Dataset Information

Uridylation of miRNAs by hen1 suppressor1 in Arabidopsis.

ABSTRACT: HEN1-mediated 2'-O-methylation has been shown to be a key mechanism to protect plant microRNAs (miRNAs) and small interfering RNAs (siRNAs) as well as animal piwi-interacting RNAs (piRNAs) from degradation and 3' terminal uridylation [1-8]. However, enzymes uridylating unmethylated miRNAs, siRNAs, or piRNAs in hen1 are unknown. In this study, a genetic screen identified a second-site mutation hen1 suppressor1-2 (heso1-2) that partially suppresses the morphological phenotypes of the hypomorphic hen1-2 allele and the null hen1-1 allele in Arabidopsis. HESO1 encodes a terminal nucleotidyl transferase that prefers to add untemplated uridine to the 3' end of RNA, which is completely abolished by 2'-O-methylation. heso1-2 affects the profile of u-tailed miRNAs and siRNAs and increases the abundance of truncated and/or normal sized ones in hen1, which often results in increased total amount of miRNAs and siRNAs in hen1. In contrast, overexpressing HESO1 in hen1-2 causes more severe morphological defects and less accumulation of miRNAs. These results demonstrate that HESO1 is an enzyme uridylating unmethylated miRNAs and siRNAs in hen1. These observations also suggest that uridylation may destabilize unmethylated miRNAs through an unknown mechanism and compete with 3'-to-5' exoribonuclease activities in hen1. This study shall have implications on piRNA uridylation in hen1 in animals.

SUBMITTER: Ren G

PROVIDER: S-EPMC3582666 | biostudies-literature | 2012 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Uridylation of miRNAs by hen1 suppressor1 in Arabidopsis.

Ren Guodong G Chen Xuemei X Yu Bin B

Current biology : CB 20120329 8

HEN1-mediated 2'-O-methylation has been shown to be a key mechanism to protect plant microRNAs (miRNAs) and small interfering RNAs (siRNAs) as well as animal piwi-interacting RNAs (piRNAs) from degradation and 3' terminal uridylation [1-8]. However, enzymes uridylating unmethylated miRNAs, siRNAs, or piRNAs in hen1 are unknown. In this study, a genetic screen identified a second-site mutation hen1 suppressor1-2 (heso1-2) that partially suppresses the morphological phenotypes of the hypomorphic h ...[more]

PMID: 22464191

Similar Datasets

Project description:miRNA levels depend on both biogenesis and turnover. The methyltransferase HEN1 stabilizes plant miRNAs, animal piRNAs, and siRNAs in both kingdoms via 3' terminal methylation. Loss of HEN1 in plants results in non-templated oligo-uridylation and accelerated degradation of miRNAs. In hen1 mutants from Arabidopsis and rice, we found that the patterns of miRNA truncation and uridylation differ substantially among miRNA families, but such patterns for the same miRNA are conserved between species. miR166 and miR163 are truncated predominantly to ~17 and ~16 nt, and subsequently recover via uridylation to approximately their original sizes, 21 and 24 nt, suggesting that in these cases miRNA truncation triggers uridylation. miR171 is untruncated but uridylated to 22 nt in hen1 mutants, gaining the ability to trigger production of phased, secondary siRNAs. Truncated and tailed variants were bound by ARGONAUTE1 (AGO1) in hen1, implying that these events occur while miRNAs are still bound by AGO1. Unexpectedly, a portion of miR158 in wildtype remains unmethylated and thus subject to uridylation and destabilization, suggesting that plants naturally utilize miRNA methylation to modulate miRNA accumulation. Our results suggest that the AGO1-containing RISC complex may undergo programming to reflect each bound miRNA, determining a defined, distinct decay destiny. In this analysis, we sequenced sRNAs from two hen1 mutant alleles in Arabidopsis and three hen1 alleles in rice. In Arabidopsis, the strong hen1-1 allele in the Landsberg erecta (Ler) ecotype is the first hen1 mutant and emerged from an enhancer screen in the hua1-1/hua2-1 background, and hen1-8 in the Columbia (Col) background is a weak allele. In rice, WAVY LEAF1 (WAF1) is the ortholog of Arabidopsis HEN1, and two mutant alleles waf1-1 and waf1-2 each bear a single-base substitution leading to a premature stop codon in the second exon and a non-functional splicing site of the fourth intron, respectively. We identified a third mutant allele of the rice HEN1 gene (Oshen1-3 from the Korean (POSTEC) rice T-DNA mutant population).

Dataset Information

Uridylation of miRNAs by hen1 suppressor1 in Arabidopsis.

Publications

Uridylation of miRNAs by hen1 suppressor1 in Arabidopsis.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets