Globin RNA transcription: a possible termination site and demonstration of transcriptional control correlated with altered chromatin structure.

The transcription unit that encodes beta-globin (major) mRNA has been examined by analysis of nascent labeled RNA from the nuclei of mouse erythroleukemia cells treated with agents that induce beta-globin formation. More than 95% of the time, transcription appears to terminate within a region 1400 +/- 100 nucleotides downstream from the poly(A) site. The nuclei of mouse erythroleukemia cells treated with agents that induce beta-globin synthesis showed a 10 to 20 fold stimulation of transcription assayed by chain elongation of beta-globin RNA sequences, including sequences downstream from the poly(A) site. Associated with the increase in transcription was a generalized increase in sensitivity to DNAase treatment of globin genomic DNA in whole nuclei. A DNAase I-hypersensitive site in the vicinity of the cap site was also found to be prominent in induced cells.