PDF(Pubmed)
Abstract：
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.
摘要：
细胞运动性普遍依赖于将基质连接到细胞马达的粘着斑复合物（FA）的空间调节。在细菌FAs中,冒险的滑行运动机制（Agl-Glt）沿着细胞轴沿着相互的滑行运动蛋白（MglA）-鸟苷5'-三磷酸（GTP）梯度在前导细胞极处组装。这里,我们展示了GltJ,一种机械膜蛋白，包含结合MglA-GTP和AglZ的胞质基序，并募集MreB细胞骨架以启动向滞后细胞极的运动。此外,MglA-GTP结合触发了相邻的GltJ锌指结构域的构象转变，促进在落后极点附近的MglB招募。这促使MglA水解GTP，导致复杂的拆卸。因此，GltJ开关用作MglA-GTP梯度的传感器，在空间上控制FA活性。
