ABSTRACT
Mitochondria are metabolic hubs that are essential for cellular homeostasis. Most mitochondrial proteins are translated in the cytosol and imported into the organelle. However, import machineries can become overwhelmed or disrupted by physiological demands, mitochondrial damage or diseases, such as metabolic and neurodegenerative disorders. Impaired import affects mitochondrial function and causes un-imported pre-proteins to accumulate not only in the cytosol but also in other compartments, including the endoplasmic reticulum and nucleus. Quality control pathways have evolved to mitigate the accumulation of these mistargeted proteins and prevent proteotoxicity. In this Cell Science at a Glance article and the accompanying poster, we summarize the fate of un-imported mitochondrial proteins and the compartment-specific quality control pathways that regulate them.
Footnotes
Funding
The work was supported by the Natural Sciences and Engineering Research Council of Canada (RGPIN-2020-05204 to H.W.) and Michael Smith Health Research BC (SCH-2021-1524 to H.W.). M.G. was supported by the Cell and Developmental Biology (CELL) Graduate Program Fellowship. J.K. was supported by the Canadian Institutes of Health Research (Canada Graduate Scholarship, Master's Award), a University of British Columbia Graduate Scholarship, and Korean Canadian Scholarship Foundation.
High-resolution poster and poster panels
A high-resolution version of the poster and individual poster panels are available for downloading at https://journals.biologists.com/jcs/article-lookup/doi/10.1242/jcs.263757#supplementary-data.
Special Issue
This article is part of the Special Issue ‘Cell Biology of Mitochondria’, guest edited by Ana J. Garcia-Saez and Heidi McBride. See related articles at https://journals.biologists.com/jcs/issue/138/9.
