation and kinase activities common to the two-component regulatory system family of proteins. Any effects of this phosphorylation on DNA binding activity will be monitored. Third, other genes that are affected by the lyt locus will be identified and characterized. The results of the proposed studies will yield a great deal of information regarding the regulation of autolysis, providing new insight into the function of cell wall active antibiotics.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
First Independent Research Support & Transition (FIRST) Awards (R29)
Project #
5R29AI038901-04
Application #
6169302
Study Section
Bacteriology and Mycology Subcommittee 2 (BM)
Project Start
1997-07-01
Project End
2002-06-30
Budget Start
2000-07-01
Budget End
2001-06-30
Support Year
4
Fiscal Year
2000
Total Cost
$95,622
Indirect Cost
Name
University of Idaho
Department
Microbiology/Immun/Virology
Type
Schools of Earth Sciences/Natur
DUNS #
City
Moscow
State
ID
Country
United States
Zip Code
83844
Bayles, Kenneth W (2014) Bacterial programmed cell death: making sense of a paradox. Nat Rev Microbiol 12:63-9
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Chen, Fu; Liu, Xin-Ming; Rice, Kelly C et al. (2009) Tooth-binding micelles for dental caries prevention. Antimicrob Agents Chemother 53:4898-902
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Bayles, Kenneth W (2003) Are the molecular strategies that control apoptosis conserved in bacteria? Trends Microbiol 11:306-11
Rice, Kelly C; Firek, Brian A; Nelson, Jeremy B et al. (2003) The Staphylococcus aureus cidAB operon: evaluation of its role in regulation of murein hydrolase activity and penicillin tolerance. J Bacteriol 185:2635-43
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Fujimoto, D F; Brunskill, E W; Bayles, K W (2000) Analysis of genetic elements controlling Staphylococcus aureus lrgAB expression: potential role of DNA topology in SarA regulation. J Bacteriol 182:4822-8
Groicher, K H; Firek, B A; Fujimoto, D F et al. (2000) The Staphylococcus aureus lrgAB operon modulates murein hydrolase activity and penicillin tolerance. J Bacteriol 182:1794-801

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