Expression of an omega-conotoxin-sensitive calcium channel in Xenopus oocytes injected with mRNA from Torpedo electric lobe.
Expression of an omega-conotoxin-sensitive calcium channel in Xenopus oocytes injected with mRNA from Torpedo electric lobe.
复制标题
注射鱼雷电叶 mRNA 的非洲爪蟾卵母细胞中 omega-芋螺毒素敏感钙通道的表达。
DOI：
10.1073/pnas.84.15.5464
复制
发表时间：
1987
影响因子：
11.1
通讯作者：
Gundersen,CB
中科院分区：
文献类型：
--
作者：
Umbach,JA;Gundersen,CB
用加利福尼亚鱼雷电叶分离的poly(A)+ RNA注射非洲爪蟾卵母细胞。卵母细胞注射mRNA后6 ~ 9天，在含40 mM钡的无钙和氯化物溶液中，卵母细胞可以检测到镉敏感的内向电流。这种向内电流与对照卵母细胞的天然钡电流不同，其对镉离子的阻断具有较高的敏感性，并能被欧米伽-conotoxin（一种来自Conus geographicus的多肽神经毒素）抑制。尼索地平（1 μ m）和尼群地平（1 μ m）对对照细胞和注射细胞的电流均无明显影响。然而，对照卵母细胞的钡电流（在用于记录的钡溶液中）比注射mrna的卵母细胞中出现的ω -conotoxin敏感电流明显更多地失活。在含有放线菌素D的培养基中培养注射了mrna的卵母细胞不能阻止ω -conotoxin敏感电流的出现。这些结果支持了来自鱼雷电瓣的mRNA在爪蟾卵母细胞中被翻译以产生额外的钙通道的结论。该通道的特征表明，它可能是同一类型的钙通道，控制神经末梢的递质释放在鱼雷电火花。
Xenopus laevis oocytes were injected with poly(A)+ RNA isolated from the electric lobe of Torpedo californica. Six to nine days after mRNA injection of the oocytes a cadmium-sensitive inward current could be detected in oocytes bathed in a calcium- and chloride-free solution containing 40 mM barium. This inward current could be distinguished from the native barium current of control oocytes by its high sensitivity to blockade by cadmium ions and its inhibition by omega-conotoxin, a peptide neurotoxin from Conus geographicus. Neither the current of control cells nor that of injected cells was detectably affected by nisoldipine (1 microM) or nitrendipine (1 microM). However, the barium current of control oocytes showed appreciably more inactivation (in the barium solution used for recording) than the omega-conotoxin-sensitive current that develops in mRNA-injected oocytes. Culturing of mRNA-injected oocytes in medium containing actinomycin D failed to prevent the appearance of the omega-conotoxin-sensitive current. These results support the conclusion that mRNA from Torpedo electric lobe is translated to produce an additional calcium channel in Xenopus oocytes. The features of this channel suggest that it may be the same type of calcium channel that controls transmitter release at nerve endings in Torpedo electroplax.