The cell shape proteins MreB and MreC control cell morphogenesis by positioning cell wall synthetic complexes
The cell shape proteins MreB and MreC control cell morphogenesis by positioning cell wall synthetic complexes
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DOI：
10.1111/j.1365-2958.2007.05910.x
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发表时间：
2007-10-01
影响因子：
3.6
通讯作者：
Gober, James W.
中科院分区：
文献类型：
--
作者：
Divakaruni, Arun V.;Baida, Cyril;Gober, James W.
细菌肌动蛋白同源物MreB被认为与MreC一起在空间上协调细胞形态发生，MreC是一种在周质空间内包裹细胞外部的蛋白质。在新月柄杆菌中，MreC与青霉素结合蛋白（PBP）物理结合，后者催化细胞内合成的前体插入肽聚糖细胞壁。在这里，我们表明，MreC是必需的肽聚糖合成全酶在周质和MreB指导定位的肽聚糖前体合成蛋白质在胞质中的组件的空间组织。此外，荧光万古霉素（Van-FL）标记显示，细菌细胞骨架蛋白MreB和FtsZ，以及MreC和RodA，肽聚糖合成活性所需的。MreB和FtsZ被认为是所需的极柄的形态发生。需要FtsZ的细胞周期调节的肽聚糖合成的爆发，在细胞周期的早期，导致合成的交叉带结构，而MreB的延长的柄。因此，细菌细胞骨架和细胞形状决定蛋白如MreC协同作用以协调细胞壁合成复合物的定位，从而产生空间协调和有效的肽聚糖合成活性。
MreB, the bacterial actin homologue, is thought to function in spatially co-ordinating cell morphogenesis in conjunction with MreC, a protein that wraps around the outside of the cell within the periplasmic space. In Caulobacter crescentus, MreC physically associates with penicillin-binding proteins (PBPs) which catalyse the insertion of intracellularly synthesized precursors into the peptidoglycan cell wall. Here we show that MreC is required for the spatial organization of components of the peptidoglycan-synthesizing holoenzyme in the periplasm and MreB directs the localization of a peptidoglycan precursor synthesis protein in the cytosol. Additionally, fluorescent vancomycin (Van-FL) labelling revealed that the bacterial cytoskeletal proteins MreB and FtsZ, as well as MreC and RodA, were required for peptidoglycan synthetic activity. MreB and FtsZ were found to be required for morphogenesis of the polar stalk. FtsZ was required for a cell cycle-regulated burst of peptidoglycan synthesis early in the cell cycle resulting in the synthesis of cross-band structures, whereas MreB was required for lengthening of the stalk. Thus, the bacterial cytoskeleton and cell shape-determining proteins such as MreC, function in concert to orchestrate the localization of cell wall synthetic complexes resulting in spatially co-ordinated and efficient peptidoglycan synthetic activity.