Carballido-López Rut, Formstone Alex, Li Ying, Ehrlich S Dusko, Noirot Philippe, Errington Jeff
Génétique Microbienne, Institut National de la Recherche Agronomique, 78352 Jouy-en-Josas Cedex, France.
Dev Cell. 2006 Sep;11(3):399-409. doi: 10.1016/j.devcel.2006.07.017.
MreB proteins are bacterial actin homologs involved in cell morphogenesis and various other cellular processes. However, the effector proteins used by MreBs remain largely unknown. Bacillus subtilis has three MreB isoforms. Mbl and possibly MreB have previously been shown to be implicated in cell wall synthesis. We have now found that the third isoform, MreBH, colocalizes with the two other MreB isoforms in B. subtilis and also has an important role in cell morphogenesis. MreBH can physically interact with a cell wall hydrolase, LytE, and is required for its helical pattern of extracellular localization. Moreover, lytE and mreBH mutants exhibit similar cell-wall-related defects. We propose that controlled elongation of rod-shaped B. subtilis depends on the coordination of cell wall synthesis and hydrolysis in helical tracts defined by MreB proteins. Our data also suggest that physical interactions with intracellular actin bundles can influence the later localization pattern of extracellular effectors.
MreB蛋白是细菌肌动蛋白的同源物，参与细胞形态发生和各种其他细胞过程。然而，MreB所使用的效应蛋白在很大程度上仍不为人知。枯草芽孢杆菌有三种MreB异构体。先前已证明Mbl以及可能还有MreB与细胞壁合成有关。我们现在发现，第三种异构体MreBH与枯草芽孢杆菌中的其他两种MreB异构体共定位，并且在细胞形态发生中也具有重要作用。MreBH可以与细胞壁水解酶LytE发生物理相互作用，并且是其细胞外定位螺旋模式所必需的。此外，lytE和mreBH突变体表现出类似的细胞壁相关缺陷。我们提出，杆状枯草芽孢杆菌的受控伸长取决于由MreB蛋白定义的螺旋区域中细胞壁合成与水解的协调。我们的数据还表明，与细胞内肌动蛋白束的物理相互作用可以影响细胞外效应器的后期定位模式。
