Unusual Sites of Arginine Methylation in Poly(A)-binding Protein II and in Vitro Methylation by Protein Arginine Methyltransferases PRMT1 and PRMT3*

Abstract

Arginine methylation is a post-translational modification found mostly in RNA-binding proteins. Poly(A)-binding protein II from calf thymus was shown by mass spectrometry and sequencing to containN G,N G-dimethylarginine at 13 positions in its amino acid sequence. Two additional arginine residues were partially methylated. Almost all of the modified residues were found in Arg-Xaa-Arg clusters in the C terminus of the protein. These motifs are distinct from Arg-Gly-Gly motifs that have been previously described as sites and specificity determinants for asymmetric arginine dimethylation. Poly(A)-binding protein II and deletion mutants expressed in Escherichia coli werein vitro substrates for two mammalian protein arginine methyltransferases, PRMT1 and PRMT3, withS-adenosyl-l-methionine as the methyl group donor. Both PRMT1 and PRMT3 specifically methylated arginines in the C-terminal domain corresponding to the naturally modified sites.

Footnotes

  • * This work was supported by the Training and Mobility of Researchers program of the European Union, the Deutsche Forschungsgemeinschaft, the Fonds der Chemischen Industrie (to E. W.), and National Institutes of Health Grants GM24797 and AI34567 (to H. H. and J. T.).The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

  • ** A postdoctoral trainee supported by USPHS Institutional National Research Service Award T32 CA09056.

  • §§ To whom correspondence should be addressed: Institut für Biochemie, Martin-Luther-Universität Halle-Wittenberg, Kurt-Mothes-Strasse 3, 06120 Halle, Germany. Tel.: 49-345-55-24920; Fax: 49-345-55-27014; E-mail: ewahle{at}biochemtech.uni-halle.de.

  • Abbreviations:
    RNP
    ribonucleoprotein
    DMA
    dimethylarginine
    GST
    glutathioneS-transferase
    MALDI-TOF-MS
    matrix-assisted laser desorption/ionization time-of-flight mass spectrometry
    MMA
    monomethylarginine
    PABP2
    poly(A)-binding protein II
    PRMT
    protein arginine methyltransferase
    HPLC
    high performance liquid chromatography
    • Received January 25, 1999.
    Table of Contents

    Submit your work to JBC.

    You'll be in good company.