Plasma membrane voltage-dependent anion channel mediates antiestrogen-activated Maxi Cl- currents in C1300 neuroblastoma cells
Plasma membrane voltage-dependent anion channel mediates antiestrogen-activated Maxi Cl- currents in C1300 neuroblastoma cells
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DOI：
10.1074/jbc.m302814200
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发表时间：
2003-08-29
影响因子：
4.8
通讯作者：
Valverde, MA
中科院分区：
文献类型：
--
作者：
Bahamonde, MI;Fernández-Fernández, JM;Valverde, MA
在全细胞记录条件下，细胞膜大电导电压依赖性氯通道(Maxi Cl-通道)在不同类型的细胞中被记录到。然而，它的分子性质和与细胞生理学的相关性还有待阐明。其电生理特性类似于线粒体膜外膜的电压依赖性阴离子通道(VDAC)。这一观察结果导致了一种有争议的假设，即VDAC可能是质膜Maxi氯通道的分子相关者。我们研究了VDAC在C1300神经母细胞瘤细胞中的定位及其与抗雌激素激活的Maxi氯电流的关系。用抗VDAC的单抗对膜部分进行免疫印迹，并使用与编码其质膜分选所需的N末端前导肽的VDAC序列杂交的引物进行逆转录-聚合酶链式反应，证明了质膜VDAC的存在。此外，VDAC与质膜脂筏标记(霍乱毒素β亚基)共定位，但不与小窝蛋白-1共定位。将针对VDAC膜前导序列的反义寡核苷酸导入C1300细胞，可显著减少VDAC免疫染色和抗雌激素激活的Maxi氯电流，提示VDAC形成质膜Maxi氯通道或其一部分。
The cell membrane large conductance voltage-dependent chloride channel ( Maxi Cl- channel) has been recorded in different cell types following excision of membrane patches or stimulation by antiestrogens under whole-cell recording conditions. However, both its molecular nature and relevance to cell physiology await elucidation. Its electrophysiological properties resemble those of the voltage-dependent anion channel ( VDAC) of the outer mitochondrial membrane. This observation has led to the controversial hypothesis that VDAC could be the molecular correlate of the plasma membrane Maxi Cl- channel. We have investigated the cellular localization of VDAC and its relationship with the antiestrogen-activated Maxi Cl- current in C1300 neuroblastoma cells. The presence of a plasma membrane VDAC was demonstrated by immunoblotting of membrane fractions with monoclonal antibodies against the VDAC and by reverse transcription-PCR using primers that hybridize to a VDAC sequence coding for an N-terminal leader peptide required for its plasma membrane sorting. Besides, VDAC colocalized with markers of plasma membrane lipid rafts ( cholera toxin beta subunit) but not caveolin-1. Transfection of C1300 cells with an antisense oligonucleotide directed against the specific membrane leader sequence of VDAC markedly reduced both VDAC immunostaining and antiestrogen-activated Maxi Cl- currents, suggesting that VDAC forms the plasma membrane Maxi Cl- channel or a part thereof.