Effect of phenobarbitone on the nucleocytoplasmic transport of ribonucleic acid in vitro

Publisher Website
Google Scholar
Abstract
The effect of phenobarbitone on nucleocytoplasmic transport of ribosomes was measured in an assay system in vitro. The transport of radioactive ribosomes from isolated rat hepatic nuclei to unlabeled post-microsomal supernatant was measured in rats treated with 80 mg of phenobarbitone/kg body wt or saline 3 h before death. With either treatment, transport was linear with time, and dependent on temperature and the presence of ATP. Phenobarbitone treatment increased transport of ribonucleoproteins over saline-treated animals nearly 2-fold. The effect of phenobarbitone was mediated through the cytosol, but was not the result of altered stability of the RNA transported to the cytosol. Cycloheximide (5 mg/kg body wt) given 3.5 h before death inhibited the stimulation of transport by phenobarbitone. Phenobarbitone increased the transport of RNA by stimulating the synthesis of cytosol factors that regulate transport of RNA from the nucleus.