title: Regulation of minD by oxyR in Neisseria gonorrhoeae.
abstract: In Neisseria gonorrhoeae, cytokinesis involves Escherichia coli homologues of minC, minD and minE which are encoded as part of a min operon. MinD, a 30 kD protein component of the MinC-MinD septum inhibitory complex, together with MinE, mediates cell division site selection. Gonococci mutated in minD display aberrant cytokinesis, abnormal morphology, defective microcolony formation and virulence. minD is 274 bp upstream of oxyR, another min operon gene in N. gonorrhoeae, which encodes a redox-responsive transcriptional regulator implicated in responses to oxidative stress. In this study, we aimed to examine the oxyR-mediated regulation of minD. We observed the cotranscription of oxyR with the minCDE gene cluster. The mutation of oxyR resulted in non-midline formation of the division septum, anomalous DNA segregation, and increased aggregation of bacterial cells. qRT-PCR and Western Blot analysis revealed upregulation of minD in an oxyR mutant as compared to its isogenic wild-type N. gonorrhoeae strain in stationary phase. Furthermore, the exposure to oxidative stress in the form of H2O2 increased MinD expression levels in wild-type N. gonorrhoeae. Using β-galactosidase activity-based promoter assays, we found that oxyR negatively regulates the promoter region (PminD) upstream of minD. Our results demonstrate the involvement of oxyR in cell division and minD expression in N. gonorrhoeae.
authors: Vaccine and Infectious Disease Organization, University of Saskatchewan, 120 Veterinary Road, Saskatoon, SK, Canada.
authors: Rajinder P
authors: RP
authors: Parti
authors: Monique A
authors: MA
authors: Horbay
authors: Mingmin
authors: M
authors: Liao
authors: Jo-Anne R
authors: JA
authors: Dillon
mesh_terms: D000251:Adenosine Triphosphatases / Q000096:biosynthesis*; D001426:Bacterial Proteins / Q000096:biosynthesis*; D015153:Blotting, Western; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D055786:Gene Knockout Techniques; D006861:Hydrogen Peroxide / Q000633:toxicity; D009344:Neisseria gonorrhoeae / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D018384:Oxidative Stress; D060888:Real-Time Polymerase Chain Reaction; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D012097:Repressor Proteins; D006861:Hydrogen Peroxide; D000251:Adenosine Triphosphatases; C439050:MinD protein, Neisseria gonorrhoeae