Document Type
Article
Publication Date
5-2-2017
Department
Department of Biological Sciences
Abstract
RNA-induced silencing complex (RISC) is composed of miRNAs and AGO proteins. AGOs use miRNAs as guides to slice target mRNAs to produce truncated 5’ and 3’ RNA fragments. The 5’ cleaved RNA fragments are marked with uridylation for degradation. Here, we identified novel cofactors of Arabidopsis AGOs, named RICE1 and RICE2. RICE proteins specifically degraded single-strand (ss) RNAs in vitro; but neither miRNAs nor miRNA*s in vivo. RICE1 exhibited a DnaQ-like exonuclease fold and formed a homohexamer with the active sites located at the interfaces between RICE1 subunits. Notably, ectopic expression of catalytically-inactive RICE1 not only significantly reduced miRNA levels; but also increased 5’ cleavage RISC fragments with extended uridine tails. We conclude that RICEs act to degrade uridylated 5’ products of AGO cleavage to maintain functional RISC. Our study also suggests a possible link between decay of cleaved target mRNAs and miRNA stability in RISC.
Publication Title
eLife
Recommended Citation
Zhang, Z.,
Hu, F.,
Sung, M.,
Shu, C.,
Castillo-González, C.,
Koiwa, H.,
Tang, G.,
Dickman, M.,
Li, P.,
&
Zhang, X.
(2017).
RISC-interacting clearing 3’- 5’ exoribonucleases (RICES) degrade uridylated cleavage fragments to maintain functional RISC in Arabidopsis thaliana.
eLife,
6.
http://doi.org/10.7554/eLife.24466
Retrieved from: https://digitalcommons.mtu.edu/michigantech-p/3274
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Version
Publisher's PDF
Publisher's Statement
© Zhang et al. Publisher’s version of record: https://doi.org/10.7554/eLife.24466