bims-cytox1 2024-04-14 papers

Issue of 2024‒04‒14
two papers selected by
Gavin McStay, Liverpool John Moores University

Int J Mol Sci. 2024 Mar 29. pii: 3814. [Epub ahead of print]25(7):

More than Just Bread and Wine: Using Yeast to Understand Inherited Cytochrome Oxidase Deficiencies in Humans.

Chenelle A Caron-Godon, Emma Collington, Jessica L Wolf, Genna Coletta, D Moira Glerum.

Inherited defects in cytochrome c oxidase (COX) are associated with a substantial subset of diseases adversely affecting the structure and function of the mitochondrial respiratory chain. This multi-subunit enzyme consists of 14 subunits and numerous cofactors, and it requires the function of some 30 proteins to assemble. COX assembly was first shown to be the primary defect in the majority of COX deficiencies 36 years ago. Over the last three decades, most COX assembly genes have been identified in the yeast Saccharomyces cerevisiae, and studies in yeast have proven instrumental in testing the impact of mutations identified in patients with a specific COX deficiency. The advent of accessible genome-wide sequencing capabilities has led to more patient mutations being identified, with the subsequent identification of several new COX assembly factors. However, the lack of genotype-phenotype correlations and the large number of genes involved in generating a functional COX mean that functional studies must be undertaken to assign a genetic variant as being causal. In this review, we provide a brief overview of the use of yeast as a model system and briefly compare the COX assembly process in yeast and humans. We focus primarily on the studies in yeast that have allowed us to both identify new COX assembly factors and to demonstrate the pathogenicity of a subset of the mutations that have been identified in patients with inherited defects in COX. We conclude with an overview of the areas in which studies in yeast are likely to continue to contribute to progress in understanding disease arising from inherited COX deficiencies.

Keywords: COX assembly; copper transfer; heme A biosynthesis; mitochondrial disease; yeast model

DOI: https://doi.org/10.3390/ijms25073814

J Exp Bot. 2024 Apr 09. pii: erae151. [Epub ahead of print]

Experimental approaches to studying translation in plant semi-autonomous organelles.

Malgorzata Kwasniak-Owczarek, Hanna Janska.

Plant mitochondria and chloroplasts are semi-autonomous organelles originated from free-living bacteria and retaining respective reduced genomes during evolution. As a consequence, relatively few of the mitochondrial and chloroplast proteins are encoded in the organellar genomes and synthesized by the organellar ribosomes. Since the both organellar genomes encode mainly components of the energy transduction systems, oxidative phosphorylation in mitochondria and photosynthetic apparatus in chloroplasts, understanding the organellar translation is critical to a thorough comprehension of the key aspects of mitochondrial and chloroplast activity affecting plant growth and development. Recent studies have clearly shown that translation is a key regulatory node in the expression of plant organellar genes, underscoring the need for an adequate methodology to study this unique stage of gene expression. The organellar translatome can be analysed by studying newly synthesized proteins or the mRNA pool recruited to the organellar ribosomes. In this review, we present in some detail the experimental approaches used to date for studying translation in the plant bioenergetic organelles. Their benefits and limitations, as well as the critical steps are discussed. Additionally, we briefly mention several recently developed strategies to study organellar translation that have not yet been applied to plants.

Keywords: Arabidopsis; chloroplast; mitochondria; plant; polysome profiling; protein synthesis; radioisotope labeling; ribosome; ribosome profiling; translation assay

DOI: https://doi.org/10.1093/jxb/erae151