The bacterial Sec system is required for the organization and function of the MreB cytoskeleton.
The bacterial Sec system is required for the organization and function of the MreB cytoskeleton.
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DOI：
10.1371/journal.pgen.1007017
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发表时间：
2017-09
期刊：
影响因子：
4.5
通讯作者：
Amster-Choder O
中科院分区：
文献类型：
--
作者：
Govindarajan S;Amster-Choder O
Sec系统负责所有细胞中的蛋白质插入、易位和跨膜分泌。细菌肌动蛋白同源物MreB控制各种过程，包括细胞壁合成，膜组织和极性建立。在这里，我们表明，这两个系统在遗传上相互作用，并且Sec系统的组成部分，特别是SecA马达蛋白，对于E. MreB在Sec受损细胞的不规则位点的积累证明了这一点。SecA缺陷细胞中的MreB错误定位显著影响MreB协调过程，如细胞壁合成，并诱导形成富含高流动性结构域的膜内陷。此外，在secA突变细胞中，MreB不会被募集到FtsZ环中，从而导致分裂停滞和细胞增殖。我们的研究结果表明，所有这些故障是由于不存在SecA的情况下，MreB不正确地靶向膜。因此，当我们通过将RodZ，MreB膜锚定物融合到SecA独立的整合膜蛋白并过量产生它来重新路由RodZ时，MreB定位被恢复，细胞分裂中的缺陷被纠正。值得注意的是，RodZ部分没有正确插入膜中，强烈表明它仅用作将MreB放置在细胞周围的诱饵。最后，我们表明，MreB本地化依赖于SecA在C中也。crescentus，表明MreB的调节Sec系统是保守的细菌。总之，我们的数据表明，分泌系统在决定细菌细胞骨架系统的组织和功能方面起着重要作用。细菌细胞具有复杂的空间组织，影响许多重要过程，这是一个相对较新的概念，因此，基本机制在很大程度上是未知的。在真核生物和原核生物中，一般分泌系统和细胞骨架是中心系统，已知每个都组织与某些细胞结构域相关的功能。虽然Sec系统在膜蛋白移位和分泌中的作用已被大量探索，但对其在内细胞组织中的作用知之甚少。我们发现，SEC系统是重要的本地化模式和功能的细菌细胞骨架系统，控制细胞的形状，细胞分裂和极性。我们的研究结果突出了Sec系统作为控制膜两侧细胞功能的中央协调器。
The Sec system is responsible for protein insertion, translocation and secretion across membranes in all cells. The bacterial actin homolog MreB controls various processes, including cell wall synthesis, membrane organization and polarity establishment. Here we show that the two systems genetically interact and that components of the Sec system, especially the SecA motor protein, are essential for spatiotemporal organization of MreB in E. coli, as evidenced by the accumulation of MreB at irregular sites in Sec-impaired cells. MreB mislocalization in SecA-defective cells significantly affects MreB-coordinated processes, such as cell wall synthesis, and induce formation of membrane invaginations enriched in high fluidity domains. Additionally, MreB is not recruited to the FtsZ ring in secA mutant cells, contributing to division arrest and cell filamentation. Our results show that all these faults are due to improper targeting of MreB to the membrane in the absence of SecA. Thus, when we reroute RodZ, MreB membrane-anchor, by fusing it to a SecA-independent integral membrane protein and overproducing it, MreB localization is restored and the defect in cell division is corrected. Notably, the RodZ moiety is not properly inserted into the membrane, strongly suggesting that it only serves as a bait for placing MreB around the cell circumference. Finally, we show that MreB localization depends on SecA also in C. crescentus, suggesting that regulation of MreB by the Sec system is conserved in bacteria. Taken together, our data reveal that the secretion system plays an important role in determining the organization and functioning of the cytoskeletal system in bacteria. The notion that bacterial cells have intricate spatial organization, which affects many vital processes, is relatively new and, hence, the underlying mechanisms are largely unknown. The general secretion system and the cytoskeleton are central systems, each known to organize functions associated with certain cellular domains, in both eukaryotes and prokaryotes. While the role of the Sec system in membrane protein translocation and secretion has been largely explored, not much in known about its role in inner cell organization. We show that the Sec system is important for the localization pattern and functionality of the bacterial cytoskeletal system, which controls cell shape, cell division and polarity. Our findings highlight the Sec system as a central coordinator that controls cellular functions on both sides of the membrane.
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DOI：
10.1073/pnas.0402638101
发表时间：
2004-06-08
影响因子：
11.1
作者：
Gitai, Z;Dye, N;Shapiro, L
通讯作者：
Shapiro, L
影响因子：
3.2
作者：
Dinh, Thuy;Bernhardt, Thomas G.
通讯作者：
Bernhardt, Thomas G.
影响因子：
11.4
作者：
Bendezu, Felipe O.;Hale, Cynthia A.;de Boer, Piet A. J.
通讯作者：
de Boer, Piet A. J.
DOI：
10.1016/0005-2736(89)90418-5
发表时间：
1989-11-03
期刊：
BIOCHIMICA ET BIOPHYSICA ACTA
影响因子：
--
作者：
DECOCK, H;MEELDIJK, J;TOMMASSEN, J
通讯作者：
TOMMASSEN, J
影响因子：
5.2
作者：
Halbedel, Sven;Kawai, Maki;Hamoen, Leendert W.
通讯作者：
Hamoen, Leendert W.