The "beta-like-globin" gene domain in human erythroid cells.

Abstract

We have mapped the distribution of the major and minor DNase I-hypersensitive sites in the human "fi-like-globin" gene domain. The minor DNase I-hypersensitive sites map close to the 5' end of each of the 13-like-globin genes. Their presence is specifically associated with the transcription of the immediate downstream fi-like-globin genes.The major DNase I-hypersensitive sites map in what appear to be the 5' and 3' boundary areas of the human fi-like-globin gene domain, a region estimated to span at least 90 kilobases of DNA. These major sites are present in various erythroid cells, which express predominantly either the embryonic, the fetal, or the adult (3-like-globin genes, and seem to be involved in derming the active j8-like-globin gene domain in cells of erythroid lineage. The four major DNase I-hypersensitive sites in the 5' boundary area, when correlated with sequencing data, are shown to be located in DNA regions containing enhancer core-like sequences and alternating purine and pyrimidine bases.The human "/3-like-globin" genes (hemoglobin P-chain gene cluster) encode, respectively, one embryonic (e), two fetal (G y and Ay), and two adult (8 and /3) globin chains. These genes have been shown to reside within "50 kilobases (kb) of chromosomal DNA in the transcriptional order 5' e-y.GAy. EXPERIMENTAL PROCEDURES Cells were grown as described (7). Human bone marrow cells were collected from cancer patients with normal marrow who were to undergo chemotherapy and bone marrow reinfusion. Isolated by dextran column chromatography, -25% of the nucleated cells were erythroid.DNase I-digestion, gel electrophoresis, RNA isolation, blotting, and hybridization were carried out as described (7). RESULTS Globin Gene Transcription in K562,HEL, Adult Human Marrow, and HL60 Cells. Nuclear and cytoplasmic RNAs were isolated from cells, and individual globin gene transcription was detected by "dot-blot" hybridization with e-,

Fetal hemoglobin in sickle cell anemia: genetic determinants of response to hydroxyurea

“…[10][11][12][13] The regulation of HbF level might be a complex genetic trait governed by genetic elements linked to the b-globin gene-like cluster and quantitative trait loci (QTL) present on chromosomes 6, 8 and on the X-chromosome; other regulatory loci are also likely to exist and epigenetic and cellular factors could also have regulatory roles. [14][15][16][17][18][19][20][21][22][23][24][25][26][27] It is possible that these and other regulatory elements also modulate the HbF response to HU. Accordingly, we hypothesized that single nucleotide polymorphisms (SNPs) in candidate genes or QTL with putative roles in the regulation of HbF production might modulate the HbF response to treatment with HU.…”

Human small Maf proteins form heterodimers with CNC family transcription factors and recognize the NF-E2 motif

“…The b-globin locus control region (LCR), which plays an essential role in this regulation (Grosveld et al, 1987), is divided into four distinct 200 ± 300 bp core regions (HS-1, HS-2, HS-3 and HS-4) all showing DNase I hypersensitivity (Grosveld et al, 1987;Tuan, 1985). Three types of DNA binding sites, i.e., GATA, Sp1 and NF-E2-like motifs, are found within the core sequences Talbot et al, 1990;Talbot and Grosveld, 1991).…”

Transcriptional activation by hypersensitive site three of the human β-globin locus control region in murine erythroleukemia cells

“…The LCR is characterized by the presence of four erythroid-specific, developmentally stable DNaseI hypersensitive sites [9]. We and others have previously shown that the activity of the LCR resides in these hypersensitive site (HS) regions and identified the core elements as 200-300 bp fragments [10][11][12][13][14].…”