An mTRAN-mRNA interaction mediates mitochondrial translation initiation in plants.

Tran HC, Schmitt V, Lama S, Wang C, Launay-Avon A, Bernfur K, Sultan K, Khan K, Brunaud V, Liehrmann A, Castandet B, Levander F, Rasmusson AG, Mireau H, Delannoy E, Van Aken O

Science 381 (6661) eadg0995 [2023-09-00; online 2023-09-01]

Plant mitochondria represent the largest group of respiring organelles on the planet. Plant mitochondrial messenger RNAs (mRNAs) lack Shine-Dalgarno-like ribosome-binding sites, so it is unknown how plant mitoribosomes recognize mRNA. We show that "mitochondrial translation factors" mTRAN1 and mTRAN2 are land plant-specific proteins, required for normal mitochondrial respiration chain biogenesis. Our studies suggest that mTRANs are noncanonical pentatricopeptide repeat (PPR)-like RNA binding proteins of the mitoribosomal "small" subunit. We identified conserved Adenosine (A)/Uridine (U)-rich motifs in the 5' regions of plant mitochondrial mRNAs. mTRAN1 binds this motif, suggesting that it is a mitoribosome homing factor to identify mRNAs. We demonstrate that mTRANs are likely required for translation of all plant mitochondrial mRNAs. Plant mitochondrial translation initiation thus appears to use a protein-mRNA interaction that is divergent from bacteria or mammalian mitochondria.

Bioinformatics Support and Infrastructure [Collaborative]

Bioinformatics Support, Infrastructure and Training [Collaborative]

PubMed 37651534

DOI 10.1126/science.adg0995

Crossref 10.1126/science.adg0995

Publications 9.5.0