Defective RNA processing enhances RNA silencing and influences flowering of Arabidopsis

Alan J. Herr, Attila Molnar, Alex Jones, David C. Baulcombe*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

Many eukaryotic cells use RNA-directed silencing mechanisms to protect against viruses and transposons and to suppress endogenous gene expression at the posttranscriptional level. RNA silencing also is implicated in epigenetic mechanisms affecting chromosome structure and transcriptional gene silencing. Here, we describe enhanced silencing phenotype (esp) mutants in Arabidopsis thaliana that reveal how proteins associated with RNA processing and 3' end formation can influence RNA silencing. These proteins were a putative DEAH RNA helicase homologue of the yeast PRP2 RNA splicing cofactor and homologues of mRNA 3' end formation proteins CstF64, symplekin/PTA1, and CPSF100. The last two proteins physically associated with the flowering time regulator FY in the 3' end formation complex AtCPSF. The phenotypes of the Tend formation esp mutants include impaired termination of the transgene transcripts, early flowering, and enhanced silencing of the FCA-beta mRNA. Based on these findings, we propose that the ESP-containing 3' end formation complexes prevent transgene and endogenous mRNAs from entering RNA-silencing pathways. According to this proposal, in the absence of these ESP proteins, these RNAs have aberrant 3' termini. The aberrant RNAs would enter the RNA silencing pathways because they are converted into dsRNA by RNA-dependent RNA polymerases.

Original languageEnglish
Pages (from-to)14994-15001
Number of pages8
JournalProceedings of the National Academy of Sciences
Volume103
Issue number41
DOIs
Publication statusPublished - 10 Oct 2006

Keywords

  • aberrant RNA
  • polyadenylation
  • siRNAs
  • epigenetics
  • RNA polymerase
  • PRE-MESSENGER-RNA
  • BINDING-PROTEIN HYL1
  • SACCHAROMYCES-CEREVISIAE
  • CAENORHABDITIS-ELEGANS
  • POLY(A) POLYMERASE
  • SPLICING MUTANTS
  • GENE
  • VIRUS
  • PLANTS
  • YEAST

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