Correlation between patterns of DNase I-hypersensitive sites and upstream promoter activity of the human epsilon-globin gene at different stages of erythroid development

1990 ◽  
Vol 10 (3) ◽  
pp. 1199-1208
Author(s):  
P Bushel ◽  
K Rego ◽  
L Mendelsohn ◽  
M Allan

DNA 5' to the human epsilon-globin gene exhibits unique patterns of DNase I-hypersensitive sites (DHS) in three human erythroleukemic cell lines which represent the embryonic (K562), fetal (HEL), and adult (KMOE) stages of erythroid development. We have mapped 10 epsilon-globin DHS in K562 cells, in which the epsilon-globin gene is maximally active. Major sites are located -11.7, -10.5, -6.5, -2.2 kilobase pairs (kbp) and -200 base pairs (bp) upstream of the gene and directly over the major cap site. Minor sites are located -5.5, -4.5, and -1.48 kbp and -900 bp upstream of the cap site. In HEL cells, in which the epsilon-globin gene is expressed at extremely low levels, the -11.7-, -10.5-, -5.5-, -4.5-, and -2.2-kbp DHS are no longer detectable; the -200-bp site is approximately 300-fold less sensitive to DNase I; and the -1.48-kbp, -900-bp, and major cap site DHS are 3- to 4-fold less sensitive. Only the DHS located -6.5 kbp relative to the major cap site is detectable at all three stages of erythroid development, including KMOE cells in which epsilon-globin synthesis is undetectable. We suggest that this site may be implicated in maintaining the entire beta-globin cluster in an active chromatin conformation. The five DHS downstream of the -6.5-kbp element possess associated promoters. Thus two distinct types of DHS exist--promoter positive and promoter negative. In HEL cells, all the upstream promoters are inactivated, although the -1.48-kbp and -900- and -200-bp DHS are still present. This suggests that the maintenance of DHS and regulation of their associated promoters occur by independent mechanisms. The inactivation of the upstream promoters in HEL cells while the major cap site remains active represents a unique pattern of expression and suggests that HEL cells possess regulatory factors which specifically down regulate the epsilon-globin upstream promoters.

1990 ◽  
Vol 10 (3) ◽  
pp. 1199-1208 ◽  
Author(s):  
P Bushel ◽  
K Rego ◽  
L Mendelsohn ◽  
M Allan

DNA 5' to the human epsilon-globin gene exhibits unique patterns of DNase I-hypersensitive sites (DHS) in three human erythroleukemic cell lines which represent the embryonic (K562), fetal (HEL), and adult (KMOE) stages of erythroid development. We have mapped 10 epsilon-globin DHS in K562 cells, in which the epsilon-globin gene is maximally active. Major sites are located -11.7, -10.5, -6.5, -2.2 kilobase pairs (kbp) and -200 base pairs (bp) upstream of the gene and directly over the major cap site. Minor sites are located -5.5, -4.5, and -1.48 kbp and -900 bp upstream of the cap site. In HEL cells, in which the epsilon-globin gene is expressed at extremely low levels, the -11.7-, -10.5-, -5.5-, -4.5-, and -2.2-kbp DHS are no longer detectable; the -200-bp site is approximately 300-fold less sensitive to DNase I; and the -1.48-kbp, -900-bp, and major cap site DHS are 3- to 4-fold less sensitive. Only the DHS located -6.5 kbp relative to the major cap site is detectable at all three stages of erythroid development, including KMOE cells in which epsilon-globin synthesis is undetectable. We suggest that this site may be implicated in maintaining the entire beta-globin cluster in an active chromatin conformation. The five DHS downstream of the -6.5-kbp element possess associated promoters. Thus two distinct types of DHS exist--promoter positive and promoter negative. In HEL cells, all the upstream promoters are inactivated, although the -1.48-kbp and -900- and -200-bp DHS are still present. This suggests that the maintenance of DHS and regulation of their associated promoters occur by independent mechanisms. The inactivation of the upstream promoters in HEL cells while the major cap site remains active represents a unique pattern of expression and suggests that HEL cells possess regulatory factors which specifically down regulate the epsilon-globin upstream promoters.


2021 ◽  
Author(s):  
Yujin Kang ◽  
Jin Kang ◽  
AeRi Kim

Super-enhancers, which consist of multiple enhancer elements, are occupied by master transcription factors and coactivators, such as Mediator, and are highly acetylated at histone H3K27. Here, we have characterized the super-enhancers in terms of DNase I hypersensitive sites (DHSs) by analyzing publicly available ChIP-seq and DNase-seq data of K562 cells and compared to the DHSs in typical enhancers. DHSs in the super-enhancers were highly marked by histone H3K4me1 than DHSs in typical enhancers. Loss of H3K4me1 by the deletion of catalytic domains in histone methyltransferases MLL3 and MLL4 remarkably decreased histone H3K27ac and histone H3 depletion at super-enhancer DHSs than at typical enhancer DHSs. The levels of enhancer RNA (eRNA) transcripts and mRNA transcripts from the putative target genes were notably reduced at and near super-enhancer DHSs than typical enhancer DHSs following H3K4me1 loss. These results indicate that histone H3K4me1 is a marker for DHSs in super-enhancers and that this modification has a more significant impact on the activation of super-enhancer DHSs than typical enhancer DHSs.


2005 ◽  
Vol 25 (16) ◽  
pp. 7033-7041 ◽  
Author(s):  
Xiangdong Fang ◽  
Jin Sun ◽  
Ping Xiang ◽  
Man Yu ◽  
Patrick A. Navas ◽  
...  

ABSTRACT Deletion of the 234-bp core element of the DNase I hypersensitive site 3 (5′HS3) of the locus control region (LCR) in the context of a human beta-globin locus yeast artificial chromosome (β-YAC) results in profound effects on globin gene expression in transgenic mice. In contrast, deletion of a 2.3-kb 5′HS3 region, which includes the 234-bp core sequence, has a much milder phenotype. Here we report the effects of these deletions on chromatin structure in the beta-globin locus of adult erythroblasts. The 234-bp 5′HS3 deletion abolished histone acetylation throughout the β-globin locus; recruitment of RNA polymerase II (pol II) to the LCR and beta-globin gene promoter was reduced to a basal level; and formation of all the 5′ DNase I hypersensitive sites of the LCR was disrupted. The 2.3-kb 5′HS3 deletion mildly reduced the level of histone acetylation but did not change the profile across the whole locus; the 5′ DNase I hypersensitive sites of the LCR were formed, but to a lesser extent; and recruitment of pol II was reduced, but only marginally. These data support the hypothesis that the LCR forms a specific chromatin structure and acts as a single entity. Based on these results we elaborate on a model of LCR chromatin architecture which accommodates the distinct phenotypes of the 5′HS3 and HS3 core deletions.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 1219-1219
Author(s):  
Ping Xiang ◽  
Hemei Han ◽  
Xiangdong Fang ◽  
George Stamatoyannopoulos ◽  
Qiliang Li

Abstract Formation of DNase I hypersensitive sites is an indication of local disruption of chromatin conformation. It has been documented that HS sites are frequently associated with functional DNA sequences, such as, promoters, enhancers, and insulators. While Southern blot hybridization is the standard method to detect HS sites, this procedure is time-consuming and labor intensive. To improve the efficiency of HS detection through Southern blot hybridization, we designed a contigs strategy of Southern blot hybridization and test it in the 200 kb region 5′ to the LCR in the b-globin locus. Based on the human genome sequence we made physical maps of seven 6-bp-cut restriction enzymes in the 200 kb region. From the map we selected continuous contigs of 10 to 15 kb fragment; and designed hybridization probes for the 5′ and 3′ ends of each fragment (some probes can be used in two neighboring fragments). The screening was performed on erythroid (K562) and non-erythroid (Jurkat) cell lines. We found about 40 HS sites within the region. The major sites were either erythroid specific (for instance, HSs at −66 kb, −142 kb, and −236 kb, the cap site of the e-globin gene is +1), or non-erythroid specific (for instances, HSs at −111 kb, −164 kb, and −205 kb). These HS sites will be investigated for enhancer, promoter, and insulator function using transient and stable transfection studies. Due to the limited number of enzyme required and the fact that each blot could be used several times, this strategy can greatly expedite the screening process for presence of DNase I hypersensitive sites. Estimated efficiency of this screening approach is about 0.5 to1 Mb per person per year.


1984 ◽  
Vol 4 (9) ◽  
pp. 1853-1863 ◽  
Author(s):  
N Costlow ◽  
J T Lis

High-resolution analysis of the chromatin structure of the promoter regions of five Drosophila heat shock genes showed a similar location for the hypersensitive sequences relative to the start of transcription. For each of the five genes examined--those coding for hsp27, hsp26, hsp23, hsp70, and hsp83--the DNase I-hypersensitive sites in Drosophila melanogaster nuclei mapped to two regions upstream of the coding region. These sites occurred on the average, 115 and 17 base pairs upstream from the start of transcription of the five heat shock genes examined. This latter site corresponded to sequences at or near the TATA consensus sequence. Sites even further upstream of the hsp27, hsp26, and hsp83 genes were also evident. Additionally, for the two genes examined--hsp70 and hsp83--the DNase I-hypersensitive sites were preserved, at least within this level of resolution (+/- 10 base pairs), when the Drosophila genes were integrated into the Saccharomyces cerevisiae genome. This result indicates that the signals responsible for generating these hypersensitive sites are inherent in the DNA sequences and, in this case, are not highly species specific.


1984 ◽  
Vol 4 (9) ◽  
pp. 1853-1863
Author(s):  
N Costlow ◽  
J T Lis

High-resolution analysis of the chromatin structure of the promoter regions of five Drosophila heat shock genes showed a similar location for the hypersensitive sequences relative to the start of transcription. For each of the five genes examined--those coding for hsp27, hsp26, hsp23, hsp70, and hsp83--the DNase I-hypersensitive sites in Drosophila melanogaster nuclei mapped to two regions upstream of the coding region. These sites occurred on the average, 115 and 17 base pairs upstream from the start of transcription of the five heat shock genes examined. This latter site corresponded to sequences at or near the TATA consensus sequence. Sites even further upstream of the hsp27, hsp26, and hsp83 genes were also evident. Additionally, for the two genes examined--hsp70 and hsp83--the DNase I-hypersensitive sites were preserved, at least within this level of resolution (+/- 10 base pairs), when the Drosophila genes were integrated into the Saccharomyces cerevisiae genome. This result indicates that the signals responsible for generating these hypersensitive sites are inherent in the DNA sequences and, in this case, are not highly species specific.


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