Glutamate-induced assembly of bacterial cell division protein FtsZ
Glutamate-induced assembly of bacterial cell division protein FtsZ
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DOI：
10.1074/jbc.m205760200
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发表时间：
2003-02-07
影响因子：
4.8
通讯作者：
Panda, D
中科院分区：
文献类型：
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作者：
Beuria, TK;Krishnakumar, SS;Panda, D
FtsZ的聚合是一个精细调控的过程，在细菌细胞分裂过程中起着重要作用。然而，目前已知的FtsZ聚合调节剂很少。我们发现谷氨酸钠是FtsZ聚合的有效诱导剂。在GTP存在的情况下，谷氨酸增加了FtsZ的聚合速率和程度，并呈浓度依赖性；约90%的蛋白质在1 m谷氨酸存在下以聚合物形式沉积。谷氨酸诱导聚合物的电子显微照片显示出大的丝状结构和广泛的束结。此外，谷氨酸对聚合物具有较强的稳定作用，防止稀释引起的分解，并降低了FtsZ的GTPase活性。钙诱导的FtsZ聚合及FtsZ聚合物的成束有趣的是，虽然1 m谷氨酸产生的光散射信号比10 mm钙产生的光散射信号大，但在1 m谷氨酸和10 mm钙存在下的聚合物沉积量相似。因此，谷氨酸存在时增加的光散射一定是由于它比钙能诱导更广泛的FtsZ聚合物捆绑。提示钙和谷氨酸可能通过不同的机制诱导FtsZ聚合。
The polymerization of FtsZ is a finely regulated process that plays an essential role in the bacterial cell division process. However, only a few modulators of FtsZ polymerization are known. We identified monosodium glutamate as a potent inducer of FtsZ polymerization. In the presence of GTP, glutamate enhanced the rate and extent of polymerization of FtsZ in a concentration-dependent manner; similar to90% of the protein was sedimented as polymer in the presence of 1 m glutamate. Electron micrographs of glutamate-induced polymers showed large filamentous structures with extensive bundling. Furthermore, glutamate strongly stabilized the polymers against dilution-induced disassembly, and it decreased the GTPase activity of FtsZ. Calcium induced FtsZ polymerization and bundling of FtsZ polymers; interestingly, although 1 m glutamate produced a larger light-scattering signal than produced by 10 mm calcium, the amount of polymer sedimented in the presence of 1 m glutamate and 10 mm calcium was similar. Thus, the increased light scattering in the presence of glutamate must be due to its ability to induce more extensive bundling of FtsZ polymers than calcium. The data suggest that calcium and glutamate might induce FtsZ polymerization by different mechanisms.