bims-tricox 2025-10-05 papers

Issue of 2025–10–05
three papers selected by
Yash Verma, University of Zurich

Trends Biochem Sci. 2025 Oct 02. pii: S0968-0004(25)00222-1. [Epub ahead of print]

Interconnectivity of mitochondrial protein biogenesis and quality control.

Abi S Ghifari, Carmela Vazquez-Calvo, Andreas Carlström, Martin Ott.

Mitochondrial protein homeostasis (proteostasis) keeps the mitochondrial proteome functional. Thus, proteostasis is essential for mitochondrial activity and overall cellular functions, and a reduction in its function corresponds with diseases and aging in humans. Recent studies in various model organisms highlight components and mechanisms of mitochondrial proteostasis from biogenesis, through assembly, to turnover. Key findings include the identification of new components and mechanistic insights into protein import and mitochondrial translation processes, the interconnectivity of protein biogenesis and quality control, and proteolytic degradation machineries. In this review we discuss these advances that improve our current understanding of the inner workings and significance of the mitochondrial proteostasis network in maintaining functional mitochondria.

Keywords: mitochondria; proteases; protein import; proteolysis; proteostasis; translation

DOI: https://doi.org/10.1016/j.tibs.2025.09.004

Curr Opin Plant Biol. 2025 Sep 27. pii: S1369-5266(25)00105-0. [Epub ahead of print]88 102791

Plant ribosomopathies: New insights and a critical re-evaluation of ribosomal protein gene mutants in plants.

Ryan E Martinez, Katherine A Klimpel, Michael Busche, Jacob O Brunkard.

Ribosomes are essential cellular machines that translate genetic information into functional proteins. Ribosomes require massive nutrient investments, accounting for as much as 50 % of organic phosphorus and 25 % of organic nitrogen in leaves. Optimizing ribosome levels could therefore reduce crop plant fertilizer requirements, an urgent goal for agricultural sustainability. Disruptions to ribosome biogenesis often cause surprising developmental defects, however, and there is substantial confusion and debate among plant geneticists about how to interpret mutant phenotypes caused by defective ribosomes. Here, we propose to adopt the conceptual framework of "ribosomopathies", human disorders caused by defects in ribosome biogenesis, to better appreciate why some plant developmental processes are more sensitive to ribosome levels than others. We argue that understanding plant ribosomopathies as a broad class of mutants that affect ribosome homeostasis, rather than a series of distinct cases impacting specialized, heterogeneous ribosomes, will encourage productive mechanistic studies of specific ribosome-sensitive developmental processes that could be engineered to circumvent the deleterious effects of restricting ribosome availability.

Keywords: Gene paralogy; Plant development; Ribosome heterogeneity; Ribosomes; Ribosomopathies; TARGET OF RAPAMYCIN; Translation

DOI: https://doi.org/10.1016/j.pbi.2025.102791

Mol Cell. 2025 Oct 02. pii: S1097-2765(25)00753-1. [Epub ahead of print]85(19): 3551-3553

And now for something completely different in co-translational targeting.

Yury S Bykov.

In two recent papers in Cell, Zhu et al.1 and Luo et al.2 use selective ribosome profiling to identify the substrates and timing of co-translational protein targeting to mitochondria. The results suggest a mechanism that is very different from the classic ER signal-recognition-particle pathway.

DOI: https://doi.org/10.1016/j.molcel.2025.09.012