Alterations of tRNA modification in mammalian systems: the effect of ethionine.
AUTOR(ES)
Friedman, S
RESUMO
The relationship between the modification of tRNA and its ability to act as a substrate for homologous tRNA modification enzymes in vitro was studied. The tRNA extracted from the livers of rats was active as a substrate for in vitro methylation with extracts from normal rat liver 19 h after treatment with L-ethionine (35 mg/100 g/24 h). After 4 weeks of feeding a diet containing o.25% DL-ethionine, the tRNA was a poor substrate for methylation in vitro, even though it was deficient in methylated nucleosides. Only 18% and 7% of the available sites could be methylated after 67 h and 4 weeks, respectively, of ethionine treatment. 3-(3-amino-3-carboxypropyl)uridine, a nucleoside that is also synthesized from S-adenosylmethionine, was assayed in individual tRNAs by their reactivity with the N-hydroxysuccinimide ester of phenoxyacetic acid. The reactivity of tRNAIle, tRNAAsn, and tRNAThr was decreased by treatment with ethionine at 67 h as well as at 2 and 4 weeks, although no difference could be detected at 19 h.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=342527Documentos Relacionados
- Selective inhibition of uracil tRNA methylases of E. coli by ethionine.
- Methyl-deficient mammalian transfer RNA: II. Homologous methylation in vitro of liver tRNA from normal and ethionine-fed rats: ethionine effect on 5-methylcytidine synthesis in vivo
- Methyldeficient mammalian 4S RNA: evidence for L-ethionine-induced inhibition of N6-dimethyladenosine synthesis in rat liver tRNA
- Effects of DL-ethionine on mouse liver tRNA base composition.
- Posttranscriptional modification of tRNA in psychrophilic bacteria.