The C. elegans PRMT-3 possesses a type III protein arginine methyltransferase activity

Abstract

Protein arginine methylation is a common post-translational modification in eukaryotes that is catalyzed by a family of the protein arginine methyltransferases (PRMTs). PRMTs are classified into three types: type I and type II add asymmetrically and symmetrically dimethyl groups to arginine, respectively, while type III adds solely monomethyl group to arginine. However, although the enzymatic activity of type I and type II PRMTs have been reported, the substrate specificity and the methylation activity of type III PRMTs still remains unknown. Here, we report the characterization of Caenorhabditis elegans PRMT-2 and PRMT-3, both of which are highly homologous to human PRMT7. We find that these two PRMTs can bind to S-adenosyl methionine (SAM), but only PRMT-3 has methyltransferase activity for histone H2A depending on its SAM-binding domain. Importantly, thin-layer chromatographic analysis demonstrates that PRMT-3 catalyzes the formation of monomethylated, but not dimethylated arginine. Our study thus identifies the first type III PRMT in C. elegans and provides a means to elucidate the physiological significance of arginine monomethylation in multicellular organisms.

Keywords::

• Arginine methylation
• monomethyl arginine
• mammalian PRMT7

Acknowledgements

We thank the Caenorhabditis Genetics Center for providing Bristol N2 wild-type. We also thank members of the Fukamizu laboratory for helpful discussions. This work was supported by Grants-in-Aid for Scientific Research on Priority Areas (17054004 to A.F.), and Grants-in-Aid for Young Scientists (20780237 and 22688029 to H.D.) from the Ministry of Education, Culture, Sports, Science, and Technology of Japan.

Declaration of interest

The authors declare no conflict of interest.