The YjbH Adaptor Protein Enhances Proteolysis of the Transcriptional Regulator Spx in Staphylococcus aureus
- 22 December 2011
- journal article
- Published by American Society for Microbiology in Journal of Bacteriology
- Vol. 194 (5), 1186-1194
- https://doi.org/10.1128/jb.06414-11
Abstract
Spx is a global regulator that is widespread among the low-G+C-content gram-positive bacteria. Spx has been extensively studied in Bacillus subtilis, where it acts as an activator and a repressor of transcription in response to disulfide stress. Under nonstress conditions, Spx is rapidly degraded by the ClpXP protease. This degradation is enhanced by the YjbH adaptor protein. Upon disulfide stress, the amount of Spx rapidly increases due to a decrease in degradation. In the opportunistic pathogen Staphylococcus aureus, Spx is a global regulator influencing growth, biofilm formation, and general stress protection, and cells lacking the spx gene exhibit poor growth also under nonstress conditions. To investigate the mechanism by which the activity of Spx is regulated, we identified a homolog in S. aureus of the B. subtilis yjbH gene. The gene encodes a protein that shows approximately 30% sequence identity to YjbH of B. subtilis. Heterologous expression of S. aureus yjbH in a B. subtilis yjbH mutant restored Spx to wild-type levels both under nonstress conditions and under conditions of disulfide stress. From these studies, we conclude that the two YjbH homologues have a conserved physiological function. Accordingly, inactivation of yjbH in S. aureus increased the level of Spx protein and transcription of the Spx-regulated gene trxB. Notably, the yjbH mutant exhibited reduced growth and increased pigmentation, and both phenotypes were reversed by complementation of the yjbH gene.Keywords
This publication has 41 references indexed in Scilit:
- New Role of the Disulfide Stress Effector YjbH in β-Lactam Susceptibility of Staphylococcus aureusAntimicrobial Agents and Chemotherapy, 2011
- YjbH-Enhanced Proteolysis of Spx by ClpXP in Bacillus subtilis Is Inhibited by the Small Protein YirB (YuzO)Journal of Bacteriology, 2011
- Two Spx Proteins Modulate Stress Tolerance, Survival, and Virulence inStreptococcus mutansJournal of Bacteriology, 2010
- Development of amariner-Based Transposon and Identification ofListeria monocytogenesDeterminants, Including the Peptidyl-Prolyl Isomerase PrsA2, That Contribute to Its Hemolytic PhenotypeJournal of Bacteriology, 2009
- Improved single-copy integration vectors for Staphylococcus aureusJournal of Microbiological Methods, 2007
- Mechanisms of Adaptation to Nitrosative Stress inBacillus subtilisJournal of Bacteriology, 2007
- ATP-dependent proteases of bacteria: recognition logic and operating principlesTrends in Biochemical Sciences, 2006
- Investigations into σ B -Modulated Regulatory Pathways Governing Extracellular Virulence Determinant Production in Staphylococcus aureusJournal of Bacteriology, 2006
- Staphylococcus aureus Mutants with Increased Lysostaphin ResistanceJournal of Bacteriology, 2006
- Spx Is a Global Effector Impacting Stress Tolerance and Biofilm Formation inStaphylococcus aureusJournal of Bacteriology, 2006