Role of membrane potential and calcium in chemotactic sensing by bacteria.
Role of membrane potential and calcium in chemotactic sensing by bacteria.
复制标题
膜电位和钙在细菌趋化传感中的作用。
DOI：
10.1016/0022-2836(81)90300-4
复制
发表时间：
1981
影响因子：
5.6
通讯作者：
KoshlandJr,DE
中科院分区：
文献类型：
--
作者：
Snyder,MA;Stock,JB;KoshlandJr,DE
使用渗透性亲脂性阳离子（氯化四苯基鏻）和荧光染料（3-丙基-2-(5-(3-丙基-2(3H)-苯并噻唑亚基)-1,3-戊二烯基)碘化物）测量埃希氏菌膜电位响应各种趋化刺激的变化。一些引诱剂和排斥剂引起永久性、单调的去极化或超极化。然而，并非所有化学效应器都会产生潜在的变化，并且变化的方向与对这些化合物的生理反应并不相关。此外，在许多趋化突变体中观察到变化。从这些结果中，我们得出结论，化学刺激影响的膜电位扰动与趋化传感无关。这些发现以及细胞质离子条件和膜电位之间的密切相关性使我们研究了钙在趋化性中的作用。通过在钙螯合剂存在下培养细胞，我们能够将细胞钙水平降低十倍以上，而行为没有改变。这些结果表明这些细胞中的感觉转导不是由该阳离子介导的。
Changes inEscherichia colimembrane potential in response to a wide variety of chemotactic stimuli were measured using a permeant, lipophilic cation (tetraphenylphosphonium chloride) and a fluorescent dye (3-propyl-2-(5-(3-propyl-2(3H)-benzothiazolylidene)-1,3-pentadienyl)iodide). Some attractants and repellants caused permanent, monotonic depolarizations or hyperpolarizations. Not all chemoeffectors, however, produced potential changes, and the direction of change did not correlate with physiological responses to these compounds. Moreover, changes were observed in a number of chemotactic mutants. From these results, we conclude that perturbations in membrane potential effected by chemical stimuli are not related to chemotactic sensing. These findings, and the close correlation between cytoplasmic ionic conditions and membrane potential, led us to examine the role of calcium in chemotaxis. By growing cells in the presence of a calcium chelator, we were able to lower cellular calcium levels over tenfold, with no change in behavior. These results indicate that sensory transduction in these cells is not mediated by this cation.