Cookies Disclaimer

OK Our site saves small pieces of text information (cookies) on your device in order to deliver better content and for statistical purposes. You can disable the usage of cookies by changing the settings of your browser. By browsing our website without changing the browser settings you grant us permission to store that information on your device.


Bibliographic Data

  • Authors: Callegari S., Müller T., Schulz C., Lenz C., Jans D.C., Wissel M., Opazo F., Rizzoli S.O., Jakobs S., Urlaub H., Rehling P., Deckers M.
  • Title: A MICOS-TIM22 Association Promotes Carrier Import into Human Mitochondria.
  • Journal: Journal of Molecular Biology
  • Volume: 431
  • Volume: 2835-2851
  • DOI: 10.1016/j.jmb.2019.05.015


Mitochondrial membrane proteins with internal targeting signals are inserted into the inner membrane by the carrier translocase (TIM22 complex). For this, precursors have to be initially directed from the TOM complex in the outer mitochondrial membrane across the intermembrane space towards the TIM22 complex. How these two translocation processes are topologically coordinated is still unresolved. Using proteomic approaches, we find that the human TIM22 complex associates with the Mitochondrial Contact site and Cristae Organizing System (MICOS) complex. This association does not appear to be conserved in yeast, whereby the yeast MICOS complex instead interacts with the presequence translocase. Using a yeast mic10Δ strain and a HEK293T MIC10 knockout cell line, we characterize the role of MICOS for protein import into the mitochondrial inner membrane and matrix. We find that a physiological cristae organization promotes efficient import via the presequence pathway in yeast, while in human mitochondria, the MICOS complex is dispensable for protein import along the presequence pathway. However, in human mitochondria the MICOS complex is required for the efficient import of carrier proteins into the mitochondrial inner membrane. Our analyses suggest that in human mitochondria, positioning of the carrier translocase at the crista junction, and potentially in vicinity to the TOM complex, is required for efficient transport into the inner membrane.