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Title
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An essential single domain response regulator required for normal cell division and differentiation in Caulobacter crescentus.
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Authors
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G.B.Hecht,
T.Lane,
N.Ohta,
J.M.Sommer,
A.Newton.
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Ref.
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Embo J, 1995,
14,
3915-3924.
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PubMed id
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Abstract
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Signal transduction pathways mediated by sensor histidine kinases and cognate
response regulators control a variety of physiological processes in response to
environmental conditions. Here we show that in Caulobacter crescentus these
systems also play essential roles in the regulation of polar morphogenesis and
cell division. Previous studies have implicated histidine kinase genes pleC and
divJ in the regulation of these developmental events. We now report that divK
encodes an essential, cell cycle-regulated homolog of the CheY/Spo0F subfamily
and present evidence that this protein is a cognate response regulator of the
histidine kinase PleC. The purified kinase domain of PleC, like that of DivJ,
can serve as an efficient phosphodonor to DivK and as a phospho-DivK
phosphatase. Based on these and earlier genetic results we propose that PleC and
DivK are members of a signal transduction pathway that couples motility and
stalk formation to completion of a late cell division cycle event. Gene
disruption experiments and the filamentous phenotype of the conditional divK341
mutant reveal that DivK also functions in an essential signal transduction
pathway required for cell division, apparently in response to another histidine
kinase. We suggest that phosphotransfer mediated by these two-component signal
transduction systems may represent a general mechanism regulating cell
differentiation and cell division in response to successive cell cycle
checkpoints.
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