Sudestada1, a Drosophila ribosomal prolyl-hydroxylase required for mRNA translation, cell homeostasis, and organ growth

Significance Emerging evidence indicates that posttranslational hydroxylation of intracellularly localized proteins is more prevalent than once thought. We identify Drosophila melanogaster sudestada1 (sud1) as a gene that is needed for normal growth in the fly and show that sud1 encodes a prolyl-hydroxylase that catalyzes posttranslational hydroxylation of a conserved residue in the small ribosomal subunit protein RPS23. Knockdown of Sud1 results in growth impairment and reduced RPS23 hydroxylation, which is associated with activation of the unfolded protein response, induction of apoptosis, and increased autophagy. Together with findings in humans and yeast reported in the companion articles, the work reveals a new type of posttranslational ribosome modification that is highly conserved in eukaryotes.