EXPRESSION OF AN OUTWARD-RECTIFYING POTASSIUM CHANNEL FROM MAIZE MESSENGER-RNA AND COMPLEMENTARY RNA IN XENOPUS OOCYTES
EXPRESSION OF AN OUTWARD-RECTIFYING POTASSIUM CHANNEL FROM MAIZE MESSENGER-RNA AND COMPLEMENTARY RNA IN XENOPUS OOCYTES
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DOI：
10.1105/tpc.4.8.961
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发表时间：
1992-08-01
期刊：
影响因子：
11.6
通讯作者：
SCHROEDER, JI
中科院分区：
文献类型：
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作者：
CAO, YW;ANDEROVA, M;SCHROEDER, JI
将从不同植物（玉米、黄瓜和南瓜）中分离出的 Poly(A)+ mRNA 注射到非洲爪蟾卵母细胞中，会出现电压和时间依赖性、钾选择性的外向电流，该电流类似于许多高等植物细胞中记录的外向整流钾电流。人们发现玉米芽中编码这种活性的 mRNA 特别丰富。在载体 lambda-ZAPII 中构建玉米芽 mRNA 的 cDNA 文库，并用于合成与 cDNA 互补的 RNA (cRNA)。注射 cRNA 产生外向整流钾电流，其特性与注射 Poly(A)+ mRNA 获得的电流相似。这些结果表明，高等植物 mRNA 可以正确翻译成在非洲爪蟾卵母细胞质膜中产生电压调节钾通道的产物。因此，非洲爪蟾卵母细胞可作为异源表达系统用于植物离子通道基因的功能鉴定和分离以及植物离子通道结构与功能关系的研究。
Injection of Xenopus oocytes with poly(A)+ mRNA isolated from different plants (maize, cucumber, and squash) results in the appearance of a voltage- and time-dependent, potassium-selective, outward current that is similar to the outward-rectifying potassium current recorded in many higher plant cells. Maize shoots were found to be especially enriched in mRNA encoding such activity. A cDNA library of maize shoot mRNA was constructed in the vector lambda-ZAPII and was used to synthesize RNA complementary to the cDNA (cRNA). Injection of the cRNA gave rise to an outward-rectifying potassium current with properties similar to the currents obtained by poly(A)+ mRNA injection. These results demonstrate that higher plant mRNA can be properly translated into a product that produces a voltage-regulated potassium channel in the plasma membrane of Xenopus oocytes. Thus, Xenopus oocytes can be used as a heterologous expression system for the functional identification and isolation of plant ion channel genes as well as for the study of structure-function relationship of plant ion channels.