分子克隆和功能表达的心脏膜Na(+) -Ca2+交换器
D A Nicoll1, S Longoni, K D Philipson
1Department of Medicine, UCLA School of Medicine 90024-1760.
Science (New York, N.Y.)
|October 26, 1990
概括
研究人员确定了一种对心脏膜酸交换器 (NCX1) 的补充DNA (cDNA) 克隆. 这种克隆可以实现Na(+) -Ca2+交换器的功能表达,这对于心脏激发 - 收缩合至关重要.
科学领域:
- 心血管生理学心血管生理学
- 分子生物学分子生物学
- 生物化学 生物化学
背景情况:
- 心脏肉的Na(+) -Ca2+交换器对于在激发-收缩合过程中调节细胞内Ca2+至关重要.
- 了解这种载体的分子基础对于研究心脏功能至关重要.
研究的目的:
- 识别和描述编码心脏Na(+) -Ca2+交换机蛋白的互补DNA (cDNA).
- 为了使Na(+) -Ca2+载体的分子研究.
主要方法:
- 利用多克隆抗体选一个cDNA库.
- 进行北方斑分析以评估RNA杂交.
- 进行了水变性分析和序列相似性比较.
- 为抗体生产和免疫阻塞生成的合成.
- 在Xenopus卵细胞中注射合成RNA用于功能表达研究.
主要成果:
- 确定了一个编码Na(+) -Ca2+交换机蛋白的cDNA克隆.
- 该cDNA混合为7-基基RNA,并包含一个970-氨基酸开放的读取框架.
- 水合性分析表明多个跨膜螺旋环,其序列与Na(+) -和K(+) -依赖的ATPase相似.
- 抗体与70,120和160kDa的 sarcolemmal 蛋白质发生反应.
- 从cDNA合成的RNA诱导了Xenopus卵细胞中的Na(+) -Ca2+交换活动.
结论:
- 已识别的cDNA克隆代表了心脏Na(+) -Ca2+交换器.
- 这种分子工具允许功能表达,并进一步研究传送器在心脏生理学中的作用.
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