RNAIII of the Staphylococcus aureus agr system activates global regulator MgrA by stabilizing mRNA.
RNAIII, the effector of the agr quorum-sensing system, plays a key role in virulence gene regulation in Staphylococcus aureus, but how RNAIII transcriptionally regulates its downstream genes is not completely understood. Here, we show that RNAIII stabilizes mgrA mRNA, thereby increasing the production of MgrA, a global transcriptional regulator that affects the expression of many genes. The mgrA gene is transcribed from two promoters, P1 and P2, to produce two mRNA transcripts with long 5' UTR. Two adjacent regions of the mgrA mRNA UTR transcribed from the upstream P2 promoter, but not the P1 promoter, form a stable complex with two regions of RNAIII near the 5' and 3' ends. We further demonstrate that the interaction has several biological effects. We propose that MgrA can serve as an intermediary regulator through which agr exerts its regulatory function.
Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, AR 72205.
Ravi Kr
RK
Gupta
Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, AR 72205.
Thanh T
TT
Luong
Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, AR 72205 clee2@uams.edu.
Chia Y
CY
Lee
D020029:Base Pairing; D001483:Base Sequence; D015153:Blotting, Western; D024202:Electrophoretic Mobility Shift Assay; D040461:Gene Components; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics*; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic / Q000235:genetics; D053038:Quorum Sensing / Q000235:genetics*; D012329:RNA, Bacterial / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction; D050436:Regulatory Elements, Transcriptional / Q000235:genetics*; D013211:Staphylococcus aureus / Q000201:enzymology*
D012329:RNA, Bacterial; C096035:RNAIII, Staphylococcus aureus
MgrA; RNAIII; Staphylococcus aureus; virulence regulation