Yeast Ribosomal Protein L12 Is a Substrate of Protein-arginine Methyltransferase 2

Ming-Kai Chern, Kwang-Ning Chang, Li-Fan Liu, Tsuey-Chyi S. Tam, Yi-Chen Liu, Yi-Lin Liang, Ming F. Tam
2002 Journal of Biological Chemistry  
Type III protein-arginine methyltransferase from the yeast Saccharomyces cerevisiae (RMT2) was expressed in Escherichia coli and purified to apparent homogeneity. The cytosolic, ribosomal, and ribosome salt wash fractions from yeast cells lacking RMT2 were used as substrates for the recombinant RMT2. Using S-adenosyl-L-methionine as co-substrate, RMT2 methylated a protein in the ribosome salt wash fraction. The same protein in the ribosomal fraction was also methylated by RMT2 after pretreating
more » ... the sample with endonuclease. Amino acid analysis affirmed that the labeling products were ␦-N-monomethylarginines. The methylated protein from the ribosomal or the ribosome salt wash fraction was isolated by two-dimensional gel electrophoresis and identified as ribosomal protein L12 by mass spectrometry. Using synthetic peptides, recombinant L12, and its mutant as substrates, we pinpointed Arg 67 on ribosomal protein L12 as the methyl acceptor. L12 was isolated from wild type yeast cells that have been grown in the presence of S-adenosyl-L-[methyl-3 H]methionine and subjected to amino acid analysis. The results indicate that L12 contains ␦-N-monomethylarginines. Proteins can have a large variety of post-translational modifications, including the N-methylation of the arginine side chains. The process involves the transfer of methyl group from S-adenosyl-L-methionine (AdoMet) 1 to the guanidino nitrogen atoms of arginine with protein-arginine N-methyltransferases
doi:10.1074/jbc.m111379200 pmid:11856739 fatcat:lp2rw4bpzjcghhbngbldjea4ea