Authors
Caroline A Spike, Micah D Gearhart, Katherine M Walstrom, Mark E Zweifel, Naomi Courtemanche, David Greenstein
Published in
bioRxiv : the preprint server for biology. Sep 25, 2026. Epub Sep 25, 2026.
Abstract
MicroRNAs have been likened to the "dark matter" of eukaryotic genomes, reflecting their pervasive regulatory influence. MicroRNAs were first identified through genetic studies of developmental timing in the nematode Caenorhabditis elegans . Let-7 was the first microRNA recognized to be broadly conserved. The principal target of Let-7 in the developmental timing pathway is the TRIM-NHL RNA-binding protein LIN-41. During the L4 larval stage, Let-7 represses lin-41 translation by binding to two Let-7 complementary sites in the lin-41 3'UTR. Despite the importance of microRNA-based translational regulation, the underlying molecular mechanisms are incompletely understood. Through genetic analysis, we discovered an unrecognized feature of the mechanism by which Let-7 controls lin-41 translation. This mechanism requires a 5'-regulatory exon containing a seven-amino acid upstream open reading frame (uORF) and conserved sequence elements. Genome editing indicates that the specific uORF amino acid sequence itself is not important. Our data suggest that uORF translation and 5'UTR structure limit initiation at the downstream lin-41 start codon, enabling tight control by Let-7. Without this mechanism, the Let-7 microRNA is unable to properly regulate lin-41 to enable proper development.
This study reports the discovery that tight control of lin-41 translation by the Let-7 microRNA in C. elegans requires a 5'-regulatory exon containing a small upstream open reading frame.
PMID:
42818256
Bibliographic data and abstract were imported from PubMed on 01 Oct 2026.
Read full publication at:
Please sign in
to see all details.
Advertisement
Stats
- Recommendations n/a n/a positive of 0 vote(s)
- Views 12
- Comments 0