De Marchi Umberto, Sassi Nicola, Fioretti Bernard, Catacuzzeno Luigi, Cereghetti Grazia M, Szabò Ildikò, Zoratti Mario
Department of Biomedical Sciences, University of Padova, Padova, Italy.
Cell Calcium. 2009 May;45(5):509-16. doi: 10.1016/j.ceca.2009.03.014. Epub 2009 Apr 29.
Patch-clamping mitoplasts isolated from human colon carcinoma 116 cells has allowed the identification and characterization of the intermediate conductance Ca(2+)-activated K(+)-selective channel K(Ca)3.1, previously studied only in the plasma membrane of various cell types. Its identity has been established by its biophysical and pharmacological properties. Its localisation in the inner membrane of mitochondria is indicated by Western blots of subcellular fractions, by recording of its activity in mitochondria made fluorescent by a mitochondria-targeted fluorescent protein and by the co-presence of channels considered to be markers of the inner membrane. Moderate increases of mitochondrial matrix [Ca(2+)] will cause mtK(Ca)3.1 opening, thus linking inner membrane K(+) permeability and transmembrane potential to Ca(2+) signalling.
对从人结肠癌116细胞中分离出的线粒体进行膜片钳实验，使得中间电导钙激活钾选择性通道K（Ca）3.1得以鉴定和表征，该通道此前仅在各种细胞类型的质膜中进行过研究。其身份已通过其生物物理和药理学特性得以确定。通过亚细胞组分的蛋白质免疫印迹、在由线粒体靶向荧光蛋白标记为荧光的线粒体中记录其活性以及内膜标记通道的共同存在，表明其定位于线粒体内膜。线粒体基质中[Ca（2+）]的适度增加将导致mtK（Ca）3.1开放，从而将内膜K（+）通透性和跨膜电位与Ca（2+）信号传导联系起来。
