RT Journal Article
SR Electronic
T1 Mistargeting of hydrophobic mitochondrial proteins activates a nucleus-mediated posttranscriptional quality control pathway in trypanosomes
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2021.08.13.456187
DO 10.1101/2021.08.13.456187
A1 Caroline E. Dewar
A1 Silke Oeljeklaus
A1 Jan Mani
A1 Wignand W. D. Mühlhäuser
A1 Bettina Warscheid
A1 André Schneider
YR 2021
UL http://biorxiv.org/content/early/2021/08/13/2021.08.13.456187.abstract
AB Mitochondrial protein import in the parasitic protozoan Trypanosoma brucei is mediated by the atypical outer membrane translocase, ATOM. It consists of seven subunits including ATOM69, the import receptor for hydrophobic proteins. Ablation of ATOM69, but not of any other subunit, triggers a unique quality control pathway resulting in the proteasomal degradation of non-imported mitochondrial proteins. The process requires a protein of unknown function, an E3 ubiquitin ligase and the ubiquitin-like protein (TbUbL1), which all are recruited to the mitochondrion upon ATOM69 depletion. TbUbL1 is a nuclear protein, a fraction of which is released to the cytosol upon triggering of the pathway. Nuclear release is essential as cytosolic TbUbL1 can bind mislocalised mitochondrial proteins and likely transfers them to the proteasome. Mitochondrial quality control has previously been studied in yeast and metazoans. Finding such a pathway in the highly diverged trypanosomes suggests such pathways are an obligate feature of all mitochondria.Competing Interest StatementThe authors have declared no competing interest.