Accumulation and turnover of free and membrane-bound ribosomes in rat liver during short-term protein malnutrition
1979
Lewis, Charles G. | Winick, Myron
Liver cytoplasmic rRNA was studied in rats fed a 6 percent casein diet for 1 week. In protein restricted rats the release of mature rRNA from the nucleolus was slower than in controls, but rRNA was transported to the cytoplasm at a rate similar to controls. Accumulation of newly synthesized rRNA in malnourished rat liver cytoplasm was 40 percent lower than in controls. Specific activity of free and membrane bound rRNA was 1.5 times greater in malnourished rat cytoplasm. The half-life, turnover, and fractional turnover values are reported. Results suggest that nuclear mechanisms are responsible for the decrease in cytoplasm rRNA content during dietary protein restriction.
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