Open AccessmRNA structural dynamics shape Argonaute-target interactions
Author(s) -
Suzan Ruijtenberg,
Stijn Sonneveld,
Tao Cui,
Ive Logister,
Dion de Steenwinkel,
Yao Xiao,
Ian J. MacRae,
Chirlmin Joo,
Marvin E. Tanenbaum
Publication year - 2020
Publication title -
nature structural and molecular biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 9.448
H-Index - 270
eISSN - 1545-9993
pISSN - 1545-9985
DOI - 10.1038/s41594-020-0461-1
Subject(s) - argonaute , microbiology and biotechnology , rna , messenger rna , ribosome , small interfering rna , biology , translation (biology) , dicer , biophysics , chemistry , biochemistry , gene
Small interfering RNAs (siRNAs) promote RNA degradation in a variety of processes and have important clinical applications. siRNAs direct cleavage of target RNAs by guiding Argonaute2 (AGO2) to its target site. Target site accessibility is critical for AGO2-target interactions, but how target site accessibility is controlled in vivo is poorly understood. Here, we use live-cell single-molecule imaging in human cells to determine rate constants of the AGO2 cleavage cycle in vivo. We find that the rate-limiting step in mRNA cleavage frequently involves unmasking of target sites by translating ribosomes. Target site masking is caused by heterogeneous intramolecular RNA-RNA interactions, which can conceal target sites for many minutes in the absence of translation. Our results uncover how dynamic changes in mRNA structure shape AGO2-target recognition, provide estimates of mRNA folding and unfolding rates in vivo, and provide experimental evidence for the role of mRNA structural dynamics in control of mRNA-protein interactions.