Identification and Characterization of a Conserved Erythroid-specific Enhancer Located in Intron 8 of the Human 5-Aminolevulinate Synthase 2 Gene

摘要: Abstract Thirty five kilobases of sequence encompassing the human erythroid 5-aminolevulinate synthase (ALAS2) gene have been determined. Analysis revealed a very low GC content, few repetitive elements, and evidence for insertion reverse-transcribed mRNA neighboring gene. We investigated whether introns 1, 3, 8, which correspond to DNase I-hypersensitivity sites in structurally related mouseALAS2 gene, affect expression humanALAS2 promoter transient assays. Whereas intron 3 was marginally inhibitory, 1 8 stimulated activity. Intron harbored strong erythroid-specific enhancer activity orientation-dependent. Deletion analysis this region localized fragment 239 base pairs. Transcription factor binding clustered within include GATA motifs CACCC boxes, critical regulatory sequences many cell-expressed genes. These were also identified corresponding both murine canine ALAS2genes. Mutagenesis these conserved cells established functional importance one motif two boxes. The bound GATA-1 vitro. boxes each Sp1 or protein vitro, but Kruppel-like basic could not be detected. activated by together with transactivation experiments COS-1 indicating involvement another unidentified factor. Overall, results demonstrate that GATA-1-binding site located ALAS2 are transfected cells, due nature across species, it seems likely play role tissue-restricted vivo.