scholarly journals The Gene ssl3076 Encodes a Protein Mediating the Salt-Induced Expression of ggpS for the Biosynthesis of the Compatible Solute Glucosylglycerol in Synechocystis sp. Strain PCC 6803

2010 ◽  
Vol 192 (17) ◽  
pp. 4403-4412 ◽  
Author(s):  
Stephan Klähn ◽  
Antje Höhne ◽  
Elke Simon ◽  
Martin Hagemann
Keyword(s):  
Gene Expression ◽  
Reporter Gene ◽  
Transcriptional Start Site ◽  
Gene Promoter ◽  
Compatible Solute ◽  
Negative Regulator ◽  
Specific Gene ◽  
Reading Frame ◽  
Low Salt ◽  
Pcc 6803

ABSTRACT Acclimation to high salt concentrations involves concerted changes in gene expression. For the majority of salt-regulated genes, the mechanism underlying the induction process is not known. The gene ggpS (sll1566), which encodes the glucosylglycerol-phosphate synthase responsible for the synthesis of the compatible solute glucosylglycerol (GG), is specifically induced by salt in the cyanobacterial model strain Synechocystis sp. strain PCC 6803. To identify mechanisms mediating this salt-specific gene regulation, the ggpS promoter was analyzed in more detail. 5′ rapid amplification of cDNA ends (5′-RACE) experiments revealed that the adjacent open reading frame (ORF), which is annotated as unknown protein Ssl3076, overlaps with the transcriptional start site of the ggpS gene. Reporter gene expression analyses indicated an essential role for the intact ssl3076 gene in the salt-regulated transcription of a gfp reporter gene. Promoter fragments containing a mutated ssl3076 lost the salt regulation; similarly, a frameshift mutation in ssl3076 resulted in a high level of ggpS expression under low-salt conditions, thereby establishing this small ORF, named ggpR, as a negative regulator of ggpS. Interestingly, small ORFs were also found adjacent to ggpS genes in the genomes of other GG-accumulating cyanobacteria. These results suggest that the GgpR protein represses ggpS expression under low-salt conditions, whereas in salt-shocked and salt-acclimated cells a stress-proportional ggpS expression occurs, leading to GG accumulation.

scholarly journals Regulation of human heme oxygenase-1 gene expression under thermal stress

Blood ◽  
1996 ◽  
Vol 87 (12) ◽  
pp. 5074-5084 ◽  
Author(s):  
S Okinaga ◽  
K Takahashi ◽  
K Takeda ◽  
M Yoshizawa ◽  
H Fujita ◽  
...  
Keyword(s):  
Gene Expression ◽  
Thermal Stress ◽  
Heat Shock ◽  
Transient Expression ◽  
Reporter Gene ◽  
Heme Oxygenase ◽  
Gene Promoter ◽  
Heme Oxygenase 1 ◽  
Heat Shock Element ◽  
Hsp70 Mrna

Heme oxygenase-1 is an essential enzyme in heme catabolism, and its human gene promoter contains a putative heat shock element (HHO-HSE). This study was designed to analyze the regulation of human heme oxygenase-1 gene expression under thermal stress. The amounts of heme oxygenase-1 protein were not increased by heat shock (incubation at 42 degrees C) in human alveolar macrophages and in a human erythroblastic cell line, YN-1–0-A, whereas heat shock protein 70 (HSP70) was noticeably induced. However, heat shock factor does bind in vitro to HHO-HSE and the synthetic HHO-HSE by itself is sufficient to confer the increase in the transient expression of a reporter gene upon heat shock. The deletion of the sequence, located downstream from HHO-HSE, resulted in the activation of a reporter gene by heat shock. These results suggest that HHO-HSE is potentially functional but is repressed in vivo. Interestingly, heat shock abolished the remarkable increase in the levels of heme oxygenase-1 mRNA in YN-1–0-A cells treated with hemin or cadmium, in which HSP70 mRNA was noticeably induced. Furthermore, transient expression assays showed that heat shock inhibits the cadmium-mediated activation of the heme oxygenase-1 promoter, whereas the HSP70 gene promoter was activated upon heat shock. Such regulation of heme oxygenase-1 under thermal stress may be of physiologic significance in erythroid cells.

scholarly journals Extracellular Signal-Regulated Kinase Induces the Megakaryocyte GPIIb/CD41 Gene through MafB/Kreisler

2004 ◽  
Vol 24 (10) ◽  
pp. 4534-4545 ◽  
Author(s):  
Joel R. Sevinsky ◽  
Anne M. Whalen ◽  
Natalie G. Ahn
Keyword(s):  
Gene Expression ◽  
Mammalian Cells ◽  
Transcriptional Start Site ◽  
Dominant Negative ◽  
Proximal Promoter ◽  
Specific Gene ◽  
Promoter Regulation ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal ◽  
Megakaryocyte Differentiation

ABSTRACT Extracellular signal-regulated kinase (ERK) facilitates cell cycle progression in most mammalian cells, but in certain cell types prolonged signaling through this pathway promotes differentiation and lineage-specific gene expression through mechanisms that are poorly understood. Here, we characterize the transcriptional regulation of platelet GPIIb integrin (CD41) by ERK during megakaryocyte differentiation. ERK-dependent transactivation involves the proximal promoter of GPIIb within 114 bp upstream of the transcriptional start site. GATA, Ets, and Sp1 consensus sequences within this region are each necessary and function combinatorially in ERK-activated transcription. MafB/Kreisler is induced in response to ERK and synergizes with GATA and Ets to enhance transcription from the proximal promoter. The requirement for MafB in promoter regulation is demonstrated by inhibition of transactivation following dominant-negative or antisense suppression of MafB function. Thus, ERK promotes megakaryocyte differentiation by coordinate regulation of nuclear factors that synergize in GPIIb promoter regulation. These results establish a novel role for MafB as a regulator of ERK-induced gene expression.

scholarly journals The matrix attachment region-binding protein SATB1 participates in negative regulation of tissue-specific gene expression.

1997 ◽  
Vol 17 (9) ◽  
pp. 5275-5287 ◽  
Author(s):  
J Liu ◽  
D Bramblett ◽  
Q Zhu ◽  
M Lozano ◽  
R Kobayashi ◽  
...  
Keyword(s):  
Gene Expression ◽  
Reporter Gene ◽  
Nuclear Matrix ◽  
Inverted Repeat ◽  
Binding Proteins ◽  
Binding Protein ◽  
Specific Gene ◽  
Lymphoid Tissues ◽  
Tissue Specific ◽  
Mmtv Ltr

The nuclear matrix has been implicated in several cellular processes, including DNA replication, transcription, and RNA processing. In particular, transcriptional regulation is believed to be accomplished by binding of chromatin loops to the nuclear matrix and by the concentration of specific transcription factors near these matrix attachment regions (MARs). A number of MAR-binding proteins have been identified, but few have been directly linked to tissue-specific transcription. Recently, we have identified two cellular protein complexes (NBP and UBP) that bind to a region of the mouse mammary tumor virus (MMTV) long terminal repeat (LTR) previously shown to contain at least two negative regulatory elements (NREs) termed the promoter-proximal and promoter-distal NREs. These NREs are absent from MMTV strains that cause T-cell lymphomas instead of mammary carcinomas. We show here that NBP binds to a 22-bp sequence containing an imperfect inverted repeat in the promoter-proximal NRE. Previous data showed that a mutation (p924) within the inverted repeat elevated basal transcription from the MMTV promoter and destabilized the binding of NBP, but not UBP, to the proximal NRE. By using conventional and affinity methods to purify NBP from rat thymic nuclear extracts, we obtained a single major protein of 115 kDa that was identified by protease digestion and partial sequencing analysis as the nuclear matrix-binding protein special AT-rich sequence-binding protein 1 (SATB1). Antibody ablation, distamycin inhibition of binding, renaturation and competition experiments, and tissue distribution data all confirmed that the NBP complex contained SATB1. Similar types of experiments were used to show that the UBP complex contained the homeodomain protein Cux/CDP that binds the MAR of the intronic heavy-chain immunoglobulin enhancer. By using the p924 mutation within the MMTV LTR upstream of the chloramphenicol acetyltransferase gene, we generated two strains of transgenic mice that had a dramatic elevation of reporter gene expression in lymphoid tissues compared with reporter gene expression in mice expressing wild-type LTR constructs. Thus, the 924 mutation in the SATB1-binding site dramatically elevated MMTV transcription in lymphoid tissues. These results and the ability of the proximal NRE in the MMTV LTR to bind to the nuclear matrix clearly demonstrate the role of MAR-binding proteins in tissue-specific gene regulation and in MMTV-induced oncogenesis.

scholarly journals Regulation of the furA and catC Operon, Encoding a Ferric Uptake Regulator Homologue and Catalase-Peroxidase, Respectively, in Streptomyces coelicolor A3(2)

2000 ◽  
Vol 182 (13) ◽  
pp. 3767-3774 ◽  
Author(s):  
Ji-Sook Hahn ◽  
So-Young Oh ◽  
Jung-Hye Roe
Keyword(s):  
Streptomyces Coelicolor ◽  
Transcriptional Start Site ◽  
Protein Product ◽  
Negative Regulator ◽  
Start Codon ◽  
Multicopy Plasmid ◽  
Ferric Uptake Regulator ◽  
Start Site ◽  
Reading Frame ◽  
Catalase Peroxidase

ABSTRACT We isolated the catC gene, encoding catalase-peroxidase in Streptomyces coelicolor, using sequence homology with the katG gene from Escherichia coli. Upstream of the catC gene, an open reading frame (furA) encoding a homologue of ferric uptake regulator (Fur) was identified. S1 mapping analysis indicated that the furA gene was cotranscribed with the catC gene. The transcriptional start site of the furA-catC mRNA was mapped to the translation start codon ATG of the furA gene. The putative promoter contains consensus −10 and −35 elements similar to those recognized by ςHrdB, the major sigma factor of S. coelicolor. The transcripts were produced maximally at late-exponential phase and decreased at the stationary phase in liquid culture. The change in the amount of mRNA was consistent with that of CatC protein and enzyme activity. When the furA gene was introduced into S. lividans on a multicopy plasmid, the increased production of catC transcripts and protein product at late growth phase was inhibited, implying a role for FurA as the negative regulator of the furA-catC operon. FurA protein bound to its own promoter region between −59 and −39 nucleotides from the transcription start site. The binding affinity of FurA increased under reducing conditions and in the presence of metals such as Ni2+, Mn2+, Zn2+, or Fe2+. Addition of these metals to the growth medium decreased the production of CatC protein, consistent with the role of FurA as a metal-dependent repressor.

scholarly journals Chromosomal Proteins HMGN3a and HMGN3b Regulate the Expression of Glycine Transporter 1

2004 ◽  
Vol 24 (9) ◽  
pp. 3747-3756 ◽  
Author(s):  
Katherine L. West ◽  
Meryl A. Castellini ◽  
Melinda K. Duncan ◽  
Michael Bustin
Keyword(s):  
Gene Expression ◽  
Expression Profiles ◽  
Transcriptional Start Site ◽  
Ectopic Expression ◽  
Gene Expression Profiles ◽  
Specific Gene ◽  
Glycine Transporter 1 ◽  
Glycine Transporter ◽  
Synaptic Junctions

ABSTRACT HMGN proteins promote chromatin unfolding, enhance access to nucleosomes, and modulate transcription from chromatin templates. It is not known whether they act indiscriminately as general modulators of transcription or whether they regulate specific gene expression. Here, we investigated the role of HMGN3, a recently discovered HMGN family member, in transcription in vivo. We created cell lines overexpressing HMGN3a or its splice variant, HMGN3b, and analyzed their gene expression profiles using microarrays and reverse transcriptase PCR. We found that ectopic expression of HMGN3a alters the expression of approximately 0.8% of genes. Both HMGN3a and HMGN3b upregulate the expression of the glycine transporter 1 gene (Glyt1). Glyt1 encodes a membrane transporter that regulates the glycine concentration in synaptic junctions. Both GLYT1 and HMGN3 are highly expressed in glia cells and the eye, and we show that both proteins are coexpressed in the retina. Chromatin immunoprecipitation assays showed that HMGN3 protein is recruited to a region of the Glyt1 gene encompassing the Glyt1a transcriptional start site. These results suggest that HMGN3 regulates Glyt1 expression and demonstrate that members of the HMGN family can regulate the transcription of specific genes.

GC-rich murine adenosine deaminase gene promoter supports diverse tissue-specific gene expression

1990 ◽  
Vol 16 (2) ◽  
pp. 129-141 ◽  
Author(s):  
Sikha Rauth ◽  
Keh-Gang Yang ◽  
Anita M. Seibold ◽  
Diane E. Ingolia ◽  
Susan R. Ross ◽  
...  
Keyword(s):  
Gene Expression ◽  
Adenosine Deaminase ◽  
Gene Promoter ◽  
Specific Gene ◽  
Tissue Specific ◽  
Tissue Specific Gene ◽  
Specific Gene Expression

Functional study of the equine β-casein and κ-casein gene promoters

2005 ◽  
Vol 72 (S1) ◽  
pp. 34-43 ◽  
Author(s):  
Tina Lenasi ◽  
Nadja Kokalj-Vokac ◽  
Mojca Narat ◽  
Antonella Baldi ◽  
Peter Dovc
Keyword(s):  
Gene Expression ◽  
Mammary Gland ◽  
Reporter Gene ◽  
Gene Promoter ◽  
Reporter Gene Expression ◽  
Proximal Promoter ◽  
Gene Promoters ◽  
Tissue Specific ◽  
Casein Gene ◽  
Casein Genes

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.

scholarly journals Phosphatidylinositol 3-Kinase Is a Negative Regulator of Cellular Differentiation

1997 ◽  
Vol 137 (5) ◽  
pp. 1127-1136 ◽  
Author(s):  
Andrzej Ptasznik ◽  
Gillian M. Beattie ◽  
Martin I. Mally ◽  
Vincenzo Cirulli ◽  
Ana Lopez ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cellular Differentiation ◽  
Precursor Cells ◽  
Negative Regulator ◽  
Specific Gene ◽  
Phosphatidylinositol 3 Kinase ◽  
Specific Gene Expression ◽  
Endocrine Differentiation ◽  
Pi3k Activity ◽  
Phosphatidylinositol 3

Phosphatidylinositol 3-kinase (PI3K) has been shown to be an important mediator of intracellular signal transduction in mammalian cells. We show here, for the first time, that the blockade of PI3K activity in human fetal undifferentiated cells induced morphological and functional endocrine differentiation. This was associated with an increase in mRNA levels of insulin, glucagon, and somatostatin, as well as an increase in the insulin protein content and secretion in response to secretagogues. Blockade of PI3K also increased the proportion of pluripotent precursor cells coexpressing multiple hormones and the total number of terminally differentiated cells originating from these precursor cells. We examined whether any of the recently described modulators of endocrine differentiation could participate in regulating PI3K activity in fetal islet cells. The activity of PI3K was inversely correlated with the hepatocyte growth factor/scatter factor–induced downregulation or nicotinamideinduced upregulation of islet-specific gene expression, giving support to the role of PI3K, as a negative regulator of endocrine differentiation. In conclusion, our results provide a mechanism for the regulation of hormone-specific gene expression during human fetal neogenesis. They also suggest a novel function for PI3K, as a negative regulator of cellular differentiation.

scholarly journals The Transcription Factor Xrp1 is Required for PERK-Mediated Antioxidant Gene Induction in Drosophila

2021 ◽  
Author(s):  
Brian Brown ◽  
Sahana Mitra ◽  
Finnegan D Roach ◽  
Deepika Vasudevan ◽  
Hyung Don Ryoo
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
Upstream Open Reading Frame ◽  
Bzip Transcription Factor ◽  
Specific Gene ◽  
Antioxidant Genes ◽  
Reading Frame ◽  
Protein Levels ◽  
Signaling Axis ◽  
The Unfolded Protein Response

PERK is an endoplasmic reticulum (ER) transmembrane sensor that phosphorylates eIF2a to initiate the Unfolded Protein Response (UPR). eIF2a phosphorylation promotes stress-responsive gene expression most notably through the transcription factor ATF4 that contains a regulatory 5′ leader. Possible PERK effectors other than ATF4 remain poorly understood. Here, we report that the bZIP transcription factor Xrp1 is required for ATF4-independent PERK signaling. Cell type-specific gene expression profiling in Drosophila indicated that delta-family glutathione-S-transferases (gstD) are prominently induced by the UPR-activating transgene Rh1G69D. Perk was necessary and sufficient for such gstD induction, but ATF4 was not required. Instead, Perk and other regulators of eIF2a phosphorylation regulated Xrp1 protein levels to induce gstDs. The Xrp1 5′ leader has a conserved upstream Open Reading Frame (uORF) analogous to those that regulate ATF4 translation. The gstD-GFP reporter induction required putative Xrp1 binding sites. These results indicate that antioxidant genes are highly induced by a previously unrecognized UPR signaling axis consisting of PERK and Xrp1.

scholarly journals Temporally and spatially controllable gene expression and knockout in mouse urothelium

2010 ◽  
Vol 299 (2) ◽  
pp. F387-F395 ◽  
Author(s):  
Haiping Zhou ◽  
Yan Liu ◽  
Feng He ◽  
Lan Mo ◽  
Tung-Tien Sun ◽  
...  
Keyword(s):  
Gene Expression ◽  
Reporter Gene ◽  
Adult Mouse ◽  
Background Activity ◽  
Gene Overexpression ◽  
Specific Gene ◽  
Urothelial Cells ◽  
Disease Pathogenesis ◽  
Specific Gene Expression ◽  
Mouse Urothelium

Urothelium that lines almost the entire urinary tract performs important functions and is prone to assaults by urinary microbials, metabolites, and carcinogens. To improve our understanding of urothelial physiology and disease pathogenesis, we sought to develop two novel transgenic systems, one that would allow inducible and urothelium-specific gene expression, and another that would allow inducible and urothelium-specific knockout. Toward this end, we combined the ability of the mouse uroplakin II promoter (mUPII) to drive urothelium-specific gene expression with a versatile tetracycline-mediated inducible system. We found that, when constructed under the control of mUPII, only a modified, reverse tetracycline trans-activator (rtTA-M2), but not its original version (rtTA), could efficiently trans-activate reporter gene expression in mouse urothelium on doxycycline (Dox) induction. The mUPII/rtTA-M2-inducible system retained its strict urothelial specificity, had no background activity in the absence of Dox, and responded rapidly to Dox administration. Using a reporter gene whose expression was secondarily controlled by histone remodeling, we were able to identify, colocalize with 5-bromo-2-deoxyuridine incorporation, and semiquantify newly divided urothelial cells. Finally, we established that, when combined with a Cre recombinase under the control of the tetracycline operon, the mUPII-driven rtTA-M2 could inducibly inactivate any gene of interest in mouse urothelium. The establishment of these two new transgenic mouse systems enables the manipulation of gene expression and/or inactivation in adult mouse urothelium at any given time, thus minimizing potential compensatory effects due to gene overexpression or loss and allowing more accurate modeling of urothelial diseases than previously reported constitutive systems.

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