Human globin gene promoter sequences are sufficient for specific expression of a hybrid gene transfected into tissue culture cells

1987 ◽  
Vol 7 (1) ◽  
pp. 398-402
Author(s):  
T Rutherford ◽  
A W Nienhuis

The contribution of the human globin gene promoters to tissue-specific transcription was studied by using globin promoters to transcribe the neo (G418 resistance) gene. After transfection into different cell types, neo gene expression was assayed by scoring colony formation in the presence of G418. In K562 human erythroleukemia cells, which express fetal and embryonic globin genes but not the adult beta-globin gene, the neo gene was expressed strongly from a fetal gamma- or embryonic zeta-globin gene promoter but only weakly from the beta promoter. In murine erythroleukemia cells which express the endogenous mouse beta genes, the neo gene was strongly expressed from both beta and gamma promoters. In two nonerythroid cell lines, human HeLa cells and mouse 3T3 fibroblasts, the globin gene promoters did not allow neo gene expression. Globin-neo genes were integrated in the erythroleukemia cell genomes mostly as a single copy per cell and were transcribed from the appropriate globin gene cap site. We conclude that globin gene promoter sequences extending from -373 to +48 base pairs (bp) (relative to the cap site) for the beta gene, -385 to +34 bp for the gamma gene, and -555 to +38 bp for the zeta gene are sufficient for tissue-specific and perhaps developmentally specific transcription.

1987 ◽  
Vol 7 (1) ◽  
pp. 398-402 ◽  
Author(s):  
T Rutherford ◽  
A W Nienhuis

The contribution of the human globin gene promoters to tissue-specific transcription was studied by using globin promoters to transcribe the neo (G418 resistance) gene. After transfection into different cell types, neo gene expression was assayed by scoring colony formation in the presence of G418. In K562 human erythroleukemia cells, which express fetal and embryonic globin genes but not the adult beta-globin gene, the neo gene was expressed strongly from a fetal gamma- or embryonic zeta-globin gene promoter but only weakly from the beta promoter. In murine erythroleukemia cells which express the endogenous mouse beta genes, the neo gene was strongly expressed from both beta and gamma promoters. In two nonerythroid cell lines, human HeLa cells and mouse 3T3 fibroblasts, the globin gene promoters did not allow neo gene expression. Globin-neo genes were integrated in the erythroleukemia cell genomes mostly as a single copy per cell and were transcribed from the appropriate globin gene cap site. We conclude that globin gene promoter sequences extending from -373 to +48 base pairs (bp) (relative to the cap site) for the beta gene, -385 to +34 bp for the gamma gene, and -555 to +38 bp for the zeta gene are sufficient for tissue-specific and perhaps developmentally specific transcription.


2002 ◽  
Vol 282 (1) ◽  
pp. R173-R183 ◽  
Author(s):  
Min Nian ◽  
Jun Gu ◽  
David M. Irwin ◽  
Daniel J. Drucker

The glucagon-like peptides (GLPs) are synthesized and secreted in a nutrient-dependent manner in rodents; however, the factors regulating human GLP-1 and GLP-2 biosynthesis remain unclear. To understand how nutrients regulate human proglucagon gene expression, we studied the expression of a human proglucagon promoter-growth hormone (GH) transgene in 1.6 human glucagon-GH transgenic mice. Fasting-refeeding significantly decreased and increased the levels of circulating mouse insulin and transgene-derived hGH ( P < 0.05 fasting vs. refeeding) and decreased and upregulated, respectively, the levels of endogenous mouse proglucagon RNA in the ileum but not in the jejunum or colon. High-fiber feeding significantly increased the levels of glucose-stimulated circulating hGH and upregulated levels of mouse intestinal proglucagon gene expression in the jejunum, ileum, and colon ( P < 0.05, 0 vs. 30% fiber diet). In contrast, neither fasting-refeeding nor a high-fiber diet upregulated the expression of the human proglucagon promoter-hGH transgene. These findings demonstrate that human proglucagon gene regulatory sequences specifying tissue-specific expression in gut endocrine cells are not sufficient for recognition of energy-derived signals regulating murine glucagon gene expression in enteroendocrine cells in vivo.


Blood ◽  
1985 ◽  
Vol 65 (3) ◽  
pp. 705-712 ◽  
Author(s):  
NP Anagnou ◽  
TY Yuan ◽  
E Lim ◽  
J Helder ◽  
S Wieder ◽  
...  

Abstract In order to test if trans-acting regulatory factors specific for globin genes of the adult and embryonic stages of development exist in erythroid cells, transcriptionally active embryonic and adult globin genes on the same chromosome were transferred by cell fusion from the human leukemia cell K562 into phenotypically adult mouse erythroleukemia cells. Restriction-fragment-length polymorphisms of the K562 zeta (embryonic) globin genes were used to establish that all three copies of human chromosome 16 present in the K562 cell showed the same pattern of human globin gene expression after transfer to the mouse erythroleukemia cell. Adult (alpha) but not embryonic (zeta) human globin mRNA was detected in all nine of the independently derived mouse erythroleukemia hybrid cells, each of which contained human chromosome 16. Restriction endonuclease studies of the K562 alpha- and zeta-globin genes after transfer into the mouse erythroleukemia cell showed no evidence of rearrangements or deletions that could explain this loss of zeta-globin gene expression. These data suggest that regulation of globin gene expression in these erythroleukemia cells involves trans-acting regulatory factors specific for the adult and embryonic stages of development.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 365-365 ◽  
Author(s):  
Valerie M. Jansen ◽  
Shaji Ramachandran ◽  
Aurelie Desgardin ◽  
Jin He ◽  
Vishwas Parekh ◽  
...  

Abstract Binding of EKLF to the proximal promoter CACC motif is essential for high-level tissue-specific β-globin gene expression. More recent studies have demonstrated that EKLF regulates expression of other erythroid-specific genes, suggesting a broad role for EKLF in co-ordinating gene transcription in differentiating erythroblasts. Given these observations, we hypothesized that EKLF may play a role in synchronizing α- and β-globin gene expression. Supporting this model, studies of fetal erythroblasts derived from EKLF-null embryos revealed a 3-fold reduction in murine α-globin gene expression in fetal erythroblasts when compared to wild type littermate controls. A similar reduction in primary α-globin RNA transcripts was observed in these studies. To further examine the molecular consequences of EKLF function at the α- and β-globin genes in vivo, we utilized an erythroid cell line derived from EKLF null fetal liver cells. We have demonstrated previously that introduction into these cells of the wildtype EKLF cDNA, fused in frame with a mutant estrogen response element results in tamoxifen-dependent rescue of β-globin gene expression. Consistent with our observations in primary erythroblasts, α-globin gene expression is present in the absence of functional EKLF. However, with tamoxifen induction, we observed a 3–5 fold increase in α-globin gene transcription. Interestingly, the kinetics of the changes in transcription of the α- and β-gene transcripts were similar. Enhancement in α-gene transcription was associated with EKLF binding at the α- and β-globin promoters as determined by a quantitative chromatin immunoprecipitation (ChIP) assay. Interestingly, maximal EKLF binding and α-gene transcription was observed within 2 hours of tamoxifen induction. We hypothesized that the role of EKLF may differ function at the promoters, given that a basal level of α-globin gene expression occurs in absence of EKLF binding. Supporting this hypothesis, we observed sequential recruitment of p45NF-E2, RNA polymerase II (Pol II) and the co-activator CBP to the β-promoter with tamoxifen induction. No change in GATA-1 binding was observed. In contrast, p45NF-E2 does not bind to the α-promoter and the kinetics of GATA-1 and PolII association is unchanged after tamoxifen induction. Taken together, our results demonstrate that EKLF regulates the co-ordinate high-level transcription of the α- and β-globin genes, binding in a kinetically identical manner to the gene promoters. However, the effects of EKLF on transacting factor recruitment (and chromatin modification) differ between the promoters, consistent with the idea that EKLF acts in a context-specific manner to modulate gene transcription.


Blood ◽  
1998 ◽  
Vol 92 (9) ◽  
pp. 3416-3421 ◽  
Author(s):  
E. Skarpidi ◽  
G. Vassilopoulos ◽  
G. Stamatoyannopoulos ◽  
Q. Li

To examine whether transfer of γ globin genes into mouse erythroleukemia cells can be used for the analysis of regulatory elements of γ globin gene promoter, Aγ gene constructs carrying promoter truncations that have been previously analyzed in transgenic mice were used for production of stably transfected mouse erythroleukemia (MEL) cell clones and pools. We found that constructs, which contain a microlocus control region (μLCR) that efficiently protects globin gene expression from the effects of the position of integration in transgenic mice, display position-dependent globin gene expression in MEL cell clones. Aγ globin gene expression among MEL cell clones carrying the μLCR(−201)Aγ and μLCR(−382)Aγ gene constructs ranged 15.5-fold and 17.6-fold, respectively, and there was no correlation between theAγ mRNA levels and the copies of the transgene (r= .28, P = .18). There was significant variation in per copy Aγ globin gene expression among MEL cell pools composed of 10 clones, but not among pools composed of 50 clones, indicating that position effects are averaged in pools composed by large numbers of clones. The overall pattern of Aγ globin gene expression in MEL cell pools resembled that observed in transgenic mice indicating that MEL cell transfections can be used in the study ofcis elements controlling γ globin gene expression. MEL cell transfections, however, are not appropriate for investigation of cis elements, which either sensitize or protect the globin transgenes from position effects. © 1998 by The American Society of Hematology.


Blood ◽  
2000 ◽  
Vol 96 (1) ◽  
pp. 334-339 ◽  
Author(s):  
E. Camilla Forsberg ◽  
Karen M. Downs ◽  
Emery H. Bresnick

The human β-globin locus control region (LCR) confers high-level, tissue-specific expression to the β-globin genes. Tandem Maf recognition elements (MAREs) within the hypersensitive site 2 (HS2) subregion of the LCR are important for the strong enhancer activity of the LCR. Multiple proteins are capable of interacting with these sites in vitro, including the erythroid cell- and megakaryocyte-specific transcription factor, NF-E2. The importance of NF-E2 for β-globin gene expression is evident in murine erythroleukemia cells lacking the p45 subunit of NF-E2. These CB3 cells have a severe defect in - and β-globin gene transcription, which can be restored by expression of NF-E2. However, mice nullizygous for p45 express nearly normal levels of β-globin. Thus, either a redundant factor(s) exists in mice that can functionally replace NF-E2, or NF-E2 does not function through the LCR to regulate β-globin gene expression. To address this issue, we asked whether NF-E2 binds directly to the tandem MAREs of HS2 in intact cells. Using a chromatin immunoprecipitation assay, we provide evidence for NF-E2 binding directly and specifically to HS2 in living erythroleukemia cells and in mouse fetal liver. The specific immunoisolation of HS2 sequences was dependent on the presence of p45 and on intact MAREs within HS2. These results support a direct role for NF-E2 in the regulation of β-globin gene expression through activation of the LCR.


2005 ◽  
Vol 72 (S1) ◽  
pp. 34-43 ◽  
Author(s):  
Tina Lenasi ◽  
Nadja Kokalj-Vokac ◽  
Mojca Narat ◽  
Antonella Baldi ◽  
Peter Dovc

Casein genes are expressed in a tissue-specific and highly coordinated manner. The main goals of casein gene promoter studies are to unravel cis- and trans-acting factors involved in the complex signalling pathway controlling milk production, and to explore the possibility of using these promoters for tissue-specific production of heterologous proteins in the mammary gland. Here we present a comparative study of the equine β-casein and κ-casein gene proximal promoters. In order to confirm the assumption that in the horse, as in other mammalian species, casein genes are organized in a cluster located on a single chromosome, we performed in situ hybridization of pro-metaphase chromosomes with two BAC clones containing different equine casein genes. Sequence analysis of the β-casein and κ-casein gene proximal promoters revealed binding sites for activators (STAT5, GRE, NF1, MAF) and repressors (YY1, PMF), characteristic for casein genes. The alignments of casein gene promoters revealed the highest sequence identity in the proximal promoter region between the equine and human β-casein gene promoters. We directly compared the activity of equine β-casein and κ-casein gene promoters in vitro using bovine mammary gland cell line BME-UV1. In this system, the κ-casein gene proximal promoter activated the reporter gene expression more efficiently than the β-casein gene promoter of approximately the same length. The 810 bp of β-casein promoter activated the reporter gene expression more efficiently than the long fragment (1920 bp) and the 1206 bp fragment of the same promoter, which included also 396 bp of 5′ UTR.


2006 ◽  
Vol 231 (3) ◽  
pp. 328-334 ◽  
Author(s):  
Patrick A. Navas ◽  
Qiliang Li ◽  
Kenneth R. Peterson ◽  
George Stamatoyannopoulos

A silencing element has been previously located upstream of the human ε-globin gene promoter using transient assays and transgenic mice carrying plasmid constructs in which the element has been deleted or its transcriptional motifs have been mutated. To investigate whether this element functions in the context of the whole β-globin locus, we analyzed ε-globin gene expression in transgenic mice carrying a deletion of the silencing element in the context of a 213-kilobase human β-globin yeast artificial chromosome (β-YAC). ε-Globin gene expression was measured during embryonic and fetal development and in adult mice. ε-mRNA levels in embryonic cells in Day 12 blood were as high as those measured in wild-type β-YAC controls, indicating that the deletion does not affect ε gene promoter function. ε-Globin gene expression was confined to the embryonic cells, indicating that deletion of this silencing element did not affect ε-globin developmental expression in the context of the β-YAC. These results suggest that in the context of the whole β-globin locus, other proximal and upstream ε gene promoter elements as well as competition by the downstream globin genes contribute to the silencing of the ε-globin gene in the cells of definitive erythropoiesis.


Blood ◽  
1997 ◽  
Vol 90 (11) ◽  
pp. 4602-4609 ◽  
Author(s):  
Susanna Porcu ◽  
Michael Kitamura ◽  
Ewa Witkowska ◽  
Zemin Zhang ◽  
Annick Mutero ◽  
...  

Abstract The human β globin locus spans an 80-kb chromosomal region encompassing both the five expressed globin genes and the cis-acting elements that direct their stage-specific expression during ontogeny. Sequences proximal to the genes and in the locus control region, 60 kb upstream of the adult β globin gene, are required for developmental regulation. Transgenic studies have shown that altering the structural organization of the locus disrupts the normal pattern of globin gene regulation. Procedures for introducing yeast artificial chromosomes (YACs) containing large genetic loci now make it possible to define the sequences required for stage-restricted gene expression in constructs that preserve the integrity of the β globin locus. We demonstrate that independent YAC transgenic lines exhibit remarkably similar patterns of globin gene expression during development. The switch from γ to β globin predominant expression occurs between day 11.5 and 12.5 of gestation, with no more than twofold differences in human β globin mRNA levels between lines. Human β globin mRNA levels were twofold to fourfold lower than that of mouse βmaj, revealing potentially significant differences in the regulatory sequences of the two loci. These findings provide an important basis for studying regulatory elements within the β globin locus.


Blood ◽  
2007 ◽  
Vol 110 (9) ◽  
pp. 3391-3397 ◽  
Author(s):  
Hassana Fathallah ◽  
Rona S. Weinberg ◽  
Yelena Galperin ◽  
Millicent Sutton ◽  
George F. Atweh

Abstract Butyrate is a prototype of histone deacetylase inhibitors that is believed to reactivate silent genes by inducing epigenetic modifications. Although butyrate was shown to induce fetal hemoglobin (HbF) production in patients with hemoglobin disorders, the mechanism of this induction has not been fully elucidated. Our studies of the epigenetic configuration of the β-globin cluster suggest that DNA methylation and histone H3 acetylation are important for the regulation of developmental stage-specific expression of the β-like globin genes, whereas acetylation of both histones H3 and H4 seem to be important for the regulation of tissue-specific expression. These studies suggest that DNA methylation may be important for the silencing of the β-like globin genes in nonerythroid hematopoietic cells but may not be necessary for their silencing in nonhematopoietic cells. Furthermore, our studies demonstrate that butyrate exposure results in a true reversal of the normal developmental switch from γ- to β-globin expression. This is associated with increased histone acetylation and decreased DNA methylation of the γ-globin genes, with opposite changes in the β-globin gene. These studies provide strong support for the role of epigenetic modifications in the normal developmental and tissue-specific regulation of globin gene expression and in the butyrate-mediated pharmacologic induction of HbF production.


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