RRC ID 45829
Author Phillips CM, Montgomery BE, Breen PC, Roovers EF, Rim YS, Ohsumi TK, Newman MA, van Wolfswinkel JC, Ketting RF, Ruvkun G, Montgomery TA.
Title MUT-14 and SMUT-1 DEAD box RNA helicases have overlapping roles in germline RNAi and endogenous siRNA formation.
Journal Curr Biol
Abstract More than 2,000 C. elegans genes are targeted for RNA silencing by the mutator complex, a specialized small interfering RNA (siRNA) amplification module which is nucleated by the Q/N-rich protein MUT-16. The mutator complex localizes to Mutator foci adjacent to P granules at the nuclear periphery in germ cells. Here, we show that the DEAD box RNA helicase smut-1 functions redundantly in the mutator pathway with its paralog mut-14 during RNAi. Mutations in both smut-1 and mut-14 also cause widespread loss of endogenous siRNAs. The targets of mut-14 and smut-1 largely overlap with the targets of other mutator class genes; however, the mut-14 smut-1 double mutant and the mut-16 mutant display the most dramatic depletion of siRNAs, suggesting that they act at a similarly early step in siRNA formation. mut-14 and smut-1 are predominantly expressed in the germline and, unlike other mutator class genes, are specifically required for RNAi targeting germline genes. A catalytically inactive, dominant-negative missense mutant of MUT-14 is RNAi defective in vivo; however, mutator complexes containing the mutant protein retain the ability to synthesize siRNAs in vitro. The results point to a role for mut-14 and smut-1 in initiating siRNA amplification in germ cell Mutator foci, possibly through the recruitment or retention of target mRNAs.
Volume 24(8)
Pages 839-44
Published 2014-4-14
DOI 10.1016/j.cub.2014.02.060
PII S0960-9822(14)00261-9
PMID 24684932
PMC PMC4010136
MeSH Animals Base Sequence Caenorhabditis elegans / genetics Caenorhabditis elegans / metabolism* Caenorhabditis elegans Proteins / genetics* Caenorhabditis elegans Proteins / metabolism DEAD-box RNA Helicases / metabolism* Fluoroimmunoassay Germ Cells / enzymology* Germ Cells / physiology Immunoprecipitation Molecular Sequence Data RNA Interference / physiology* RNA, Small Interfering / biosynthesis* Real-Time Polymerase Chain Reaction Saccharomyces cerevisiae Sequence Alignment Sequence Analysis, DNA
IF 9.601
Times Cited 22
C.elegans tm1301 tm1358