Tubulin is an inherent component of mitochondrial membranes that interacts with the voltage-dependent anion channel
Tubulin is an inherent component of mitochondrial membranes that interacts with the voltage-dependent anion channel
复制标题
DOI：
10.1074/jbc.m203834200
复制
发表时间：
2002-09-13
影响因子：
4.8
通讯作者：
Braguer, D
中科院分区：
文献类型：
--
作者：
Carré, M;André, N;Braguer, D
我们以前曾报道，抗微管蛋白剂诱导细胞色素c从分离的线粒体释放。在这项研究中，我们发现微管蛋白存在于从不同的人类癌细胞系和非癌细胞系分离的线粒体中。检查聚合的微管和胞质蛋白的不存在，以确保该微管蛋白是线粒体的固有组分。此外，盐洗涤不从线粒体释放微管蛋白。通过电子显微镜，我们发现微管蛋白定位于线粒体膜。与细胞微管蛋白相比，线粒体微管蛋白富含乙酰化和酪氨酸化的α-微管蛋白，也富含III类β-微管蛋白同种型，但含有非常少的IV类β-微管蛋白同种型。线粒体微管蛋白可能以α/β二聚体组织，占总细胞微管蛋白的2.2 +/-0.5%。最后，我们通过免疫沉淀实验表明，线粒体微管蛋白与渗透性转换孔的主要成分-电压依赖性阴离子通道特异性相关。因此，微管蛋白是线粒体膜的固有成分，它可以通过与通透性转换孔的相互作用在细胞凋亡中发挥作用。
We have previously reported that anti-tubulin agents induce the release of cytochrome c from isolated mitochondria. In this study, we show that tubulin is present in mitochondria isolated from different human cancerous and non-cancerous cell lines. The absence of polymerized microtubules and cytosolic proteins was checked to ensure that this tubulin is an inherent component of the mitochondria. In addition, a salt wash did not release the tubulin from the mitochondria. By using electron microscopy, we then showed that tubulin is localized in the mitochondrial membranes. As compared with cellular tubulin, mitochondrial tubulin is enriched in acetylated and tyrosinated alpha-tubulin and is also enriched in the class III beta-tubulin isotype but contains very little of the class IV beta-tubulin isotype. The mitochondrial tubulin is likely to be organized in alpha/beta dimers and represents 2.2 +/- 0.5% of total cellular tubulin. Lastly, we showed by immunoprecipitation experiments that the mitochondrial tubulin is specifically associated with the voltage-dependent anion channel, the main component of the permeability transition pore. Thus, tubulin is an inherent component of mitochondrial membranes, and it could play a role in apoptosis via interaction with the permeability transition pore.