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author:("Shi, wenchuan")
1.  Type IV Pilus-Dependent Motility and Its Possible Role in Bacterial Pathogenesis  
Infection and Immunity  2002;70(1):1-4.
PMCID: PMC127603  PMID: 11748156
2.  Analyses of mrp Genes during Myxococcus xanthus Development 
Journal of Bacteriology  2001;183(23):6733-6739.
Myxococcus xanthus is a gram-negative soil bacterium that undergoes development under starvation conditions. Our previous study identified a new genetic locus, mrp, which is required for both fruiting body formation and sporulation. The locus encodes two transcripts: mrpAB, which consists of a histidine kinase and an NtrC-like response regulator, and mrpC, a cyclic AMP receptor protein family transcription activator. In this study, we used genetic and biochemical analyses to investigate the possible interactions between the mrp genes and other known developmental genes and events. These studies show that the mrp genes possibly function after A-signaling and (p)ppGpp but before C-signaling and that they regulate various early and late developmental genes and events.
PMCID: PMC95511  PMID: 11698359
3.  Genetic Studies of mrp, a Locus Essential for Cellular Aggregation and Sporulation of Myxococcus xanthus 
Journal of Bacteriology  2001;183(16):4786-4795.
Under starvation conditions, Myxococcus xanthus undergoes a complex developmental process which includes cellular aggregation and sporulation. A transposon insertion mutant (the Tn5-Ω280 mutant) with defects in both aggregation and sporulation was analyzed in this study. The Tn5-Ω280 mutant was found to have a disrupted NtrC-like response regulator designated Myxococcus regulatory protein B (mrpB). Further sequencing analyses revealed a histidine kinase homolog (mrpA) immediately upstream of mrpB and a cyclic AMP receptor protein-like transcriptional regulator (mrpC) downstream of mrpB. In-frame deletion analyses revealed that both the mrpB and mrpC genes were required for cellular aggregation and sporulation but that only mrpA was required for sporulation only. Site-specific mutagenesis of the putative phosphorylation site of MrpB, D58, showed that a D58A mutation caused defects in both aggregation and sporulation but that a D58E mutation resulted in only a sporulation defect. Further genetic and molecular analyses with reporter genes and reverse transcription-PCR indicated that mrpA and mrpB are cotranscribed but that mrpC is transcribed independently and that all of these genes are developmentally regulated. In addition, MrpB is essential for transcription of mrpC and MrpC regulates its own transcription. These data indicate that Mrp proteins are important components required for M. xanthus development. The complicated interaction between Mrp proteins may play an important role in regulating developmental gene expression in M. xanthus.
PMCID: PMC99533  PMID: 11466282

Results 1-3 (3)