Laboratoire d'Ingénierie des Systèmes Macromoléculaires (LISM), Institut de Microbiologie de la Méditerranée (IMM), CNRS - Aix-Marseille Université UMR7255, 31 Chemin Joseph Aiguier CS70071, 13402 Marseille Cedex 20, France.
Laboratoire de Chimie Bactérienne (LCB), Institut de Microbiologie de la Méditerranée (IMM), Turing Center for Living Systems, CNRS - Aix-Marseille Université UMR7283, 31 Chemin Joseph Aiguier CS70071, 13402 Marseille Cedex 20, France.
Sci Adv. 2024 May 31;10(22):eadn2789. doi: 10.1126/sciadv.adn2789. Epub 2024 May 29.
Cell motility universally relies on spatial regulation of focal adhesion complexes (FAs) connecting the substrate to cellular motors. In bacterial FAs, the Adventurous gliding motility machinery (Agl-Glt) assembles at the leading cell pole following a Mutual gliding-motility protein (MglA)-guanosine 5'-triphosphate (GTP) gradient along the cell axis. Here, we show that GltJ, a machinery membrane protein, contains cytosolic motifs binding MglA-GTP and AglZ and recruiting the MreB cytoskeleton to initiate movement toward the lagging cell pole. In addition, MglA-GTP binding triggers a conformational shift in an adjacent GltJ zinc-finger domain, facilitating MglB recruitment near the lagging pole. This prompts GTP hydrolysis by MglA, leading to complex disassembly. The GltJ switch thus serves as a sensor for the MglA-GTP gradient, controlling FA activity spatially.
细胞运动普遍依赖于细胞骨架与基质相连的粘着斑复合物(FA)的空间调节。在细菌 FA 中,冒险滑行运动机制(Agl-Glt)沿着细胞轴在细胞前极根据相互滑行运动蛋白(MglA)-鸟苷 5'-三磷酸(GTP)梯度组装。在这里,我们表明,机器膜蛋白 GltJ 包含细胞质基序,可结合 MglA-GTP 和 AglZ,并招募 MreB 细胞骨架以向滞后细胞极移动。此外,MglA-GTP 结合触发相邻 GltJ 锌指结构域的构象变化,促进 MglB 在滞后极附近的募集。这促使 MglA 水解 GTP,导致复合物解体。因此,GltJ 开关充当 MglA-GTP 梯度的传感器,空间控制 FA 活性。