Roles of histidine protein kinase PleC in Caulobacter crescentus motility and chemotaxis
Roles of histidine protein kinase PleC in Caulobacter crescentus motility and chemotaxis
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DOI：
10.1128/jb.179.18.5849-5853.1997
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发表时间：
1997-09-01
影响因子：
3.2
通讯作者：
Newton, A
中科院分区：
文献类型：
--
作者：
Burton, GJ;Hecht, GB;Newton, A
新月桂杆菌组氨酸激酶基因Plec和divJ分别参与了细胞形态发生和细胞分裂的调控，Plec突变也增强了divJ突变的细胞分裂表型。为了研究Plec激酶在运动和细胞周期调节中的作用，我们对具有温度敏感运动(Mot(-))表型的divJ332等位基因进行了假逆转分析。所有具有37℃Mot(+)表型和24℃软琼脂冷敏群体表型的冷敏感假逆转株都含有基因外抑制基因，这些基因外抑制基因是Plec的零突变。然而，在不允许的温度下，逆转株显示了趋化性的冷敏感缺陷(Che(-))，而不是细胞分裂缺陷。此外，突变的细胞还具有超运动性，这一表型以前只与反应调节基因pled的突变有关，这些突变阻断了运动性的丧失。我们还发现plD301/pled(+)二倍体抑制了plc突变体的mot-缺陷，并导致了类似的、超活动的、冷敏感的Che表型。这些结果暗示了由plc-divk和divJ-red介导的信号转导途径在趋化和运动的调节中。我们对这些发现进行了讨论，并观察到虽然plEC激酶在细胞分裂中并不起到不可或缺的作用。Plec的一个温度敏感等位基因(PleC319)在严酷的生长条件下严重降低了生命力。
The Caulobacter crescentus histidine kinase genes pleC and divJ have been implicated in the regulation of polar morphogenesis and cell division, respectively, Mutations in pleC also potentiate the cell division phenotype of divJ mutations. To investigate the involvement of the PleC kinase in motility and cell cycle regulation, we carried out a pseudoreversion analysis of the divJ332 allele, which confers a temperature-sensitive motility (Mot(-)) phenotype. All cold-sensitive pseudorevertants with a Mot(+) phenotype at 37 degrees C and a cold-sensitive swarm phenotype in soft agar at 24 degrees C contained extragenic suppressors that were null mutations mapping to pleC. Instead of a cell division defect at the nonpermissive temperature, however, revertants displayed a cold-sensitive defect in chemotaxis (Che(-)). In addition, the mutant cells were also supermotile, a phenotype previously associated only with mutations in the response regulator gene pleD that block the loss of motility, We also found that the Mot-defect of pleC mutants is suppressed by a pleD301/pleD(+) merodiploid and results in a similar, supermotile, cold-sensitive Che-phenotype, These results implicate signal transduction pathways mediated by PleC-DivK and DivJ-PleD in the regulation of chemotaxis as well as motility, We discuss these findings and the observation that although the PleC kinase does not play an indispensable role in cell division, a temperature-sensitive allele of pleC (pleC319) has severely reduced viability under stringent growth conditions.