Differences in human alpha-, beta- and delta-globin gene expression in monkey kidney cells.
We have compared the function of the human alpha-, beta- and delta-globin genes using various plasmid expression vectors derived from pBR322. Amplification of recombinants occurred after their introduction, by calcium-phosphate-mediated DNA transfer, into monkey kidney cells that constitutively produce T antigen (COS cells). The human alpha-globin gene promoter functioned independently, but the beta-globin gene promoter was nearly totally dependent on the enhancing activity of the 72 bp direct repeats from the SV40 genome. Furthermore, when the human alpha- and beta-globin genes were linked in the same vector, the alpha promoter was active but the beta promoter was not. Function of the delta-globin gene promoter also depended on the enhancer element. In vectors containing the 72 bp repeats and the beta- or delta-globin gene, the activity of the beta-globin gene was approximately 50 times greater than that of the delta-globin gene, approximating the ratio of beta and delta mRNA observed in normal human bone marrow cells.
D000818:Animals; D002460:Cell Line; D004261:DNA Replication; D004274:DNA, Recombinant; D005786:Gene Expression Regulation; D005814:Genes, Viral; D005822:Genetic Vectors; D005914:Globins / Q000235:genetics*; D000882:Haplorhini; D006801:Humans; D009876:Operon; D012333:RNA, Messenger / Q000235:genetics; D012091:Repetitive Sequences, Nucleic Acid; D013539:Simian virus 40 / Q000235:genetics; D014158:Transcription, Genetic
D004274:DNA, Recombinant; D012333:RNA, Messenger; D005914:Globins