[Transfer of proteins synthesized in the cytoplasm into mitochondria. Stimulation of mitochondrial protein synthesis by microsomal fraction].

The in vitro transport into mitochondria of proteins synthesized in the cytoplasm was studied. The system, in which the microsomes synthesize protein in the presence of mitochondria directly during the experiment proved to be the most efficient one. The microsomal fraction significantly stimulated the incorporation of 14C-valine into the isolated mitochondria proteins. The effects of EDTA treatment of the mitochondrial fraction, the dependence of protein synthesis stimulation on the ratio of mitochondria and microsomal proteins and the kinetic pattern of the reaction suggest that the stimulation of the labelled precursor incorporation into mitochondrial proteins is not probably due to the labelled microsomes adsorption on the mitochondria.