Alterations in Gene Expression Due to Methylmercury in Central and Peripheral Nervous Tissues of the Rat
Polyadenylated messenger RNAs (poly (A) + mRNA) obtained from the brain of control and methylmercury (MeHg) -treated rats were translated in reticulocyte lysate system in the presence of 35S-methionine or 3H-leucine. The 3H-labelled translation products of the control poly (A)+ mRNA were added to each of the 35S-labelled translation products as an internal standard, and the mixture was analyzed by two-dimensional electrophoresis. The results showed that the effect of MeHg on the synthesis of proteins in the brain was not uniform for individual protein species in the early, latent and symptomatic periods of MeHg intoxication. Among 120 protein species examined, the numbers of protein species the synthetic activities of which were significantly reduced/increased were 25/34 on the early period, 5/67 on the latent period and 4/99 on the symptomatic period.
These results suggest that MeHg affect differently the synthesis of brain proteins and the unusual reduction or elevation of certain protein species caused by perturbation of the synthetic rates by MeHg may be responsible for the impairment of normal nerve functions.
KeywordsProtein Spot Synthetic Activity Protein Species Synthetic Rate Template Activity
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