bims-tricox 2026-05-17 papers

Issue of 2026–05–17
three papers selected by
Yash Verma, Universität Zürich

Mitochondrion. 2026 May 14. pii: S1567-7249(26)00054-1. [Epub ahead of print] 102164

A century of studies on mitochondrial cytochrome c oxidase.

Ulrik Pedroza-Dávila, Yolanda Camacho-Villasana, Diego González-Halphen, Xochitl Perez-Martinez.

Cytochrome c oxidase (CcO, complex IV) is the last component of the respiratory chain, catalyzing the reduction of oxygen to water and the translocation of protons to the inner membrane space. In 1925, David Keilin published his work on the rediscovery of cytochromes, including types a and a3. The same year, Otto Warburg published part of his work on the "respiratory ferment". Both articles are fundamental to bioenergetics and the mitochondrial field. Since its discovery, CcO has been the subject of study in hundreds of laboratories across the world, but there are still many interrogates to be answered. To commemorate the 100th anniversary of the publication of these two seminal works, this review examines various aspects of the history of CcO (complex IV) and the challenges yet to be resolved of this enzyme.

Keywords: Complex IV; Cytochromec oxidase; Cytochromes; History

DOI: https://doi.org/10.1016/j.mito.2026.102164

Nature. 2026 May 13.

SNOR promotes translation restart after dormancy.

Maciej Gluc, Higor Rosa, Maria Bozko, Lesley A Turner, Cassidy R Prince, Yelena Peskova, Heather A Feaga, Kathleen L Gould, Simone Mattei, Ahmad Jomaa.

Cellular dormancy enables survival during prolonged nutrient limitation by reversibly suppressing protein synthesis1-4. How inactive eukaryotic ribosomes are reactivated when nutrients return remains unclear. Here, using high-resolution in situ cryo-electron tomography in Schizosaccharomyces pombe, we identify SNOR, an SBDS domain-containing ribosome-associated factor that binds at the peptidyl transferase centre and contacts the hypusinated loop of eIF5A during glucose depletion-induced dormancy. Rather than acting as a canonical hibernation factor, SNOR licenses dormant ribosomes for rapid translational restart. Upon glucose repletion, SNOR and eIF5A act together to promote efficient recovery of polysomes and exit from dormancy. These findings define a stress-responsive ribosome restart module that couples carbon-source limitation to surveillance of the ribosomal active site and reactivation of protein synthesis.

DOI: https://doi.org/10.1038/s41586-026-10530-7

Biochim Biophys Acta Mol Cell Res. 2026 May 13. pii: S0167-4889(26)00056-X. [Epub ahead of print] 120158

Mammalian mtDNA gene expression: Concepts learned from in vivo models.

Diana Rubalcava-Gracia, Nils-Göran Larsson.

Mammalian mitochondrial DNA (mtDNA) expression is essential for oxidative phosphorylation (OXPHOS) and its in vivo regulation requires significant refinement. Here, we review key insights from mouse models carrying genetic modifications to the mtDNA expression machinery. While in vitro studies defined the basic machinery, mouse models reveal that mitochondrial transcription often exceeds immediate needs and may not be the primary rate-limiting step for OXPHOS biogenesis. Instead, mitochondria produce a transcript surplus regulated by nucleoid compaction and post-transcriptional stabilization. This apparent excess capacity is uncoupled from protein output under basal conditions but becomes critical during physiological stress or pathology. Using current and emerging genetic tools, researchers are now deciphering how regulatory layers coordinate to sustain systemic energy demands. These lessons highlight the importance of in vivo systems for identifying regulatory control points of mtDNA expression and developing targeted therapies for mitochondrial disorders.

DOI: https://doi.org/10.1016/j.bbamcr.2026.120158