Channel induction by palytoxin in yeast cells expressing Na+,K+‐ATPase or its chimera with sarco/endoplasmic reticulum Ca2+‐ATPase-猫眼课题宝

表达 Na+,K+-ATP 酶或其与肌浆/内质网 Ca2+-ATP 酶的嵌合体的酵母细胞中海藻毒素的通道诱导

DOI：

10.1016/s0014-5793(03)00418-6

发表时间：

2003

期刊：

FEBS Letters

影响因子：

3.5

通讯作者：

中科院分区：

生物学3区

文献类型：

作者：

Katsuaki Ito;I. Toyoda;M. Higashiyama;D. Uemura;Masa H. Sato;S. Yoshimura;T. Ishii;K. Takeyasu

海葵毒素（Palytoxin，PTX）通过与Na ~+，K ~+-ATP酶相互作用诱导阳离子通道。目前还不清楚这种作用与酶催化活性的关系。我们研究了PTX的作用是否依赖于Na+，K+-ATP酶特异性的催化结构域。将野生型Na+，K+-ATP酶α亚基（NNN）或其嵌合体（NCN）与β亚基共表达于酿酒酵母（Saccharomycescerevisiae）中。PTX（0.1-100 nM）在NNN-或NCN-转染细胞中增加K+流出的程度相似，但在非转染细胞中则不然。当哇巴因抗性NNN和NCN表达时，PTX也增加K+流出。哇巴因在NNN或NCN细胞中抑制PTX的作用，但在哇巴因抗性细胞中不抑制。这些数据表明，PTX的通道形成作用不依赖于催化结构域物种。

Palytoxin (PTX) induces a cation channel through interaction with Na+,K+-ATPase. It is unclear how this action relates to the enzyme catalytic activity. We examined whether the action of PTX depends on the catalytic domain specific for Na+,K+-ATPase. Wild-type Na+,K+-ATPase α-subunit (NNN) or its chimera (NCN), in which the catalytic domain was replaced with that of sarcoplasmic/endoplasmic reticulum Ca2+-ATPase, was co-expressed with β-subunit in the yeast Saccharomyces cerevisiae. PTX (0.1–100 nM) increased K+efflux in NNN- or NCN-transfected cells to a similar degree but not in non-transfected cells. When ouabain-resistant NNN and NCN were expressed, PTX also increased K+efflux. Ouabain inhibited the effect of PTX in NNN or NCN cells but not in ouabain-resistant cells. These data suggest that the channel-forming action of PTX does not depend on the catalytic domain species.

The amino-terminal 200 amino acids of the plasma membrane Na+,K+-ATPase alpha subunit confer ouabain sensitivity on the sarcoplasmic reticulum Ca(2+)-ATPase.