DIFFERENTIAL INHIBITION BY ACTINOMYCIN PUROMYCIN AND HYDROXYUREA OF PROTEIN SYNTHESIS IN NUCLEUS AND CYTOPLASM OF CHICK EMBRYO ERYTHROBLASTS

A highly reproducible technique combining measurements of specific radioactivity and amino acid analysis has clearly shown that actinomycin, puromycin and hydroxyurea exert differential effects upon the synthesis of nuclear histones as compared with other nuclear and cytoplasmic proteins in chick embryo erythroblasts: histone synthesis is less sensitive to puromycin, more sensitive to actinomycin and hydroxyurea than is the synthesis of other nuclear and cytoplasmic proteins. The differential effects observed may be significant of specific control mechanisms or synthetic pathways which are distinct for histones as compared with other proteins. Previous and present related studies suggest that a relationship exists between the primary and secondary effects of these inhibitors upon DNA (and perhaps RNA) synthesis and their action on histone synthesis. © 1969.