Regulation of arginine acquisition and virulence gene expression in the human pathogen Streptococcus pneumoniae by transcription regulators ArgR1 and AhrC.
J Biol Chem, 2011/12/30;286(52):44594-605.
Affiliations
PMID: 22084243DOI: 10.1074/jbc.M111.295832
Impact factor: 5.486
Abstract
In this study, we investigated for the first time the transcriptional response of the human pathogen Streptococcus pneumoniae to fluctuating concentrations of arginine, an essential amino acid for this bacterium. By means of DNA microarray analyses, several operons and genes were found, the expression of which was affected by the concentration of arginine in the medium. Five of the identified operons were demonstrated to be directly repressed in the presence of high arginine concentrations via the concerted action of the ArgR-type regulators ArgR1 and AhrC. These ArgR1/AhrC targets encompass the putative amino acid transport genes artPQ, abpA, abpB, and aapA; the arginine biosynthetic genes argGH; and the virulence genes aliB and lmB/adcAII-phtD encoding an oligopeptide-binding lipoprotein and cell surface Zn(2+)-scavenging units, respectively. In addition, the data indicate that three of the amino acid transport genes encode an arginine ATP-binding cassette transporter unit required for efficient growth during arginine limitation. Instead of regulating arginine biosynthetic and catabolic genes as has been reported for other Gram-positive bacteria, our findings suggest that the physiological function of ArgR1/AhrC in S. pneumoniae is to ensure optimal uptake of arginine from the surrounding milieu.
MeSH terms
Amino Acid Transport Systems; Arginine; Bacterial Proteins; Gene Expression Regulation, Bacterial; Humans; Oligonucleotide Array Sequence Analysis; Streptococcus pneumoniae; Transcription Factors; Virulence Factors
More resources
Full text:
Europe PubMed Central; PubMed Central
EndNote: Download