THE 3' FLANKING REGION OF THE HUMAN ERYTHROPOIETIN-ENCODING GENE CONTAINS NITROGEN-REGULATORY OXYGEN-SENSING CONSENSUS SEQUENCES AND TISSUE-SPECIFIC TRANSCRIPTIONAL REGULATORY ELEMENTS

We have reported the identification of a classical canonical CAAT box, TATA boxes and other transcriptional regulatory elements in the 5' fl anking region of the human erythropoietin (hEp)-encoding gene (Lee-Hua ng et al., Gene 128 (1993) 227-236]. These elements were not found in the hEp genomic clones reported by others. Our genomic clone extends i n both directions beyond any reported clones, by 3.9 kb on the 5' side and by 1.8 kb on the 3' side. Many important regulatory elements are found in these extended flanking regions. We report here the genomic s tructure of the extended 3' flanking region of hEp. This region contai ns the following regulatory elements: nitrogen-regulatory/oxygen-sensi ng consensus sequences, 5'TTTTGCA and 5'-CCCTGCA; tissue-specific regu latory elements, including binding sites for A-activator, 5'-GTGGTGCAA ; for;DBP, 5'-TGATTTTGT; for HNF, 5'-T(A/G)TTTGT; and fbr C/EBP, 5'-T( T/G) (T/G)TGCAAT; a lymphokine-responsive element, 5'-GTGAAACCCC (Rev) , as well as binding sites for AP and Spl. In addition, the nucleotide (nt) sequence in this region is rich in inverted repeats (palindromes ) that allow the formation of hairpin loops. A total of 14 potential s tem loops with a maximum loop size of 20 nt are found. The identificat ion of these regulatory elements in hEp should provide further insight into the tissue-specific and inducible expression of hEp. Such knowle dge should be useful in the clinical modulation of erythropoiesis unde r physiologic and pathologic conditions.