bims-mitpro Biomed News
on Mitochondrial proteostasis
Issue of 2025–11–09
three papers selected by
Andreas Kohler, Umeå University



  1. Geroscience. 2025 Nov 04.
      Non-lethal exposure to mitochondrial stress has been shown to have beneficial effects due to activation of signaling pathways, including the mitochondrial unfolded protein response (UPRmt). Activation of UPRmt restores the function of the mitochondria and improves general health and longevity in multiple model systems, termed mitohormesis. In C. elegans, mitohormesis can be accomplished by electron transport chain inhibition, a decline in mitochondrial translation, decreased mitochondrial import, and numerous other methods that activate UPRmt. However, not all methods that activate UPRmt promote longevity. These and other studies have started to question whether UPRmt is directly correlated with longevity. Here, we attempt to address this controversy by unraveling the complex molecular regulation of longevity of the nematode under different mitochondrial stressors that induce mitochondrial stress by performing RNA sequencing to profile transcriptome changes. Using this comprehensive and unbiased approach, we aim to determine whether specific transcriptomic changes can reveal a correlation between UPRmt and longevity. Altogether, this study will provide mechanistic insights on mitohormesis and how it correlates with the lifespan of C. elegans.
    Keywords:  Aging; Caenorhabditis elegans; Mitohormesis; UPRmt
    DOI:  https://doi.org/10.1007/s11357-025-01912-2
  2. Biol Direct. 2025 Nov 06. 20(1): 108
      
    Keywords:  Biomolecular condensate; Galectin-3; Liquid-liquid phase separation (LLPS); Mitochondrial outer membrane (OMM) rupture ; PINK1/Parkin-dependent mitophagy
    DOI:  https://doi.org/10.1186/s13062-025-00692-1
  3. Mol Cell. 2025 Nov 06. pii: S1097-2765(25)00853-6. [Epub ahead of print]
      Cytosolic translation activity is fine-tuned by environmental conditions primarily through signaling pathways that target translation initiation factors. Although mitochondria possess their own translation machinery, they lack an autonomous signaling network analogous to their cytosolic counterpart for regulating translation activity. Consequently, our understanding of how mitochondrial translation activity is adjusted under different metabolic environments remains very limited. Here, we report a noncanonical mechanism for regulating mitochondrial translation activity via metabolism-dependent changes in the mitochondrial ribosome (mitoribosome) in S. cerevisiae. These changes arise from a metabolism-modulated mitoribosome assembly pathway that regulates the composition and conformation of the mitoribosome, thereby adjusting its translation activity to meet metabolic demands. Moreover, the translation activity of the mitoribosome feeds back to regulate the biogenesis of nuclear-encoded mitochondrial proteins, influencing mitochondrial functions and aging. Such a ribosomal remodeling-based "gear-switching" mechanism represents an orthogonal mode of translation regulation, compensating for the absence of a translation-modulating signaling network within mitochondria.
    Keywords:  aging; metabolism; mitochondria; mitoribosome; translation activity
    DOI:  https://doi.org/10.1016/j.molcel.2025.10.012