Effect of plumbous ion on messenger RNA.
The effects of Pb2+, a potent catalyst for the depolymerization of RNA have been studied on brome mosaic virus (BMV) RNA, rabbit globin m-RNA and polyuridylic acid. After exposure of these natural and synthetic messengers to a sufficiently high concentration of Pb2+, they all lost their ability to stimulate amino acid incorporation in cell-free protein-synthesizing systems. There were differences in the susceptibilities of the messengers; gloing the m-RNA for 40 min revealed that there was a threshold Pb2+ concentration below which no loss of m-RNA activity was observed. The threshold concentration was considerably greater than the Pb2+ concentration at which protein synthesis is inhibited in reticulocytes and overt symptoms of plumbism are observed. However, when m-RNA were incubated for an extended period (24 h), even with sub-threshold concentrations of Pb2+, there was destruction of messenger function and globin m-RNA was more susceptible than BMV-RNA. Also the susceptibility of m-RNA to Pb2+ is temperature-dependent, which would indicate that m-RNA, like t-RNA, exists as a population of molecules in different conformational states that are not readily interconvertible.
D000818:Animals; D005914:Globins / Q000096:biosynthesis; D007700:Kinetics; D007854:Lead / Q000494:pharmacology*; D010452:Peptide Biosynthesis; D010649:Phenylalanine / Q000378:metabolism; D010942:Plant Viruses / Q000378:metabolism; D010944:Plants / Q000378:metabolism; D011072:Poly U / Q000494:pharmacology; D014176:Protein Biosynthesis / Q000187:drug effects*; D012333:RNA, Messenger / Q000378:metabolism*; D012343:RNA, Transfer / Q000378:metabolism; D051381:Rats; D014908:Triticum / Q000378:metabolism
D012333:RNA, Messenger; D011072:Poly U; D007854:Lead; D010649:Phenylalanine; D005914:Globins; D012343:RNA, Transfer