Deletion of Mgr2p affects the gating behavior of the TIM23 complex

Oygul Mirzalieva, Shinhye Jeon, Kevin Damri, Ruth Hartke, Layla Drwesh, Keren Demishtein-Zohary, Abdussalam Azem, Cory D. Dunn, Pablo M. Peixoto*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

3 Scopus citations


The TIM23 complex is a hub for translocation of preproteins into or across the mitochondrial inner membrane. This dual sorting mechanism is currently being investigated, and in yeast appears to be regulated by a recently discovered subunit, the Mgr2 protein. Deletion of Mgr2p has been found to delay protein translocation into the matrix and accumulation in the inner membrane. This result and other findings suggested that Mgr2p controls the lateral release of inner membrane proteins harboring a stop-transfer signal that follows an N-terminal amino acid signal. However, the mechanism of lateral release is unknown. Here, we used patch clamp electrophysiology to investigate the role of Mgr2p on the channel activity of TIM23. Deletion of Mgr2p decreased normal channel frequency and increased occurrence of a residual TIM23 activity. The residual channel lacked gating transitions but remained sensitive to synthetic import signal peptides. Similarly, a G145L mutation in Tim23p displaced Mgr2p from the import complex leading to gating impairment. These results suggest that Mgr2p regulates the gating behavior of the TIM23 channel.

Original languageEnglish
Article number1960
JournalFrontiers in Physiology
Issue numberJAN
StatePublished - 2019


FundersFunder number
American Heart and Stroke Association18AIREA33960383, PSC-CUNY 61716-00-49
Feit Foundation
Horizon 2020 Framework Programme637649
European Research Council


    • Mgr2
    • Mitochondria
    • Protein import
    • Reactive oxygen species
    • TIM23


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