Mutations in Conserved Residues of the C. elegans microRNA Argonaute ALG-1 Identify Separable Functions in ALG-1 miRISC Loading and Target Repression

Zinovyeva, A. Y., Bouasker, S., Simard, M. J., Hammell, C. M., Ambros, V. (April 2014) Mutations in Conserved Residues of the C. elegans microRNA Argonaute ALG-1 Identify Separable Functions in ALG-1 miRISC Loading and Target Repression. PLoS Genetics, 10 (4). e1004286. ISSN 1553-7404 (Electronic)1553-7390 (Linking)

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URL: http://www.ncbi.nlm.nih.gov/pubmed/24763381
DOI: 10.1371/journal.pgen.1004286

Abstract

microRNAs function in diverse developmental and physiological processes by regulating target gene expression at the post-transcriptional level. ALG-1 is one of two Caenorhabditis elegans Argonautes (ALG-1 and ALG-2) that together are essential for microRNA biogenesis and function. Here, we report the identification of novel antimorphic (anti) alleles of ALG-1 as suppressors of lin-28(lf) precocious developmental phenotypes. The alg-1(anti) mutations broadly impair the function of many microRNAs and cause dosage-dependent phenotypes that are more severe than the complete loss of ALG-1. ALG-1(anti) mutant proteins are competent for promoting Dicer cleavage of microRNA precursors and for associating with and stabilizing microRNAs. However, our results suggest that ALG-1(anti) proteins may sequester microRNAs in immature and functionally deficient microRNA Induced Silencing Complexes (miRISCs), and hence compete with ALG-2 for access to functional microRNAs. Immunoprecipitation experiments show that ALG-1(anti) proteins display an increased association with Dicer and a decreased association with AIN-1/GW182. These findings suggest that alg-1(anti) mutations impair the ability of ALG-1 miRISC to execute a transition from Dicer-associated microRNA processing to AIN-1/GW182 associated effector function, and indicate an active role for ALG/Argonaute in mediating this transition.

Item Type: Paper
Subjects: organism description > animal > C elegans
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types > argonaute proteins
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > DNA, RNA structure, function, modification > miRNA
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > DNA, RNA structure, function, modification > miRNA
CSHL Authors:
Communities: CSHL Cancer Center Program > Cancer Genetics
CSHL Cancer Center Shared Resources > Bioinformatics Service
CSHL labs > Hammell C. lab
CSHL Cancer Center Shared Resources > DNA Sequencing Service
Depositing User: Matt Covey
Date: 24 April 2014
Date Deposited: 19 Dec 2014 17:39
Last Modified: 05 Nov 2015 15:53
PMCID: PMC3998888
Related URLs:
URI: https://repository.cshl.edu/id/eprint/30974

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