1. PRMT1 is the predominant type I protein arginine methyltransferase in mammalian cells.
- Author
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Tang J, Frankel A, Cook RJ, Kim S, Paik WK, Williams KR, Clarke S, and Herschman HR
- Subjects
- Animals, Methylation, Mice, Mice, Mutant Strains, Oxidoreductases Acting on CH-NH Group Donors genetics, Oxidoreductases Acting on CH-NH Group Donors isolation & purification, Protein Methyltransferases classification, Protein Methyltransferases isolation & purification, Protein Processing, Post-Translational, Protein-Arginine N-Methyltransferases classification, Protein-Arginine N-Methyltransferases isolation & purification, Rats, S-Adenosylmethionine metabolism, Arginine metabolism, Oxidoreductases Acting on CH-NH Group Donors metabolism, Protein Methyltransferases metabolism, Protein-Arginine N-Methyltransferases metabolism
- Abstract
Type I protein arginine methyltransferases catalyze the formation of asymmetric omega-N(G),N(G)-dimethylarginine residues by transferring methyl groups from S-adenosyl-L-methionine to guanidino groups of arginine residues in a variety of eucaryotic proteins. The predominant type I enzyme activity is found in mammalian cells as a high molecular weight complex (300-400 kDa). In a previous study, this protein arginine methyltransferase activity was identified as an additional activity of 10-formyltetrahydrofolate dehydrogenase (FDH) protein. However, immunodepletion of FDH activity in RAT1 cells and in murine tissue extracts with antibody to FDH does not diminish type I methyltransferase activity toward the methyl-accepting substrates glutathione S-transferase fibrillarin glycine arginine domain fusion protein or heterogeneous nuclear ribonucleoprotein A1. Similarly, immunodepletion with anti-FDH antibody does not remove the endogenous methylating activity for hypomethylated proteins present in extracts from adenosine dialdehyde-treated RAT1 cells. In contrast, anti-PRMT1 antibody can remove PRMT1 activity from RAT1 extracts, murine tissue extracts, and purified rat liver FDH preparations. Tissue extracts from FDH(+/+), FDH(+/-), and FDH(-/-) mice have similar protein arginine methyltransferase activities but high, intermediate, and undetectable FDH activities, respectively. Recombinant glutathione S-transferase-PRMT1, but not purified FDH, can be cross-linked to the methyl-donor substrate S-adenosyl-L-methionine. We conclude that PRMT1 contributes the major type I protein arginine methyltransferase enzyme activity present in mammalian cells and tissues.
- Published
- 2000
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