title: A member of the polymerase beta nucleotidyltransferase superfamily is required for RNA interference in C. elegans.
abstract: RNA interference (RNAi) is an ancient, highly conserved mechanism in which small RNA molecules (siRNAs) guide the sequence-specific silencing of gene expression . Several silencing machinery protein components have been identified, including helicases, RNase-related proteins, double- and single-stranded RNA binding proteins, and RNA-dependent RNA polymerase-related proteins . Work on these factors has led to the revelation that RNAi mechanisms intersect with cellular pathways required for development and fertility . Despite rapid progress in understanding key steps in the RNAi pathway, it is clear that many factors required for both RNAi and related developmental mechanisms have not yet been identified. Here, we report the characterization of the C. elegans gene rde-3. Genetic analysis of presumptive null alleles indicates that rde-3 is required for siRNA accumulation and for efficient RNAi in all tissues, and it is essential for fertility and viability at high temperatures. RDE-3 contains conserved domains found in the polymerase beta nucleotidyltransferase superfamily, which includes conventional poly(A) polymerases, 2'-5' oligoadenylate synthetase (OAS), and yeast Trf4p . These findings implicate a new enzymatic modality in RNAi and suggest possible models for the role of RDE-3 in the RNAi mechanism.
authors.affiliation: Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA.
authors.forename: Chun-Chieh G
authors.initials: CC
authors.lastname: Chen
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Simard
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Tabara
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Brownell
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: McCollough
authors.forename: Craig C
authors.initials: CC
authors.lastname: Mello
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D017173:Caenorhabditis elegans / Q000235:genetics / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism*; D017931:DNA Primers; D005298:Fertility / Q000235:genetics; D040461:Gene Components; D008954:Models, Biological; D008969:Molecular Sequence Data; D009713:Nucleotidyltransferases / Q000235:genetics / Q000378:metabolism*; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA
chemical_list: D029742:Caenorhabditis elegans Proteins; D017931:DNA Primers; D034741:RNA, Small Interfering; D009713:Nucleotidyltransferases; C500385:mut-2 protein, C elegans