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Updated: Mar 7, 2026
Quantitative Methods to Study Protein Arginine Methyltransferase 1-9 Activity in Cells
Published on: August 7, 2021
PRMT-5 converts monomethylarginines into symmetrical dimethylarginines in Caenorhabditis elegans
Akihiko Kanou1, Koichiro Kako2, Keiko Hirota2,3
1Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8577, Japan.
Abstract:
The transmethylation to arginine residues of proteins is catalyzed by protein arginine methyltransferases (PRMTs) that form monomethylarginine (MMA), asymmetric (ADMA) and symmetric dimethylarginines (SDMA). Although we previously demonstrated that the generation of ADMA residues in whole proteins is driven by PRMT-1 in Caenorhabditis elegans, much less is known about MMA and SDMA in vivo. In this study, we measured the amounts of different methylarginines in whole protein extracts made from wild-type (N2) C. elegans and from prmt-1 and prmt-5 null mutants using liquid chromatography-tandem mass spectrometry. Interestingly, we found that the amounts of MMA and SDMA are about fourfold higher than those of ADMA in N2 protein lysates using acid hydrolysis. We were unable to detect SDMA residues in the prmt-5 null mutant. In comparison with N2, an increase in SDMA and decrease in MMA were observed in prmt-1 mutant worms with no ADMA, but ADMA and MMA levels were unchanged in prmt-5 mutant worms. These results suggest that PRMT-1 contributes, at least in part, to MMA production, but that PRMT-5 catalyzes the symmetric dimethylation of substrates containing MMA residues in vivo.
Insights
Protein arginine methyltransferases (PRMTs) modify proteins. This study shows PRMT-1 produces monomethylarginine (MMA), while PRMT-5 catalyzes symmetric dimethylarginine (SDMA) formation in C. elegans.
Area of Science:
- Molecular biology
- Biochemistry
- Proteomics
Background:
- Protein arginine methyltransferases (PRMTs) catalyze the methylation of arginine residues, producing monomethylarginine (MMA), asymmetric (ADMA), and symmetric dimethylarginines (SDMA).
- While PRMT-1's role in ADMA generation is known, the in vivo functions of MMA and SDMA production remain less understood.
- Investigating the specific roles of PRMTs in methylarginine production is crucial for understanding cellular methylation processes.
Purpose of the Study:
- To quantify and compare the levels of different methylarginines (MMA, ADMA, SDMA) in wild-type and mutant Caenorhabditis elegans strains.
- To elucidate the specific roles of PRMT-1 and PRMT-5 in the in vivo production of these methylarginine marks.
Main Methods:
- Utilized liquid chromatography-tandem mass spectrometry (LC-MS/MS) to measure methylarginine levels.
- Analyzed whole protein extracts from wild-type (N2), prmt-1 null mutant, and prmt-5 null mutant C. elegans.
- Employed acid hydrolysis for sample preparation prior to mass spectrometry analysis.
Main Results:
- In wild-type C. elegans, MMA and SDMA levels were approximately fourfold higher than ADMA levels.
- SDMA residues were undetectable in prmt-5 null mutants.
- prmt-1 mutants showed increased SDMA and decreased MMA, with no detectable ADMA, while prmt-5 mutants had unchanged ADMA and MMA levels compared to wild-type.
Conclusions:
- PRMT-1 contributes to MMA production in C. elegans.
- PRMT-5 is essential for the in vivo formation of SDMA from MMA-containing substrates.
- These findings clarify the distinct roles of PRMT-1 and PRMT-5 in methylarginine metabolism.
