Tim23 - Tim50 pair coordinates functions of translocators and motor proteins in mitochondrial protein import

Yasushi Tamura, Yoshihiro Harada, Takuya Shiota, Koji Yamano, Kazuaki Watanabe, Mihoko Yokota, Hayashi Yamamoto, Hiromi Sesaki, Toshiya Endo

Research output: Contribution to journalArticleResearchpeer-review

99 Citations (Scopus)


Mitochondrial protein traffi c requires coordinated operation of protein translocator complexes in the mitochondrial membrane. The TIM23 complex translocates and inserts proteins into the mitochondrial inner membrane. Here we analyze the intermembrane space (IMS) domains of Tim23 and Tim50, which are essential subunits of the TIM23 complex, in these functions. We fi nd that interactions of Tim23 and Tim50 in the IMS facilitate transfer of precursor proteins from the TOM40 complex, a general protein translocator in the outer membrane, to the TIM23 complex. Tim23 - Tim50 interactions also facilitate a late step of protein translocation across the inner membrane by promoting motor functions of mitochondrial Hsp70 in the matrix. Therefore, the Tim23- Tim50 pair coordinates the actions of the TOM40 and TIM23 complexes together with motor proteins for mitochondrial protein import.

Original languageEnglish
Pages (from-to)129-141
Number of pages13
JournalJournal of Cell Biology
Issue number1
Publication statusPublished - 12 Jan 2009
Externally publishedYes

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