Breakdown of Rat-Liver Ergosomes in vivo after Actinomycin Inhibition of Messenger RNA Synthesis

Science  12 Apr 1963:
Vol. 140, Issue 3563, pp. 180-183
DOI: 10.1126/science.140.3563.180


Ribosomes isolated from rat liver occur predominantly in the form of aggregates (ergosomes) corresponding to multiples of 73S particles held together by messenger RNA. After injecting rats with actinomycin, these aggregates gradually break down in vivo to 73S monomers and 113S dimers. We conclude that the observed breakdown results from the degradation of messenger RNA and the prevention by actinomycin of the synthesis of new messenger RNA.