Article
 

The ERI-6/7 Helicase Acts at the First Stage of an siRNA Amplification Pathway That Targets Recent Gene Duplications

Public Deposited

Downloadable Content

Download PDF
https://ir.library.oregonstate.edu/concern/articles/m900nv13r

Descriptions

Attribute NameValues
Creator
Abstract
  • Endogenous small interfering RNAs (siRNAs) are a class of naturally occuring regulatory RNAs found in fungi, plants, and animals. Some endogenous siRNAs are required to silence transposons or function in chromosome segregation; however, the specific roles of most endogenous siRNAs are unclear. The helicase gene eri-6/7 was identified in the nematode Caenorhabditis elegans by the enhanced response to exogenous double-stranded RNAs (dsRNAs) of the null mutant. eri-6/7 encodes a helicase homologous to small RNA factors Armitage in Drosophila, SDE3 in Arabidopsis, and Mov10 in humans. Here we show that eri-6/7 mutations cause the loss of 26-nucleotide (nt) endogenous siRNAs derived from genes and pseudogenes in oocytes and embryos, as well as deficiencies in somatic 22-nucleotide secondary siRNAs corresponding to the same loci. About 80 genes are eri-6/7 targets that generate the embryonic endogenous siRNAs that silence the corresponding mRNAs. These 80 genes share extensive nucleotide sequence homology and are poorly conserved, suggesting a role for these endogenous siRNAs in silencing of and thereby directing the fate of recently acquired, duplicated genes. Unlike most endogenous siRNAs in C. elegans, eri-6/7–dependent siRNAs require Dicer. We identify that the eri-6/7–dependent siRNAs have a passenger strand that is ~19 nt and is inset by ~3–4 nts from both ends of the 26 nt guide siRNA, suggesting non-canonical Dicer processing. Mutations in the Argonaute ERGO-1, which associates with eri-6/7–dependent 26 nt siRNAs, cause passenger strand stabilization, indicating that ERGO-1 is required to separate the siRNA duplex, presumably through endonucleolytic cleavage of the passenger strand. Thus, like several other siRNA–associated Argonautes with a conserved RNaseH motif, ERGO-1 appears to be required for siRNA maturation.
License
Resource Type
DOI
Date Available
Date Issued
Citation
  • Fischer SEJ, Montgomery TA, Zhang C, Fahlgren N, Breen PC, et al. (2011) The ERI-6/7 Helicase Acts at the First Stage of an siRNA Amplification Pathway That Targets Recent Gene Duplications. PLoS Genetics 7(11): e1002369. doi:10.1371/journal.pgen.1002369
Journal Title
Journal Volume
  • 7
Journal Issue/Number
  • 11
Academic Affiliation
Non-Academic Affiliation
Rights Statement
Funding Statement (additional comments about funding)
  • This work was supported by National Institutes of Health Grant GM44619 (to GR) and Massachusetts General Hospital Executive Committee of Research Fund for Medical Discovery fellowship awards (to CZ and SEJF). TAM is supported by Damon Runyon Cancer Research Foundation Grant DRG-2029-09.
Publisher
Peer Reviewed
Language
Replaces

Relationships

Parents:

This work has no parents.

In Collection:

Items

Thumbnail Title Date Uploaded Visibility Actions
file details CarringtonJamesBotanyPlantPathologyERIHelicaseActs.pdf 2017-07-10 Public Download