Porin Associates with Tom22 to Regulate the Mitochondrial Protein Gate Assembly
Porin Associates with Tom22 to Regulate the Mitochondrial Protein Gate Assembly
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DOI：
10.1016/j.molcel.2019.01.003
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发表时间：
2019-03-07
期刊：
影响因子：
16
通讯作者：
Endo, Toshiya
中科院分区：
文献类型：
--
作者：
Sakaue, Haruka;Shiota, Takuya;Endo, Toshiya
线粒体几乎所有的驻留蛋白都是从细胞质中输入的，而TOM复合体则是它们的入口。TOM复合体经历了三通道网关的多数种群(“Trimer”)和缺乏Tom22且只有两个Tom40通道的少数种群(“dimer”)之间的动态转换。在这里，我们发现Porin Por1起到了结合新进口Tom22的水槽的作用。这种Por1结合从而调节Tom22整合到TOM复合体中，保证了功能性三聚体TOM复合体的形成。从三聚体TOM复合体中分离出来的Tom22的Por1隔离也增强了二聚体TOM复合体，这有利于TIM40/MIA依赖的蛋白质进入线粒体。此外，PON1似乎通过陪伴单体Tom22促进功能性三聚体TOM复合体的细胞周期依赖性变异，而单体Tom22是由磷酸化的Tom6的细胞周期控制的变异引起的。
Mitochondria import nearly all of their resident proteins from the cytosol, and the TOM complex functions as their entry gate. The TOM complex undergoes a dynamic conversion between the majority population of a three-channel gateway ("trimer'') and the minor population that lacks Tom22 and has only two Tom40 channels ("dimer''). Here, we found that the porin Por1 acts as a sink to bind newly imported Tom22. This Por1 association thereby modulates Tom22 integration into the TOM complex, guaranteeing formation of the functional trimeric TOM complex. Por1 sequestration of Tom22 dissociated from the trimeric TOM complex also enhances the dimeric TOM complex, which is preferable for the import of TIM40/MIA-dependent proteins into mitochondria. Furthermore, Por1 appears to contribute to cell-cycle-dependent variation of the functional trimeric TOM complex by chaperoning monomeric Tom22, which arises from the cell-cycle-controlled variation of phosphorylated Tom6.