title: Surveillance of 3' Noncoding Transcripts Requires FIERY1 and XRN3 in Arabidopsis.
abstract: Eukaryotes possess several RNA surveillance mechanisms that prevent undesirable aberrant RNAs from accumulating. Arabidopsis XRN2, XRN3, and XRN4 are three orthologs of the yeast 5'-to-3' exoribonuclease, Rat1/Xrn2, that function in multiple RNA decay pathways. XRN activity is maintained by FIERY1 (FRY1), which converts the XRN inhibitor, adenosine 3', 5'-bisphosphate (PAP), into 5'AMP. To identify the roles of XRNs and FRY1 in suppression of non-coding RNAs, strand-specific genome-wide tiling arrays and deep strand-specific RNA-Seq analyses were carried out in fry1 and xrn single and double mutants. In fry1-6, about 2000 new transcripts were identified that extended the 3' end of specific mRNAs; many of these were also observed in genotypes that possess the xrn3-3 mutation, a partial loss-of-function allele. Mutations in XRN2 and XRN4 in combination with xrn3-3 revealed only a minor effect on 3' extensions, indicating that these genes may be partially redundant with XRN3. We also observed the accumulation of 3' remnants of many DCL1-processed microRNA (miRNA) precursors in fry1-6 and xrn3-3. These findings suggest that XRN3, in combination with FRY1, is required to prevent the accumulation of 3' extensions that arise from thousands of mRNA and miRNA precursor transcripts.
authors.forename: Yukio
authors.initials: Y
authors.lastname: Kurihara
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Schmitz
authors.forename: Joseph R
authors.initials: JR
authors.lastname: Nery
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Schultz
authors.forename: Emiko
authors.initials: E
authors.lastname: Okubo-Kurihara
authors.forename: Taeko
authors.initials: T
authors.lastname: Morosawa
authors.forename: Maho
authors.initials: M
authors.lastname: Tanaka
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Toyoda
authors.forename: Motoaki
authors.initials: M
authors.lastname: Seki
authors.forename: Joseph R
authors.initials: JR
authors.lastname: Ecker