Recent advances in protein methylation: enzymatic methylation of nucleic acid binding proteins.
Heterogeneous nuclear RNP protein A1, one of the major proteins in hnRNP particle (precursor for mRNA), is known to be posttranslationally arginine-methylated in vivo on residues 193, 205, 217 and 224 within the RGG box, the motif postulated to be an RNA binding domain. Possible effect of NG-arginine methyl-modification in the interaction of protein A1 to nucleic acid was investigated. The recombinant hnRNP protein A1 was in vitro methylated by the purified nuclear protein/histone-specific protein methylase I (S-adenosylmethionine:protein-arginine N-methyltransferase) stoichiometrically and the relative binding affinity of the methylated and the unmethylated protein A1 to nucleic acid was compared: Differences in their binding properties to ssDNA-cellulose, pI values and trypsin sensitivities in the presence and absence of MS2-RNA all indicate that the binding property of hnRNP protein A1 to single-stranded nucleic acid has been significantly reduced subsequent to the methylation. These results suggest that posttranslational methyl group insertion to the arginine residue reduces protein-RNA interaction, perhaps due to interference of H-bonding between guanidino nitrogen arginine and phosphate RNA.
Kim
S
S
Department of Biochemistry, Medical School, Korea University, Seoul, Korea.
Park
G H
GH
Paik
W K
WK
D000595:Amino Acid Sequence; D000818:Animals; D001921:Brain / Q000201:enzymology; D002417:Cattle; D000076245:Heterogeneous Nuclear Ribonucleoprotein A1; D034481:Heterogeneous-Nuclear Ribonucleoprotein Group A-B; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D008099:Liver / Q000201:enzymology; D008745:Methylation; D008956:Models, Chemical; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000737:chemistry; D011499:Protein Processing, Post-Translational; D011484:Protein-Arginine N-Methyltransferases / Q000737:chemistry; D051381:Rats; D012261:Ribonucleoproteins / Q000737:chemistry* / Q000378:metabolism*; D013997:Time Factors
D000076245:Heterogeneous Nuclear Ribonucleoprotein A1; D034481:Heterogeneous-Nuclear Ribonucleoprotein Group A-B; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D009687:Nuclear Proteins; D012261:Ribonucleoproteins; D011484:Protein-Arginine N-Methyltransferases