首页 | 本学科首页   官方微博 | 高级检索  
     检索      


Tom22 is a multifunctional organizer of the mitochondrial preprotein translocase.
Authors:S van Wilpe  M T Ryan  K Hill  A C Maarse  C Meisinger  J Brix  P J Dekker  M Moczko  R Wagner  M Meijer  B Guiard  A H?nlinger  N Pfanner
Institution:Institute for Molecular Cell Biology, BioCentrum Amsterdam, The Netherlands.
Abstract:Mitochondrial preproteins are imported by a multisubunit translocase of the outer membrane (TOM), including receptor proteins and a general import pore. The central receptor Tom22 binds preproteins through both its cytosolic domain and its intermembrane space domain and is stably associated with the channel protein Tom40 (refs 11-13). Here we report the unexpected observation that a yeast strain can survive without Tom22, although it is strongly reduced in growth and the import of mitochondrial proteins. Tom22 is a multifunctional protein that is required for the higher-level organization of the TOM machinery. In the absence of Tom22, the translocase dissociates into core complexes, representing the basic import units, but lacks a tight control of channel gating. The single membrane anchor of Tom22 is required for a stable interaction between the core complexes, whereas its cytosolic domain serves as docking point for the peripheral receptors Tom20 and Tom70. Thus a preprotein translocase can combine receptor functions with distinct organizing roles in a multidomain protein.
Keywords:
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号