Pimet, the Drosophila homolog of HEN1, mediates 2′-O-methylation of Piwi-interacting RNAs at their 3′ ends

Kuniaki Saito, Yuriko Sakaguchi, Takeo Suzuki, Tsutomu Suzuki, Haruhiko Siomi, Mikiko C. Siomi

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288 Citations (Scopus)


Piwi-interacting RNAs (piRNAs) consist of a germline-specific group of small RNAs derived from distinct intergenic loci in the genome. piRNAs function in silencing selfish transposable elements through binding with the PIWI subfamily proteins of Argonautes. Here we show that piRNAs in Drosophila are 2′-O-methylated at their 3′ ends. Loss of Pimet (piRNA methyltransferase), the Drosophila homolog of Arabidopsis HEN1 methyltransferase for microRNAs (miRNAs), results in loss of 2′-O-methylation of fly piRNAs. Recombinant Pimet shows single-stranded small RNA methylation activity in vitro and interacts with the PIWI proteins within Pimet mutant ovary. These results show that Pimet mediates piRNA 2′-O-methylation in Drosophila.

Original languageEnglish
Pages (from-to)1603-1608
Number of pages6
JournalGenes and Development
Issue number13
Publication statusPublished - 2007 Jul 1



  • 2′-O-methylation
  • Drosophila
  • HEN1
  • Pimet
  • piRNA

ASJC Scopus subject areas

  • Genetics
  • Developmental Biology

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