Molecular analysis and sensitivity to arachidonic acid of voltage-dependent KィイD1+ィエD1 channel, Kv4.3

原位杂交和RT-PCR分析表明，在三个Kv4.3剪接变体（a，B，和c）与不同的C-末端胞质结构域，Kv4.3 a的mRNA是丰富的大脑皮层，小脑，嗅球，延髓，而Kv4.3 c的mRNA主要定位于海马。通过RT-PCR从大鼠脑中分离出三种新的Kv4.3剪接变异体（Kv4.3d、e和f），它们分别由601、635和628个氨基酸组成，并且具有不同的C-末端胞质结构域。Kv4.3b、d、e和f在脑中以低得多的水平表达。在HEK 293细胞中的异源表达中测量，去除Kv4.3a的C-末端结构域中的149个氨基酸的诱变显著减慢了其从失活的恢复速率。然而，令人惊讶的是，无论是失活的速率，也没有激活和失活的电压依赖性改变。

In situ hybridization and RT-PCR analyses has revealed that, among three Kv4.3 splice variants (a, b, and c) with distinct C-terminal cytoplasmic domains, the mRNA for Kv4.3a is abundant in cerebral cortex, cerebellum, olfactory bulb, and medulla oblongata, whereas the mRNA of Kv4.3c is localized mainly to hippocampus. Three new distinct splice variants of Kv4.3 (Kv4.3d, e and f), which consist of 601, 635, and 628 amino acids, respectively, and have divergent C-terminal cytoplasmic domains, were isolated from rat brain by RT-PCR. Kv4.3b, d, e and f are expressed at much lower levels in brain. Mutagenesis which removed 149 amino acids in C-terminal domain of Kv4.3a significantly slowed its rate of recovery from inactivation as measured in heterologous expression in HEK293 cells. Surprisingly, however, neither the rate of inactivation nor voltage dependence of the activation and inactivation were changed.