The pro-apoptotic BH3-only protein Bim interacts with components of the translocase of the outer mitochondrial membrane (TOM).
The pro-apoptotic BH3-only protein Bim interacts with components of the translocase of the outer mitochondrial membrane (TOM).
复制标题
DOI：
10.1371/journal.pone.0123341
复制
发表时间：
2015
期刊：
影响因子：
3.7
通讯作者：
Weber A
中科院分区：
文献类型：
--
作者：
Frank DO;Dengjel J;Wilfling F;Kozjak-Pavlovic V;Häcker G;Weber A
促细胞凋亡Bcl-2家族蛋白Bim属于已知为细胞凋亡启动子的仅BH 3蛋白。最近的数据显示Bim通过C-末端跨膜锚组成性地插入线粒体外膜，从那里它可以激活细胞色素c释放的效应子Bax。为了鉴定Bim活性的调节剂，我们进行了在线粒体中与Bim相互作用的蛋白质的搜索。我们发现Bim与Tom 70，Tom 20和更弱的Tom 40，外膜转位酶（TOM）的所有组件的相互作用。在胰蛋白酶消化的酵母线粒体上进行的体外进口测定显示减少的Bim插入到线粒体外膜（OMM）中，表明蛋白质受体可能参与进口过程。然而，通过siRNA针对TOM组分（Tom 40、Tom 70、Tom 22或Tom 20）的RNAi，单独或组合，在稳定状态下或在从头诱导后，并不一致地改变HeLa线粒体上Bim的量。支持这一点，单独或联合敲除TOM受体也未能改变HeLa细胞对Bim诱导的细胞凋亡的易感性。在分离的酵母线粒体中，缺乏Tom 70或单独的TOM组分Tom 20或Tom 22并不影响Bim输入到线粒体外膜中。在酵母中，Bim的表达可以使细胞对α-依赖性杀伤敏感。这种致敏作用不受Tom 70缺失或Tom 40实验性减少的影响。因此，虽然Bim-TOM相互作用的生理作用仍然不清楚，TOM复合物的成分似乎并不是必不可少的Bim插入到OMM。然而，这种关联应注意到，并考虑在其他细胞和情况下的Bim的调节进行调查时。
The pro-apoptotic Bcl-2-family protein Bim belongs to the BH3-only proteins known as initiators of apoptosis. Recent data show that Bim is constitutively inserted in the outer mitochondrial membrane via a C-terminal transmembrane anchor from where it can activate the effector of cytochrome c-release, Bax. To identify regulators of Bim-activity, we conducted a search for proteins interacting with Bim at mitochondria. We found an interaction of Bim with Tom70, Tom20 and more weakly with Tom40, all components of the Translocase of the Outer Membrane (TOM). In vitro import assays performed on tryptically digested yeast mitochondria showed reduced Bim insertion into the outer mitochondrial membrane (OMM) indicating that protein receptors may be involved in the import process. However, RNAi against components of TOM (Tom40, Tom70, Tom22 or Tom20) by siRNA, individually or in combination, did not consistently change the amount of Bim on HeLa mitochondria, either at steady state or upon de novo-induction. In support of this, the individual or combined knock-downs of TOM receptors also failed to alter the susceptibility of HeLa cells to Bim-induced apoptosis. In isolated yeast mitochondria, lack of Tom70 or the TOM-components Tom20 or Tom22 alone did not affect the import of Bim into the outer mitochondrial membrane. In yeast, expression of Bim can sensitize the cells to Bax-dependent killing. This sensitization was unaffected by the absence of Tom70 or by an experimental reduction in Tom40. Although thus the physiological role of the Bim-TOM-interaction remains unclear, TOM complex components do not seem to be essential for Bim insertion into the OMM. Nevertheless, this association should be noted and considered when the regulation of Bim in other cells and situations is investigated.
登录
查看更多内容
影响因子：
16
作者：
Dehan, Elinor;Bassermann, Florian;Guardavaccaro, Daniele;Vasiliver-Shamis, Gaia;Cohen, Michael;Lowes, Kym N.;Dustin, Michael;Huang, David C. S.;Taunton, Jack;Pagano, Michele
通讯作者：
Pagano, Michele
影响因子：
14.8
作者：
Rappsilber, Juri;Mann, Matthias;Ishihama, Yasushi
通讯作者：
Ishihama, Yasushi
影响因子：
4
作者：
Kemper, Christian;Habib, Shukry J.;Rapaport, Doron
通讯作者：
Rapaport, Doron
DOI：
10.1073/pnas.91.20.9238
发表时间：
1994-09-27
影响因子：
11.1
作者：
SATO, T;HANADA, M;REED, JC
通讯作者：
REED, JC
影响因子：
64.8
作者：
van Wilpe, S;Ryan, MT;Pfanner, N
通讯作者：
Pfanner, N