Peptides with sequences similar to glycine, arginine-rich motifs in proteins interacting with RNA are efficiently recognized by methyltransferase(s) modifying arginine in numerous proteins.

摘要: Several proteins that interact with RNA, e.g. the heterogenous ribonucleoprotein particle A and B proteins, fibrillarin nucleolin, contain modified amino acid NG,NG-dimethylarginine. Here, we report two synthetic peptides, Ac-GGRGGFGGRGGFGGRGGFG-NH2 (R3) GGFGGRGGFG-NH2 (R1), which are based on methylated sequences in inhibit methylation of a large majority methyl-accepting observed extracts adenosine dialdehyde-treated PC12 cells. Concomitantly, peptides themselves become methylated, suggesting they compete for same enzyme carries out bulk N-methylation R3 potently inhibits formation NG,NG-dimethylarginine substrates, lesser effect NG-monomethylarginine NG,N'G-dimethylarginine. Bovine brain contains an activity methylates methyl acceptors. After partial purification, bovine methyltransferase efficiently modifies R1, yielding half-maximal rates at approximately 0.2 2 microM peptide, respectively. search GenPept database FGGRGGF motif revealed 13 candidate acceptors containing arginine most similar substitutions or one mismatch. Of these, 10 known presumed to RNA. These findings consistent hypothesis