Single amino-acid mutation in the Drosophila melanogaster ribosomal protein uL11: an insight in its transcriptional activity

Héloïse Grunchec (1) , Jérôme Deraze (1) , Delphine Dardalhon-Cuménal (2) , Valérie Ribeiro (1) , Anne Coléno-Costes (1) , Karine Dias (3) , Sébastien Bloyer (4) , Emmanuèle Mouchel-Vielh (1) , Frédérique Peronnet (2) , Hélène Thomassin (2)

1 SU - Sorbonne Université
2 CNRS - Centre National de la Recherche Scientifique
3 ENS-PSL - École normale supérieure - Paris
4 Université Paris-Saclay

ABSTRACT The ribosomal protein uL11 is located at the basis of the ribosome P-stalk and plays a paramount role in translation efficiency. In addition, no mutant for uL11 is available suggesting that this gene is haplo-insufficient as many other Ribosomal Protein Genes ( RPGs ). We have previously shown that overexpression of Drosophila melanogaster uL11 induces the transcription of many RPGs and Ribosomal Biogenesis genes ( RiBis ) suggesting that uL11 might globally regulate the level of translation through its transcriptional activity. Moreover, uL11 trimethylated on lysine 3 (uL11K3me3) interacts with the chromodomain of the Enhancer of Polycomb and Trithorax Corto. uL11, Corto and RNA Polymerase II co-localize at many sites on polytene chromosomes. These data have led to the hypothesis that the N-terminal end of uL11, and more particularly the trimethylation of lysine 3, supports the extra-ribosomal activity of uL11 in transcription. To address this question, we mutated the lysine 3 codon using a CRISPR/Cas9 strategy and obtained several lysine 3 mutants. We describe here the first mutants of D. melanogaster uL11 . Unexpectedly, the uL11 K3A allele, in which the lysine 3 codon is replaced by an alanine, displays a genuine Minute phenotype known to be characteristic of RPG deletions (longer development, low fertility, high lethality, thin and short bristles) whereas the uL11 K3Y allele, in which the lysine 3 codon is replaced by a tyrosine, is unaffected. In agreement, the translation rate slightly decreases in uL11 K3A but not in uL11 K3Y . Deep-sequencing of RNA from wing imaginal discs shows enrichment in the GO categories “glutathione metabolism” for up-regulated genes in both mutants and “regulation of transcription” for down-regulated genes in uL11 K3A . Furthermore, analysis of deregulated genes’ cis -regulatory sequences suggests that uL11 might regulate transcription of target genes in concert with the couple of transcription factors Mad/Med that mediate response to the Bone Morphogenetic Protein (BMP) signaling pathway.

Mots clés: development; ribosomal protein; transcription; drosophila

Domaines: Biologie du développement

Héloïse Grunchec, Jérôme Deraze, Delphine Dardalhon-Cuménal, Valérie Ribeiro, Anne Coléno-Costes, et al.. Single amino-acid mutation in the Drosophila melanogaster ribosomal protein uL11: an insight in its transcriptional activity. 2021. ⟨hal-03453229⟩