Letter | Published:

Arginine methylation of Piwi proteins catalysed by dPRMT5 is required for Ago3 and Aub stability

Nature Cell Biology volume 11, pages 652658 (2009) | Download Citation



Piwi family proteins are essential for germline development and bind piwi-interacting RNAs (piRNAs)1,2,3. The grandchildless gene aub of Drosophila melanogaster encodes the piRNA-binding protein Aubergine (Aub), which is essential for formation of primordial germ cells (PGCs)4. Here we report that Piwi family proteins of mouse, Xenopus laevis and Drosophila contain symmetrical dimethylarginines (sDMAs). We found that Piwi proteins are expressed in Xenopus oocytes and we identified numerous Xenopus piRNAs. We report that the Drosophila homologue of protein methyltransferase 5 (dPRMT5, csul/dart5), which is also the product of a grandchildless gene5,6, is required for arginine methylation of Drosophila Piwi, Ago3 and Aub proteins in vivo. Loss of dPRMT5 activity led to a reduction in the levels of piRNAs, Ago3 and Aub proteins, and accumulation of retrotransposons in the Drosophila ovary. Our studies explain the relationship between aub and dPRMT5 (csul/dart5) genes by demonstrating that dPRMT5 is the enzyme that methylates Aub. Our findings underscore the significance of sDMA modification of Piwi proteins in the germline and suggest an interacting pathway of genes that are required for piRNA function and PGC specification.

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We are grateful to M.C. Siomi, H. Siomi, K. Saito, G. Dreyfuss for antibodies; to J. Anne for csul flies; to S. Kuramochi-Miyagawa and T. Nakano for Miwi and Mili cDNA constructs; to Rebecca Beerman for help with fly methodology; to Y. Kawamura for immunofluorescence protocols and to members of the Mourelatos lab for discussions. Mass spectrometry was performed at the Proteomics Core Facility (University of Pennsylvania) and at the Proteomics Resource of the Keck Foundation (Yale University). Illumina sequencing was performed at the Functional Genomics Core of the University of Pennsylvania. Protein production was at the Protein Expression Core of the Wistar Institute. We apologize to colleagues whose studies were not cited because of space limitations. This work was supported by a Human Frontier Science Program Long Term Fellowship to Y.K., and NIH grants to T.A.J. (NS046573), P.S.K. (GM76621) and Z.M.(GM0720777, NS056070, UL1RR024134). Z.M. also received ITMAT-PENN and URF-PENN.

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  1. Department of Pathology and Laboratory Medicine, Division of Neuropathology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA.

    • Yohei Kirino
    • , Namwoo Kim
    • , Mariàngels de Planell-Saguer
    • , Eugene Khandros
    •  & Zissimos Mourelatos
  2. Department of Genetics, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA.

    • Stephanie Chiorean
    •  & Thomas A. Jongens
  3. Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA.

    • Peter S. Klein
  4. Department of Cell and Developmental Biology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA.

    • Peter S. Klein
  5. Bioinformatics and Pattern Discovery Group, IBM TJ Watson Research Center, Yorktown Heights, NY 10598, USA.

    • Isidore Rigoutsos


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Y.K. and Z.M. conceived and designed the experiments; Y.K., N.K., M.P-S, E.K., S.C., P.S.K. and I.R. performed the experiments and analysis and generated all the figures; T.A.J. guided the Drosophila methodology and experiments; I.R. performed the bioinformatics analysis; T.A.J. and I.R. provided substantial input into the writing of the manuscript; Y.K. and Z.M. wrote the manuscript.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to Zissimos Mourelatos.

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