FlgN is required for flagellum-based motility by Bacillus subtilis.
FlgN is required for flagellum-based motility by Bacillus subtilis.
复制标题
DOI：
10.1128/jb.01599-14
复制
发表时间：
2014-06
影响因子：
3.2
通讯作者：
Stanley-Wall NR
中科院分区：
文献类型：
--
作者：
Cairns LS;Marlow VL;Kiley TB;Birchall C;Ostrowski A;Aldridge PD;Stanley-Wall NR
细菌鞭毛的组装受到精密的控制。鞭毛生物合成是由一个专门的III型分泌系统，允许出口的蛋白质从细胞质的新生结构。枯草芽孢杆菌调节鞭毛组装使用保守和物种特异性机制。在这里，我们表明，YvyG是必不可少的鞭毛丝组装。我们将YvyG定义为沙门氏菌血清型鼠伤寒III型分泌系统伴侣FlgN的直系同源物，FlgN是输出钩丝连接蛋白FlgK和FlgL所需的。flgN（yvyG）的缺失导致非运动表型，其可归因于hag翻译的减少和完全缺乏细丝聚合。分析表明，flgK-flgL双突变菌株表型模仿flgN的缺失，并且flgK-flgL的过表达不能补充ΔflgN菌株的运动缺陷。此外，在以往的工作表明，FlgN的磷酸化改变其亚细胞定位，我们表明，所确定的酪氨酸和精氨酸FlgN磷酸化位点的突变对运动没有影响。这些数据强调，鞭毛生物合成差异调节B。枯草杆菌从经典研究的革兰氏阴性鞭毛系统和问题的生物相关性的一些翻译后修饰确定的全球蛋白质组学方法。
The assembly of the bacterial flagellum is exquisitely controlled. Flagellar biosynthesis is underpinned by a specialized type III secretion system that allows export of proteins from the cytoplasm to the nascent structure. Bacillus subtilis regulates flagellar assembly using both conserved and species-specific mechanisms. Here, we show that YvyG is essential for flagellar filament assembly. We define YvyG as an orthologue of the Salmonella enterica serovar Typhimurium type III secretion system chaperone, FlgN, which is required for the export of the hook-filament junction proteins, FlgK and FlgL. Deletion of flgN (yvyG) results in a nonmotile phenotype that is attributable to a decrease in hag translation and a complete lack of filament polymerization. Analyses indicate that a flgK-flgL double mutant strain phenocopies deletion of flgN and that overexpression of flgK-flgL cannot complement the motility defect of a ΔflgN strain. Furthermore, in contrast to previous work suggesting that phosphorylation of FlgN alters its subcellular localization, we show that mutation of the identified tyrosine and arginine FlgN phosphorylation sites has no effect on motility. These data emphasize that flagellar biosynthesis is differentially regulated in B. subtilis from classically studied Gram-negative flagellar systems and questions the biological relevance of some posttranslational modifications identified by global proteomic approaches.