Global regulation of gene expression by ArlRS, a two-component signal transduction regulatory system of Staphylococcus aureus

Abstract

Staphylococcus aureus expresses various cell wall-associated and extracellular virulence factors, coordinately controlled by different two-component signal transduction systems and transcriptional regulators. In this study, we used microarray technology to identify the genes regulated by ArlR. The microarray data indicate that ArlR functions as a positive regulator and also as a negative repressor to directly and/or indirectly mediate the expression of at least 114 genes involved in different functions, including autolysis, cell division, growth, and pathogenesis.

FIG. 1.

Growth curve of the arlR mutant. The arlR mutant strain Sa316ko and parent strain WCUH29 were incubated in TSB at 37°C overnight with shaking; the cultures were inoculated in fresh TSB. The cell growth was monitored at 37°C by a measuring of the OD at 600 nm every 15 min with 1 min of mixing before each reading. These curves represent one of three reproducible experiments.

FIG. 2.

Schematic figure showing how the staphylococcal two-component signal transduction regulatory system, ArlRS, directly and/or indirectly modulates gene expression. →, positive regulation; ⊥, negative regulation.