bims-tricox 2024-01-21 papers

Issue of 2024–01–21
two papers selected by
Yash Verma, University of Zurich

Acta Naturae. 2023 Oct-Dec;15(4):15(4): 75-82

Testing a Hypothesis of 12S rRNA Methylation by Putative METTL17 Methyltransferase.

A V Mashkovskaia, S S Mariasina, M V Serebryakova, M P Rubtsova, O A Dontsova, P V Sergiev.

Mitochondrial ribosome assembly is a complex multi-step process involving many additional factors. Ribosome formation differs in various groups of organisms. However, there are universal steps of assembly and conservative factors that have been retained in evolutionarily distant taxa. METTL17, the object of the current study, is one of these conservative factors involved in mitochondrial ribosome assembly. It is present in both bacteria and the mitochondria of eukaryotes, in particular mice and humans. In this study, we tested a hypothesis of putative METTL17 methyltransferase activity. MALDI-TOF mass spectrometry was used to evaluate the methylation of a putative METTL17 target - a 12S rRNA region interacting with METTL17 during mitochondrial ribosome assembly. The investigation of METTL17 and other mitochondrial ribosome assembly factors is of both fundamental and practical significance, because defects in mitochondrial ribosome assembly are often associated with human mitochondrial diseases.

Keywords: MALDI-TOF mass spectrometry; RNA methylation; methyltransferases; mitochondrial ribosome; ribosome assembly factors

DOI: https://doi.org/10.32607/actanaturae.25441

iScience. 2024 Jan 19. 27(1): 108767

A fast method to distinguish between fermentative and respiratory metabolisms in single yeast cells.

Laura Luzia, Julius Battjes, Emile Zwering, Derek Jansen, Chrats Melkonian, Bas Teusink.

Saccharomyces cerevisiae adjusts its metabolism based on nutrient availability, typically transitioning from glucose fermentation to ethanol respiration as glucose becomes limiting. However, our understanding of the regulation of metabolism is largely based on population averages, whereas nutrient transitions may cause heterogeneous responses. Here we introduce iCRAFT, a method that couples the ATP Förster resonance energy transfer (FRET)-based biosensor yAT1.03 with Antimycin A to differentiate fermentative and respiratory metabolisms in individual yeast cells. Upon Antimycin A addition, respiratory cells experienced a sharp decrease of the normalized FRET ratio, while respiro-fermentative cells showed no response. Next, we tracked changes in metabolism during the diauxic shift of a glucose pre-grown culture. Following glucose exhaustion, the entire cell population experienced a progressive rise in cytosolic ATP produced via respiration, suggesting a gradual increase in respiratory capacity. Overall, iCRAFT is a robust tool to distinguish fermentation from respiration, offering a new single-cell opportunity to study yeast metabolism.

Keywords: Cell biology; Microbial biotechnology

DOI: https://doi.org/10.1016/j.isci.2023.108767