Activation de la synthèse acellulaire de l'hémoglobine par l'acide ribonucléique

The rate of synthesis of hemoglobin in a cell-free system of rabbit reticulocytes is increased by the addition of RNA from rabbit liver, kidney and intestine. This stimulation involves neither transfer RNA, nor a release factor, nor a protection of endogenous RNA. The evidence that this stimulation really involves hemoglobin synthesis is based on the isolation of purified hemoglobin, on the comparison of the rate of incorporation of several labelled amino acids and also on the comparison of the effect of addition of RNA on the incorporation of these amino acids. The RNA's from guinea-pig, rat, mouse and chicken livers, are either inactive or inhibitory on the cell-free synthesis of rabbit hemoglobin. The problem of the existence of hemoglobin-specific messenger RNA in non-hematopoietic cells is discussed in relation with the cell differentiation of protein biosynthesis.