scholarly journals In vitro transcription from the human A gamma-globin gene promoter

Blood ◽  
1993 ◽  
Vol 82 (4) ◽  
pp. 1344-1350 ◽  
Author(s):  
M Castle ◽  
D O'Neill ◽  
A Bank
Keyword(s):  
Gene Transcription ◽  
Globin Gene ◽  
Gene Promoter ◽  
K562 Cells ◽  
In Vitro Transcription ◽  
Systematic Analysis ◽  
Gamma Globin ◽  
Octamer Motif

Abstract We report enhanced transcription from the human A gamma-globin gene promoter in nuclear extracts (NE) of erythroleukemia (K562) cells compared with that in HeLa NE. We do not observe differences in transcription levels in the two extracts with nonglobin promoter templates. Our findings, indicating preferential recognition of the globin gene promoter by nuclear factors in K562 cells, are consistent with results of studies previously reported by ourselves and others. A novel finding described here is that the addition of a double-stranded octamer motif oligonucleotide to K562 NE increases the level of transcription from the A gamma-globin gene promoter, suggesting a potential role for an octamer motif-binding factor in the repression of A gamma-globin gene transcription. A cosmid construct containing extensive human gamma- and beta-globin gene promoter and structural sequences as well as upstream control sequences also exhibits higher levels of globin gene transcription in K562 NE than in HeLa NE. Our demonstration of the feasibility of efficient, globin promoter-specific in vitro transcription of this complex template offers a novel approach for the systematic analysis of the effects of putative regulatory factors on globin gene expression in vitro in the context of a genetic environment approximating that found in vivo.

scholarly journals In vitro transcription from the human A gamma-globin gene promoter

Blood ◽  
1993 ◽  
Vol 82 (4) ◽  
pp. 1344-1350 ◽  
Author(s):  
M Castle ◽  
D O'Neill ◽  
A Bank
Keyword(s):  
Gene Transcription ◽  
Globin Gene ◽  
Gene Promoter ◽  
K562 Cells ◽  
In Vitro Transcription ◽  
Systematic Analysis ◽  
Gamma Globin ◽  
Octamer Motif

We report enhanced transcription from the human A gamma-globin gene promoter in nuclear extracts (NE) of erythroleukemia (K562) cells compared with that in HeLa NE. We do not observe differences in transcription levels in the two extracts with nonglobin promoter templates. Our findings, indicating preferential recognition of the globin gene promoter by nuclear factors in K562 cells, are consistent with results of studies previously reported by ourselves and others. A novel finding described here is that the addition of a double-stranded octamer motif oligonucleotide to K562 NE increases the level of transcription from the A gamma-globin gene promoter, suggesting a potential role for an octamer motif-binding factor in the repression of A gamma-globin gene transcription. A cosmid construct containing extensive human gamma- and beta-globin gene promoter and structural sequences as well as upstream control sequences also exhibits higher levels of globin gene transcription in K562 NE than in HeLa NE. Our demonstration of the feasibility of efficient, globin promoter-specific in vitro transcription of this complex template offers a novel approach for the systematic analysis of the effects of putative regulatory factors on globin gene expression in vitro in the context of a genetic environment approximating that found in vivo.

scholarly journals AUF-1 and YB-1 are critical determinants of β-globin mRNA expression in erythroid cells

Blood ◽  
2012 ◽  
Vol 119 (4) ◽  
pp. 1045-1053 ◽  
Author(s):  
Sebastiaan van Zalen ◽  
Grace R. Jeschke ◽  
Elizabeth O. Hexner ◽  
J. Eric Russell
Keyword(s):  
Posttranscriptional Regulation ◽  
Rna Binding ◽  
Globin Gene ◽  
K562 Cells ◽  
Erythroid Cells ◽  
Erythroid Progenitors ◽  
Globin Mrna ◽  
Affinity Enrichment

Abstract The normal accumulation of β-globin protein in terminally differentiating erythroid cells is critically dependent on the high stability of its encoding mRNA. The molecular basis for this property, though, is incompletely understood. Factors that regulate β-globin mRNA within the nucleus of early erythroid progenitors are unlikely to account for the constitutively high half-life of β-globin mRNA in the cytoplasm of their anucleate erythroid progeny. We conducted in vitro protein-RNA binding analyses that identified a cytoplasm-restricted β-globin messenger ribonucleoprotein (mRNP) complex in both cultured K562 cells and erythroid-differentiated human CD34+ cells. This novel mRNP targets a specific guanine-rich pentanucleotide in a region of the β-globin 3′untranslated region that has recently been implicated as a determinant of β-globin mRNA stability. Subsequent affinity-enrichment analyses identified AUF-1 and YB-1, 2 cytoplasmic proteins with well-established roles in RNA biology, as trans-acting components of the mRNP. Factor-depletion studies conducted in vivo demonstrated the importance of the mRNP to normal steady-state levels of β-globin mRNA in erythroid precursors. These data define a previously unrecognized mechanism for the posttranscriptional regulation of β-globin mRNA during normal erythropoiesis, providing new therapeutic targets for disorders of β-globin gene expression.

Point mutation associated with hereditary persistence of fetal hemoglobin decreases RNA polymerase III transcription upstream of the affected gamma-globin gene

1986 ◽  
Vol 6 (9) ◽  
pp. 3278-3282
Author(s):  
D P Carlson ◽  
J Ross
Keyword(s):  
Rna Polymerase ◽  
Globin Gene ◽  
Rna Polymerase Iii ◽  
Fetal Hemoglobin ◽  
In Vitro Transcription ◽  
Base Substitution ◽  
Gamma Globin ◽  
Polymerase Iii ◽  
Hemoglobin Production

A base substitution in the 5'-flanking region of a human fetal globin gene is associated with abnormal fetal hemoglobin production. It also reduces by 5- to 10-fold in vitro transcription of the gene by RNA polymerase III. We discuss potential links between polymerase III transcription and abnormal hemoglobin production.

scholarly journals Augmentation of gamma-globin gene promoter activity by carboxylic acids and components of the human beta-globin locus control region

Blood ◽  
1994 ◽  
Vol 84 (11) ◽  
pp. 3929-3935 ◽  
Author(s):  
S Safaya ◽  
A Ibrahim ◽  
RF Rieder
Keyword(s):  
Gene Expression ◽  
Organic Acids ◽  
Carboxylic Acids ◽  
Transient Expression ◽  
Promoter Activity ◽  
Globin Gene ◽  
Gene Promoter ◽  
K562 Cells ◽  
Hemoglobin Synthesis ◽  
Gamma Globin

Butyric acid increases fetal hemoglobin synthesis in adult animals and in erythroid cells in culture and induces the gamma-globin gene promoter in transient expression experiments in K562 cells (McDonagh KT, Nienhuis AW, Blood 78:255a, 1992 [abstr, suppl 1]). We compared the effect of butyrate and other short-chain carboxylic acids in transient expression studies with K562 cells using an expression plasmid bearing a luciferase reporter gene driven by the normal human A gamma-globin gene promoter. Butyrate (4 carbons) increased the activity of the human A gamma-globin gene promoter up to 123 times. Marked augmentation of the normal gamma-promoter activity was also noted with 5-carbon valeric acid (up to 394 times) and 3-carbon propionic acid (up to 129 times). The branched isobutyric acid as well as phenylacetate showed less ability to increase promoter activity. Addition of the tandemly repeated AP-1/NF-E2 (AP) enhancer sequences from hypersensitive site 2 (HS2) of the locus control region (LCR) increased gamma-promoter activity up to 24 times. Addition of a nearby 16-bp conserved motif (CM) in HS2 (Safaya S, Rieder RF, Blood 78:146a, 1992 [abstr, suppl 1]) to the AP-containing plasmid construct further increased gamma-promoter activity. In the presence of butyrate, the plasmid bearing both the AP and CM sequences showed gene expression up to 477 times greater than that of the basal gamma-promoter-driven luciferase plasmid in the absence of inducer. A plasmid bearing the herpes simplex thymidine kinase promoter was also tested and gene expression was markedly increased by the same organic acids. MEL cells responded to butyrate, valerate, and propionate with induction of hemoglobin synthesis. Responses to isobutyrate and 6-carbon caproate required higher concentrations of the compounds. Thus, other short-chain organic acids as well as butyrate increase gamma-promoter activity in the transient expression system, and this activity can be further augmented by incorporating LCR elements into the expression vector. Nonglobin promoters also respond to the same carboxylic acids.

scholarly journals Transcriptional initiation is controlled by upstream GC-box interactions in a TATAA-less promoter.

1990 ◽  
Vol 10 (12) ◽  
pp. 6632-6641 ◽  
Author(s):  
M C Blake ◽  
R C Jambou ◽  
A G Swick ◽  
J W Kahn ◽  
J C Azizkhan
Keyword(s):  
Dihydrofolate Reductase ◽  
Gene Promoter ◽  
In Vitro Transcription ◽  
Initiation Site ◽  
Start Site ◽  
Transcriptional Initiation ◽  
Reductase Gene ◽  
Gc Box

Numerous genes contain TATAA-less promoters, and the control of transcriptional initiation in this important promoter class is not understood. We have determined that protein-DNA interactions at three of the four proximal GC box sequence elements in one such promoter, that of the hamster dihydrofolate reductase gene, control initiation and relative use of the major and minor start sites. Our results indicate that although the GC boxes are apparently equivalent with respect to factor binding, they are not equivalent with respect to function. At least two properly positioned GC boxes were required for initiation of transcription. Abolishment of DNA-protein interaction by site-specific mutation of the most proximal GC box (box I) resulted in a fivefold decrease in transcription from the major initiation site and a threefold increase in heterogeneous transcripts initiating from the vicinity of the minor start site in vitro and in vivo. Mutations that separately abolished interactions at GC boxes II and III while leaving GC box I intact affected the relative utilization of both the major and minor initiation sites as well as transcriptional efficiency of the promoter template in in vitro transcription and transient expression assays. Interaction at GC box IV when the three proximal boxes were in a wild-type configuration had no effect on transcription of the dihydrofolate reductase gene promoter. Thus, GC box interactions not only are required for efficient transcription but also regulate start site utilization in this TATAA-less promoter.

scholarly journals Point mutation associated with hereditary persistence of fetal hemoglobin decreases RNA polymerase III transcription upstream of the affected gamma-globin gene.

1986 ◽  
Vol 6 (9) ◽  
pp. 3278-3282 ◽  
Author(s):  
D P Carlson ◽  
J Ross
Keyword(s):  
Rna Polymerase ◽  
Globin Gene ◽  
Rna Polymerase Iii ◽  
Fetal Hemoglobin ◽  
In Vitro Transcription ◽  
Base Substitution ◽  
Gamma Globin ◽  
Polymerase Iii ◽  
Hemoglobin Production

A base substitution in the 5'-flanking region of a human fetal globin gene is associated with abnormal fetal hemoglobin production. It also reduces by 5- to 10-fold in vitro transcription of the gene by RNA polymerase III. We discuss potential links between polymerase III transcription and abnormal hemoglobin production.

Regulation of the rat NHE3 gene promoter by sodium butyrate

2001 ◽  
Vol 281 (4) ◽  
pp. G947-G956 ◽  
Author(s):  
Pawel R. Kiela ◽  
Eric R. Hines ◽  
James F. Collins ◽  
Fayez K. Ghishan
Keyword(s):  
Gene Transcription ◽  
Transcriptional Activation ◽  
Hdac Inhibitor ◽  
Promoter Activity ◽  
Actinomycin D ◽  
Trichostatin A ◽  
Gene Promoter ◽  
Short Chain Fatty Acids

Short-chain fatty acids, and especially butyrate (NaB), stimulate sodium and water absorption by inducing colonic Na+/H+ exchange (NHE). NaB induces NHE3 activity and protein and mRNA expression both in vivo and in vitro. NaB, as a histone deacetylase (HDAC) inhibitor, regulates gene transcription. We therefore studied whether NaB regulates transcription of the rat NHE3 promoter in transiently transfected Caco-2 cells. NaB (5 mM) strongly stimulated reporter gene activity, and this stimulation was prevented with actinomycin D, indicating transcriptional activation. NaB effects on the NHE3 promoter depended on the activity of Ser/Thr kinases, in particular, protein kinase A (PKA). However, PKA stimulation alone did not have an effect on promoter activity, and it did not act synergistically with NaB. Another HDAC inhibitor, Trichostatin A (TSA), stimulated NHE3 promoter in a Ser/Thr kinase-independent fashion. The putative NaB-responsive elements were localized within −320/−34 bp of the NHE3 promoter. These findings suggest that PKA mediates NaB effects on NHE3 gene transcription and that the mechanism of NaB action is different from that of TSA.

scholarly journals Methylation-enhanced binding of Sp1 to the stage selector element of the human gamma-globin gene promoter may regulate development specificity of expression.

1993 ◽  
Vol 13 (6) ◽  
pp. 3272-3281 ◽  
Author(s):  
S M Jane ◽  
D L Gumucio ◽  
P A Ney ◽  
J M Cunningham ◽  
A W Nienhuis
Keyword(s):  
De Novo ◽  
Globin Gene ◽  
Consensus Sequence ◽  
Gene Promoter ◽  
K562 Cells ◽  
Erythroid Cells ◽  
Mobility Shift ◽  
Cpg Dinucleotides ◽  
Gamma Globin ◽  
Preferential Binding

The human gamma-globin gene promoter contains a stage selector element (SSE) responsible for preferential interaction of the promoter with a powerful erythroid-specific enhancer in the fetal developmental stage (S.M. Jane, P.A. Ney, E.F. Vanin, D.L. Gumucio, and A.W. Nienhuis. EMBO J. 11:2691-2699, 1992). The element binds two proteins, the ubiquitous activator Sp1 and a protein previously known as -50 gamma and now named the stage selector protein (SSP). Binding of the second protein correlates with SSE activity in transient-transfection assays. We now report that a de novo binding site for the SSP is created by the -202(C-->G) mutation that causes hereditary persistence of fetal hemoglobin (HPFH). This site functions in an analogous manner to the SSE in hybrid beta-promoter/reporter gene constructs transfected into K562 cells. In contrast, the wild-type -202 sequence, which fails to bind the SSP, is incapable of activating the beta-gene promoter. Both the -50 and -202 HPFH sites for SSP binding overlap a consensus sequence for the transcriptional regulator Sp1. In addition, both sites contain CpG dinucleotides that are contact bases for SSP. Since the gamma promoter is known to be hypomethylated in fetal cells but fully methylated at CpG residues in adult erythroid cells, we examined the effects of this DNA modification on protein binding to the two regions. Gel mobility shift assays with nuclear extract from K562 cells (which contain both Sp1 and SSP) demonstrate preferential binding of SSP to the SSE and HPFH sites under conditions in which probe was limiting. Methylation of the CpG residues reverses this preference only in the SSE site, with a marked increase in the binding of Sp1 at the expense of the SSP. Purified Sp1 binds with 10-fold higher affinity to the methylated than to the nonmethylated -50 probe but with the same affinity to the -202 HPFH probe. The methylation-induced preferential binding of Sp1 to the SSE at the expense of SSP may be part of the mechanism by which the gamma genes are repressed in normal adult erythroid cells. In cells containing the -202 HPFH mutation, the inability of Sp1 to displace SSP in the methylated state may explain the persistence of gamma-promoter activity and gamma-gene expression observed in adults with this mutation.

scholarly journals Yeast TFIID Serves as a Coactivator for Rap1p by Direct Protein-Protein Interaction

2006 ◽  
Vol 27 (1) ◽  
pp. 297-311 ◽  
Author(s):  
Krassimira A. Garbett ◽  
Manish K. Tripathi ◽  
Belgin Cencki ◽  
Justin H. Layer ◽  
P. Anthony Weil
Keyword(s):  
Gene Expression ◽  
Saccharomyces Cerevisiae ◽  
Gene Transcription ◽  
In Vitro Transcription ◽  
Tata Binding Protein ◽  
In Vivo Studies ◽  
Activator Protein 1 ◽  
Protein Protein Interaction

ABSTRACT In vivo studies have previously shown that Saccharomyces cerevisiae ribosomal protein (RP) gene expression is controlled by the transcription factor repressor activator protein 1 (Rap1p) in a TFIID-dependent fashion. Here we have tested the hypothesis that yeast TFIID serves as a coactivator for RP gene transcription by directly interacting with Rap1p. We have found that purified recombinant Rap1p specifically interacts with purified TFIID in pull-down assays, and we have mapped the domains of Rap1p and subunits of TFIID responsible. In vitro transcription of a UASRAP1 enhancer-driven reporter gene requires both Rap1p and TFIID and is independent of the Fhl1p-Ifh1p coregulator. UASRAP1 enhancer-driven transactivation in extracts depleted of both Rap1p and TFIID is efficiently rescued by addition of physiological amounts of these two purified factors but not TATA-binding protein. We conclude that Rap1p and TFIID directly interact and that this interaction contributes importantly to RP gene transcription.

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