Kim I, Koh G Y, Lee C O
Department of Life Science, Pohang University of Science and Technology, Korea.
Comp Biochem Physiol B Biochem Mol Biol. 1998 Jan;119(1):157-61. doi: 10.1016/s0305-0491(97)00299-x.
Alternatively spliced isoforms of Na(+)-Ca2+ exchanger were found from various tissues and species. RT-PCR amplification was performed on the basis of our cloned mouse cardiac Na(+)-Ca2+ exchanger and four alternatively spliced isoforms of Na(+)-Ca2+ exchanger were identified. Three (NCX1.3, NCX1.4, and NCX1.12) of them were first identified in the heart, and one isoform (NCX1.12) was a novel spliced variant. These four spliced variants were present in the embryonic and adult atria and ventricles. Different cell types of the heart expressed different spliced isoforms of Na(+)-Ca2+ exchanger. Southern blot analysis indicated that the Na(+)-Ca2+ exchanger gene existed as a single copy in the mouse genome. Thus, the Na(+)-Ca2+ exchanger isoforms expressed in mouse heart are consistent with being produced by alternative splicing and they may have different functions in various cell types in the mouse heart.
在多种组织和物种中发现了钠钙交换体的可变剪接异构体。基于我们克隆的小鼠心脏钠钙交换体进行了逆转录聚合酶链反应（RT-PCR）扩增，并鉴定出四种钠钙交换体的可变剪接异构体。其中三种（NCX1.3、NCX1.4和NCX1.12）首次在心脏中被鉴定出来，一种异构体（NCX1.12）是一种新的剪接变体。这四种剪接变体存在于胚胎和成年期的心房和心室中。心脏的不同细胞类型表达不同的钠钙交换体剪接异构体。Southern印迹分析表明，钠钙交换体基因在小鼠基因组中以单拷贝形式存在。因此，在小鼠心脏中表达的钠钙交换体异构体与通过可变剪接产生的情况一致，并且它们可能在小鼠心脏的各种细胞类型中具有不同的功能。
