Cell cycle-dependent degradation of a flagellar motor component requires a novel-type response regulator
Cell cycle-dependent degradation of a flagellar motor component requires a novel-type response regulator
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DOI：
10.1046/j.1365-2958.1999.01358.x
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发表时间：
1999-04-01
影响因子：
3.6
通讯作者：
Jenal, U
中科院分区：
文献类型：
--
作者：
Aldridge, P;Jenal, U
每个新月柄杆菌细胞的极经历作为细胞周期的函数的形态发育。一个单一的鞭毛组装在一个极不对称的细胞分裂过程中，后来弹出，并取代了新合成的柄时，能动的蜂群后代分化成一个无柄柄的细胞。鞭毛的去除过程中的swarmer-to-stalked细胞过渡与FliF鞭毛锚蛋白的降解相一致。我们在这里报告说，FliF的细胞周期依赖性营业额不需要鞭毛本身的结构组成部分，认为这是导致鞭毛弹射的初始事件。极性发展突变体，pleD的分析表明，pleD基因是必需的有效去除FliF和弹射的鞭毛结构在swarmer-to-stalked细胞过渡。FliF降解的PleD要求也不依赖于鞭毛结构的任何部分的存在。此外，当PleD不存在时，只有25%的细胞能够在细胞分化期间合成茎。pleD基因编码具有新的C-末端调节结构域的反应调节因子家族的成员。突变分析证实，PleD C-末端结构域中的高度保守基序对于促进细胞分化期间的FliF降解和茎生物发生是必不可少的。因此，C需要通过PleD的C-末端结构域的信号传导。新月形极地发育。第二个基因，fliL，被证明是所需的FliF的有效营业额，但不是茎生物发生。PleD和FliL在C. crescentus极地发育进行了讨论。
The poles of each Caulobacter crescentus cell undergo morphological development as a function of the cell cycle. A single flagellum assembled at one pole during the asymmetric cell division is later ejected and replaced by a newly synthesized stalk when the motile swarmer progeny differentiates into a sessile stalked cell. The removal of the flagellum during the swarmer-to-stalked cell transition coincides with the degradation of the FliF flagellar anchor protein. We report here that the cell cycle-dependent turnover of FliF does not require the structural components of the flagellum itself, arguing that it is the initial event leading to the ejection of the flagellum. Analysis of a polar development mutant, pleD, revealed that the pleD gene was required for efficient removal of FliF and for ejection of the flagellar structure during the swarmer-to-stalked cell transition. The PleD requirement for FliF degradation was also not dependent on the presence of any part of the flagellar structure. In addition, only 25% of the cells were able to synthesize a stalk during cell differentiation when PleD was absent. The pleD gene codes for a member of the response regulator family with a novel C-terminal regulatory domain. Mutational analysis confirmed that a highly conserved motif in the PleD C-terminal domain is essential to promote both FliF degradation and stalk biogenesis during cell differentiation. Signalling through the C-terminal domain of PleD is thus required for C. crescentus polar development. A second gene, fliL, was shown to be required for efficient turnover of FliF, but not for stalk biogenesis. The possible roles of PleD and FliL in C. crescentus polar development are discussed.