PRMT5 (Janus Kinase-binding Protein 1) Catalyzes the Formation of Symmetric Dimethylarginine Residues in Proteins

Abstract

We have identified a new mammalian protein arginine N-methyltransferase, PRMT5, formerly designated Janus kinase-binding protein 1, that can catalyze the formation of -N G -monomethylarginine and symmetric -N G ,N G -dimethylarginine in a variety of proteins. A hemagglutinin peptide-tagged PRMT5 complex purified from human HeLa cells catalyzes the S-adenosyl-L-[methyl-3 H]methionine-dependent in vitro methylation of myelin basic protein. When the radiolabeled myelin basic protein was acid-hydrolyzed to free amino acids, and the products were separated by high-resolution cation exchange chromatography, we were able to detect two tritiated species. One species co-migrated with a -N G -monomethylarginine standard, and the other cochromatographed with a symmetric -N G ,N G -dimethylarginine standard. Upon base treatment, this second species formed methylamine, a breakdown product characteristic of symmetric -N G ,N G -dimethylarginine. Further analysis of these two species by thin layer chromatography confirmed their identification as -N Gmonomethylarginine and symmetric -N G ,N G -dimethylarginine. The hemagglutinin-PRMT5 complex was also able to monomethylate and symmetrically dimethylate bovine histone H2A and a glutathione S-transferasefibrillarin (amino acids 1-148) fusion protein (glutathione S-transferase-GAR). A mutation introduced into the S-adenosyl-L-methionine-binding motif I of a myc-tagged PRMT5 construct in COS-1 cells led to a near complete loss of observed enzymatic activity. PRMT5 is the first example of a catalytic chain for a type II protein arginine N-methyltransferase that can result in the formation of symmetric dimethylarginine residues as observed previously in myelin basic protein, Sm small nuclear ribonucleoproteins, and other polypeptides.

Mammalian Protein Arginine Methyltransferase 7 (PRMT7) Specifically Targets RXR Sites in Lysine- and Arginine-rich Regions

“…Most PRMTs, including PRMT1, -3, -6, and -8, target glycine-and arginine-rich motifs, which are involved in mediating nucleic acid and protein interactions (39,40); CARM1/PRMT4 specifically methylates proline-, glycine-, and methionine-rich motifs (41), although PRMT5 works on both (41,42). Adding to this substrate profile, we now demonstrate that PRMT7 shows a unique substrate specificity that is distinct from other known PRMT members.…”

A Novel SET Domain Methyltransferase Modifies Ribosomal Protein Rpl23ab in Yeast

“…In vivo labeled cellular components from both the BY4742 parent strain and the ⌬ypl208w knock-out strain were thus fractionated using high salt A, amino acid analysis was performed as described previously (39). Gel slices corresponding to the 15-kDa methylated substrate were excised from SDS gels of purified large ribosomal subunit proteins from both the BY4742 and ⌬ypl208w strains.…”

“…The column was equilibrated and eluted with sodium citrate buffer (0.35 M NaOH, titrated to pH 5.27 with citric acid) at a flow rate of 1 ml/min at 55°C. Fractions were collected, and aliquots counted for radioactivity and assayed for amino acid content using a ninhydrin assay (39). B, radioactive fractions 39 -44 from the wild-type substrate amino acid analysis were pooled and desalted using a Sephadex G-15 column (1.5 cm in diameter and 77 cm in length), equilibrated with 0.1 M acetic acid.…”

Interplay between chromatin remodelers and protein arginine methyltransferases

“…Biochemical characterization revealed that PRMT5 is a type II methyltransferase that symmetrically methylates histones H3R8 and H4R3 along with other cellular proteins such as MBD2, SmD1, and SmD3 (Branscombe et al, 2001;Pal et al, 2003Pal et al, , 2004Ancelin et al, 2006;Guezennec et al, 2006;Tan and Nakielny, 2006). PRMT5 has been found in multiple complexes where it mediates diverse functions including RNA processing, transcriptional regulation, and muscle as well as germ line differentiation (Fabbrizio et al, 2002;Pal et al, 2003Pal et al, , 2004Ancelin et al, 2006;Guezennec et al, 2006;Dacwag et al, 2007).…”