Intracellular free calcium responses during chemotaxis of Dictyostelium cells.
Intracellular free calcium responses during chemotaxis of Dictyostelium cells.
复制标题
盘基网柄菌细胞趋化过程中的细胞内游离钙反应。
作者：
S. Yumura;K. Furuya;I. Takeuchi
通过电穿孔将钙离子指示剂 fura-2 牛血清白蛋白引入盘基网柄菌细胞中。在用亚微摩尔浓度的叶酸刺激后，营养细胞中细胞内钙离子 ([Ca2+]i) 的浓度短暂增加，叶酸是该生物体在营养阶段的化学引诱剂。在用亚纳摩尔浓度的 cAMP（聚集阶段的化学引诱剂）刺激后，在聚集活性细胞中也观察到类似的 [Ca2+]i 反应。 cAMP引起的[Ca2+]i反应比叶酸引起的高2.1倍。这些反应的强度取决于外部缓冲液中 Ca2+ 的浓度。镁离子的存在以剂量依赖性方式抑制[Ca2+]i 反应。在表面自由迁移的细胞中，后部区域的[Ca2+]i 高于前部区域，尽管这种梯度并不总是维持。当使用含有cAMP的微毛细管局部刺激聚集感受态细胞时，细胞将伪足向微毛细管延伸。在这些情况下，在与毛细管尖端相对的区域中短暂地观察到[Ca2+]i 的增加。在蛞蝓阶段，蛞蝓前柄细胞中的[Ca2+]i含量高于前孢子细胞。讨论了 [Ca2+]i 在细胞内受到空间调节的可能性。
A calcium ion indicator, fura-2 bovine serum albumin, was introduced into Dictyostelium discoideum cells by electroporation. The concentration of intracellular calcium ions ([Ca2+]i) increased transiently in vegetative cells upon stimulation with submicromolar concentrations of folic acid, a chemoattractant for this organism at the vegetative stage. Similar [Ca2+]i responses were also observed in aggregation-competent cells upon stimulation with subnanomolar concentrations of cAMP, a chemoattractant at the aggregation stage. The [Ca2+]i response caused by cAMP was 2.1 times higher than that caused by folic acid. The magnitude of these responses depended on the concentration of Ca2+ in the external buffer. The presence of magnesium ions inhibited the [Ca2+]i responses in a dose-dependent manner. [Ca2+]i was higher in the rear region than in the anterior region of cells freely migrating on the surface, although such a gradient was not always maintained. When aggregation competent cells were locally stimulated by the application of a microcapillary containing cAMP, the cells extended pseudopods toward the microcapillary. In these cases, an increase in [Ca2+]i was transiently observed in the region opposite to the tip of the capillary. At the slug stage, [Ca2+]i was higher in prestalk cells than in prespore cells of slugs. The possibility that the [Ca2+]i is spatially regulated within a cell was discussed.
表达水母脱辅基水母发光蛋白的盘基网柄菌多细胞阶段的游离钙模式。
DOI：
10.1242/dev.121.8.2291
发表时间：
1995
期刊：
Development (Cambridge, England)
影响因子：
--
作者：
Cubitt,AB;Firtel,RA;Fischer,G;Jaffe,LF;Miller,AL
通讯作者：
Miller,AL
影响因子：
56.9
作者：
BRUNDAGE, RA;FOGARTY, KE;FAY, FS
通讯作者：
FAY, FS