Enzymic methylation of arginyl residues in -Gly-Arg-Gly- peptides

Young Lan Hyun, D. Betty Lew, Seung Hee Park, Chan Wha Kim, Woon Ki Paik, Sangduk Kim

Research output: Contribution to journalArticle

15 Citations (Scopus)

Abstract

N(G)-Methylation of arginine residues in many nucleic-acid-binding proteins are formed post-translationally, catalysed by S-adenosylmethionine: protein-arginine N-methyltransferase in their glycine-rich and arginine-rich motifs. The amino acid sequences of the stimulator of HIV-1 TAR (Tat-responsive element) RNA-binding protein (SRB) and fibronectin also show the presence of the internal -Gly-Arg-Gly- (-GRG-) sequence, which is potentially methylatable by the methyltransferase. To investigate the sequence requirement for methylation of these proteins, several synthetic oligopeptides with different chain lengths and sequences similar to the -GRG- regions of SRB and fibronectin were synthesized. Whereas the heptapeptide AGGRGKG (residues 16-22 in SRB) served as the methyl acceptor for the methyltransferase with a K(m) of 50 μM, the 19 mer peptide (residues 10-28 in SRB) was methylated with a K(m) of 8.3 μM, indicating that a greater peptide chain length yields a better methyl acceptor. Product analysis of the methylated [methyl-14C]SRB-peptide by HPLC indicated the formation of N(G)-monomethylarginine and N(G),N(G)-dimethyl(asymmetric)- arginine. Synthetic peptides containing the cell attachment sequence [Arg-Gly-Asp ('RGD')] in fibronectin, GRGDSPK, GGRGDSPK and GGGRGDSPK, were also studied; whereas GRGDSPK was a poor methyl acceptor, the longer peptides were better methyl accepters. To provide an understanding of the effect of methylation on fibronectin peptide, arginine-unmethylated and methylated GGRGDSPK were compared for their effect on the mitogenesis induced by β-hexosaminidase A and an agonistic antibody (mAb15) in bovine tracheal smooth-muscle cells; whereas the former inhibited 35-67% of mitogenesis at a concentration of 5-10 μM, the latter did not block mitogenesis. This lack of inhibition by the insertion of a methyl group on the arginyl residue of the cell attachment sequence might be due to the hindrance of the binding of fibronectin peptide to integrins.

Original languageEnglish
Pages (from-to)573-578
Number of pages6
JournalBiochemical Journal
Volume348
Issue number3
DOIs
Publication statusPublished - 2000 Jun 15

Keywords

  • Fibronectin-peptide
  • N(G)-methylarginine
  • Protein methylase I
  • RNA-binding protein
  • S-adenosylmethionine

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

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  • Cite this

    Hyun, Y. L., Lew, D. B., Park, S. H., Kim, C. W., Paik, W. K., & Kim, S. (2000). Enzymic methylation of arginyl residues in -Gly-Arg-Gly- peptides. Biochemical Journal, 348(3), 573-578. https://doi.org/10.1042/0264-6021:3480573