Characterization of bcsA mutations that bypass two distinct signaling requirements for Myxococcus xanthus development.
The BsgA protease is required for starvation-induced development in Myxococcus xanthus. Bypass suppressors of a bsgA mutant were isolated to identify genes that may encode additional components of BsgA protease-dependent regulation of development. Strain M951 was isolated following Tn5 mutagenesis of a bsgA mutant and was capable of forming fruiting bodies and viable spores in the absence of the BsgA protease. The Tn5Omega951 insertion was localized to a gene, bcsA, that encodes a protein that has significant amino acid similarity to a group of recently described flavin-containing monooxygenases involved in styrene catabolism. Mutations in bcsA bypassed the developmental requirements for both extracellular B and C signaling but did not bypass the requirement for A signaling. Bypass of the B-signaling requirement by the bcsA mutation was accompanied by restored expression of a subset of developmentally induced lacZ fusions to the BsgA protease-deficient strain. bcsA mutant cells developed considerably faster than wild-type cells at low cell density and altered transcriptional levels of a developmentally induced, cell-density-regulated gene (Omega4427), suggesting that the bcsA gene product may normally act to inhibit development in a cell-density-regulated fashion. Bypass of the requirements for both B and C signaling by bcsA mutations suggests a possible link between these two genetically, biochemically, and temporally distinct signaling requirements.
Department of Microbiology, University of Colorado Health Sciences Center, Denver, Colorado 80262, USA.
John K
JK
Cusick
Elizabeth
E
Hager
Ronald E
RE
Gill
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D003470:Culture Media; D004251:DNA Transposable Elements; D010450:Endopeptidases / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D009154:Mutation; D016941:Myxococcus xanthus / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D015398:Signal Transduction; D013171:Spores, Bacterial / Q000254:growth & development; D013489:Suppression, Genetic; D014157:Transcription Factors; D014158:Transcription, Genetic
D001426:Bacterial Proteins; D003470:Culture Media; D004251:DNA Transposable Elements; D014157:Transcription Factors; D010450:Endopeptidases; C082110:BsgA protein, Myxococcus xanthus