bims-tricox 2026-02-15 papers

Issue of 2026–02–15
two papers selected by
Yash Verma, Universität Zürich

Protein Sci. 2026 Mar;35(3): e70491

Mitochondrial presequences are more than just address labels.

Erik Marcel Heller, Svenja Lenhard, Doron Rapaport, Johannes Herrmann.

Most mitochondrial proteins are synthesized in the cytosol as precursor proteins with N-terminal presequences. These presequences serve as targeting signals that facilitate the binding to mitochondrial surface receptors and translocation across the mitochondrial membranes. However, recent studies showed that presequences can be more than address tags. They can contain degradation signals recognized by components of the ubiquitin-proteasome system, and therefore, serve as timers that determine the lifespan of newly synthesized precursor proteins. Moreover, presequences can interact with components of the cytosolic chaperone system to prevent or delay precursor folding. Finally, presequences of some dually localized proteins contain targeting information not only for mitochondria but also for other cellular destinations such as the nuclear lumen or chloroplasts in plant cells. Thus, presequences contain multifaceted information to endow mitochondrial precursor proteins with specific properties that are critical for the early steps of mitochondrial protein biogenesis.

Keywords: Presequence; chaperones; mitochondria; proteasome; protein import; ubiquitin ligases

DOI: https://doi.org/10.1002/pro.70491

Nat Rev Mol Cell Biol. 2026 Feb 13.

Mechanisms and disease relevance of mitochondrial translation in humans.

Ricarda Richter-Dennerlein, Xaquin Castro Dopico, Joanna Rorbach.

Human mitochondrial ribosomes (mitoribosomes) synthesize the 13 mitochondrial-encoded proteins of the oxidative phosphorylation machinery in a coordinated manner, ensuring proper folding of nascent peptides into the inner mitochondrial membrane and their dynamic assembly with nuclear-encoded oxidative phosphorylation components. Our understanding of mitochondrial translation is rapidly advancing, and in this Review, we discuss recent studies that reveal the intricate regulation of mitochondrial translation initiation, elongation and termination, ribosome biogenesis, redox sensing, mitochondrial mRNA maturation, and quality control mechanisms such as mitoribosome rescue. High-resolution structural studies, mitoribosome profiling and other innovative methodologies provide comprehensive insights into these regulatory networks. We also discuss pathological consequences of mitochondrial translation dysfunction, particularly antibiotic-induced ribosome stalling, which can have severe side effects in some individuals and therapeutic benefits in others. Relatedly, we discuss the emerging roles and clinical relevance of mitochondrial protein synthesis in cancer and immunity. Finally, we outline future directions in the field, including in vitro reconstitution of mitochondrial translation, gene editing in mitochondrial DNA and therapeutic applications.

DOI: https://doi.org/10.1038/s41580-026-00948-2