bims-mitran 2024-06-30 papers

Issue of 2024‒06‒30
two papers selected by
Andreas Kohler, Umeå University

RNA Biol. 2024 Jan;21(1): 23-30

The catalytic activity of methyltransferase METTL15 is dispensable for its role in mitochondrial ribosome biogenesis.

Christian D Mutti, Lindsey Van Haute, Michal Minczuk.

Ribosomes are large macromolecular complexes composed of both proteins and RNA, that require a plethora of factors and post-transcriptional modifications for their biogenesis. In human mitochondria, the ribosomal RNA is post-transcriptionally modified at ten sites. The N4-methylcytidine (m4C) methyltransferase, METTL15, modifies the 12S rRNA of the small subunit at position C1486. The enzyme is essential for mitochondrial protein synthesis and assembly of the mitoribosome small subunit, as shown here and by previous studies. Here, we demonstrate that the m4C modification is not required for small subunit biogenesis, indicating that the chaperone-like activity of the METTL15 protein itself is an essential component for mitoribosome biogenesis.

Keywords: Mitochondrial ribosome; chaperone; epitranscriptomics; methyltransferase; mitochondria; ribosomal RNA

DOI: https://doi.org/10.1080/15476286.2024.2369374

J Vis Exp. 2024 Jun 07.

Mitochondrial Transformation in Baker's Yeast to Study Translation and Respiratory Complex Assembly.

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

Baker´s yeast Saccharomyces cerevisiae has been widely used to understand mitochondrial biology for decades. This model has provided knowledge about essential, conserved mitochondrial pathways among eukaryotes, and fungi or yeast-specific pathways. One of the many abilities of S. cerevisiae is the capacity to manipulate the mitochondrial genome, which so far is only possible in S. cerevisiae and the unicellular algae Chlamydomonas reinhardtii. The biolistic transformation of yeast mitochondria allows us to introduce site-directed mutations, make gene rearrangements, and introduce reporters. These approaches are mainly used to understand the mechanisms of two highly coordinated processes in mitochondria: translation by mitoribosomes and assembly of respiratory complexes and ATP synthase. However, mitochondrial transformation can potentially be used to study other pathways. In the present work, we show how to transform yeast mitochondria by high-velocity microprojectile bombardment, select and purify the intended transformant, and introduce the desired mutation in the mitochondrial genome.

DOI: https://doi.org/10.3791/66856