STIMULATION OF GLOBIN SYNTHESIS BY RNA PURIFIED FROM RETICULOCYTE SUPERNATANT FRACTION

Rabbit reticulocytes were preincubated in sodium fluoride to dissociate polyribosomes to 80S ribosomes, and RNA was phenol-extracted from the supernatant fraction of these cells after removing ribosomes. This purified RNA was fractionated by sucrose density gradient centrifugation, and found to contain a fraction corresponding to 6S to 14S which induced formation of polyribosomes active in protein synthesis and specifically stimulated rabbit α- and β-globin chain formation at least 2.5-fold in a cell-free system containing ribosomes prepared from fluoride-treated rabbit reticulocytes. No stimulation of protein synthesis was observed with addition of the RNA fraction to a cell-free system containing ribosomes prepared from reticulocytes not preincubated with sodium fluoride. Addition of this rabbit fluoride RNA to a mouse cell-free system stimulated amino acid incorporation into protein, but no formation of rabbit globin chains was detectable. © 1968.