Characterization of RNA Associated with Rat Liver Plasma Membranes

Abstract

RNA was extracted from purified rat liver plasma membranes. The RNA was characterized in terms of molecular weight distribution (electrophoresis) and base composition. Plasma membrane RNA was shown to have a major 28S species, several minor 15-22S species and another minor 4S species. There was no difference between plasma membrane RNA and ribosomal RNA in terms of base composition. The intact plasma membrane was incubated in the presence of RNAse as well as varying concentrations of NaCl. These results demonstrate that the RNA associated with the plasma membrane is partially digested with RNAse, while 0.15 M NaCl seems to have little effect on the plasma membrane RNA content. This may indicate that the plasma membrane RNA is protruding from the plasma membrane but is attached to the plasma membrane in some manner. Incubation of intact plasma membranes with 0.30 M NaCl (final concentration) removes 63.2% of the RNA associated with the plasma membrane. The species of RNA released is unknown.