TodK, a putative histidine protein kinase, regulates timing of fruiting body morphogenesis in Myxococcus xanthus.
In response to starvation, Myxococcus xanthus initiates a developmental program that results in the formation of spore-filled multicellular fruiting bodies. Fruiting body formation depends on the temporal and spatial coordination of aggregation and sporulation. These two processes are induced by the cell surface-associated C signal, with aggregation being induced after 6 h and sporulation being induced once cells have completed the aggregation process. We report the identification of TodK, a putative histidine protein kinase of two-component regulatory systems that is important for the correct timing of aggregation and sporulation. Loss of TodK function results in early aggregation and early, as well as increased levels of, sporulation. Transcription of todK decreases 10-fold in response to starvation independently of the stringent response. Loss of TodK function specifically results in increased expression of a subset of C-signal-dependent genes. Accelerated development in a todK mutant depends on the known components in the C-signal transduction pathway. TodK is not important for synthesis of the C signal. From these results we suggest that TodK is part of a signal transduction system which converges on the C-signal transduction pathway to negatively regulate aggregation, sporulation, and the expression of a subset of C-signal-dependent genes. TodK and the SdeK histidine protein kinase, which is part of a signal transduction system that converges on the C-signal transduction pathway to stimulate aggregation, sporulation, and C-signal-dependent gene expression, act in independent genetic pathways. We suggest that the signal transduction pathways defined by TodK and SdeK act in concert with the C-signal transduction pathway to control the timing of aggregation and sporulation.
Rasmussen
Anders A
AA
Department of Biochemistry and Molecular Biology, University of Southern Denmark Odense, 5230 Odense M, Denmark.
Søgaard-Andersen
Lotte
L
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D003001:Cloning, Molecular; D015964:Gene Expression Regulation, Bacterial; D000071677:Histidine Kinase; D008969:Molecular Sequence Data; D009024:Morphogenesis; D009154:Mutation; D016941:Myxococcus xanthus / Q000201:enzymology / Q000235:genetics / Q000254:growth & development*; D011494:Protein Kinases / Q000235:genetics* / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D013171:Spores, Bacterial / Q000502:physiology; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
D001426:Bacterial Proteins; C104848:FruA protein, Myxococcus xanthus; C065626:FrzCD protein, Myxococcus xanthus; C114349:SdeK protein, Myxococcus xanthus; D014157:Transcription Factors; D011494:Protein Kinases; D000071677:Histidine Kinase