mt-LAF3 is a pseudouridine synthase ortholog required for mitochondrial rRNA and mRNA gene expression in Trypanosoma brucei

• DOI: 10.1016/j.ijpara.2023.04.002
• Publication Date: 2023-06-01T08:41:20Z
• Authors: Suzanne M. McDermott; Vy Pham; Isaac Lewis; Maxwell Tracy; Kenneth Stuart
• Keywords: Pseudouridine

Trypanosoma brucei and related kinetoplastid parasites possess unique RNA processing pathways, including in their mitochondria, that regulate metabolism development. Altering composition or conformation through nucleotide modifications is one such pathway, pseudouridine fate function many organisms. We surveyed synthase (PUS) orthologs trypanosomatids, with a particular interest mitochondrial enzymes due to potential importance for metabolism. (mt)-LAF3 an ortholog of human yeast PUS enzymes, mitoribosome assembly factor, but structural studies differ conclusion as whether it has catalytic activity. Here, we generated T. cells are conditionally null (CN) mt-LAF3 expression showed loss lethal disrupts membrane (ΔΨm). Addition mutant gamma ATP allele the CN permitted ΔΨm maintenance cell survival, allowing us assess primary effects on RNAs. As expected, these dramatically decreases levels 12S 9S rRNAs. Notably, also observed mRNA levels, differential edited vs. pre-edited mRNAs, indicating required rRNA processing, transcripts. To activity mutated conserved aspartate necessary catalysis other not essential growth, levels. Together, results indicate normal mRNAs addition rRNAs, functions. Instead, our work, combined previous studies, suggests acts RNA-stabilizing scaffold.