PUBLICATION
Translational inhibition by deadenylation-independent mechanisms is central to microRNA-mediated silencing in zebrafish
- Authors
- Mishima, Y., Fukao, A., Kishimoto, T., Sakamoto, H., Fujiwara, T., and Inoue, K.
- ID
- ZDB-PUB-120111-40
- Date
- 2012
- Source
- Proceedings of the National Academy of Sciences of the United States of America 109(4): 1104-1109 (Journal)
- Registered Authors
- Inoue, Kunio, Kishimoto, Tomoyoshi, Mishima, Yuichiro
- Keywords
- none
- MeSH Terms
-
- Blotting, Western
- Luciferases
- Zebrafish Proteins/genetics*
- Zebrafish Proteins/metabolism
- Autoantigens/genetics*
- PubMed
- 22232654 Full text @ Proc. Natl. Acad. Sci. USA
Abstract
MicroRNA (miRNA) is a class of small noncoding RNA approximately 22 nt in length. Animal miRNA silences complementary mRNAs via translational inhibition, deadenylation, and mRNA degradation. However, the underlying molecular mechanisms remain unclear. A key question is whether these three outputs are independently induced by miRNA through distinct mechanisms or sequentially induced within a single molecular pathway. Here, we successfully dissected these intricate outputs of miRNA-mediated repression using zebrafish embryos as a model system. Our results indicate that translational inhibition and deadenylation are independent outputs mediated by distinct domains of TNRC6A, which is an effector protein in the miRNA pathway. Translational inhibition by TNRC6A is divided into two mechanisms: PAM2 motif-mediated interference of poly(A)-binding protein (PABP), and inhibition of 52 cap- and poly(A) tail-independent step(s) by a previously undescribed P-GL motif. Consistent with these observations, we show that, in zebrafish embryos, miRNA inhibits translation of the target mRNA in a deadenylation- and PABP-independent manner at early time points. These results indicate that miRNA exerts multiple posttranscriptional outputs via physically and functionally independent mechanisms and that direct translational inhibition is central to miRNA-mediated repression.
Genes / Markers
Figure Gallery (11 images)
/ 2
/ 2
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Orthology
Engineered Foreign Genes
Mapping