Polyadenylic acid-containing RNA from rat brain synaptosomes.

Abstract

Abstract— Synaptosomal RNA of rat brain was labelled in vivo by intracranial injection of tritiated uridine. The change in the specific activity of this material with time was similar to that of polysomal RNA. The percent of the radioactive synaptosomal RNA which bound to oligo(dT)‐cellulose columns decreased with time after intracranial labelling. The percent of the total synaptosomal RNA which bound to oligo(dT)‐cellulose was greater than that of polysomes. The length of the polyadenylate (poly(A)) sequence of synaptosomal RNA was approximately one‐half that of polysomal RNA, and about the same as that from mitochondria. Investigation of synaptosomal RNA using sucrose gradients and polyacrylamide gel electrophoresis indicated that there were several distinct species present, and that they were similar to those from the mitochondria. The poly(A)‐containing RNA isolated from synaptosomes stimulated the incorporation of radioactive leucine into TCA‐precipitable material in a cell‐free protein synthesis system. Isolation of RNA from subsynaptosomal components indicated that most, if not all, of the synaptosomal messenger activity was localized in the synaptic mitochondria.