Abstract: | When DNA synthesis is inhibited, the mRNAs coding for the replication-dependent histone proteins are selectively destabilized. The histone genes have been altered and reintroduced into tk- mouse L cells by cotransfection with the herpesvirus thymidine kinase gene. Two features of the mRNA are necessary for regulation of degradation: first, the hairpin loop must be present at the 3' end of the histone mRNA; and second, the histone mRNA must be capable of being translated to within 300 nucleotides of the 3' end of the RNA. Polyadenylated histone mRNAs are stable, as are histone mRNAs that contain in-frame termination codons early in the coding region or 500 nucleotide 3' untranslated regions with a normal hairpin loop at the 3' end. |