scholarly journals Identification of a Copper-Inducible Promoter for Use in Ectopic Expression in the Fungal Pathogen Histoplasma capsulatum

2006 ◽  
Vol 5 (6) ◽  
pp. 935-944 ◽  
Author(s):  
Dana Gebhart ◽  
Adam K. Bahrami ◽  
Anita Sil
Keyword(s):  
Gene Expression ◽  
Fungal Pathogen ◽  
Large Scale ◽  
Histoplasma Capsulatum ◽  
Fluorescent Protein ◽  
Efflux Pump ◽  
Regulatory Region ◽  
Ectopic Expression ◽  
Upstream Regulatory Region ◽  
Yeast Cultures

ABSTRACT Despite the existence of a number of genetic tools to study the fungal pathogen Histoplasma capsulatum, strategies for conditional gene expression have not been developed. We used microarray analysis to identify genes that are transcriptionally induced or repressed by the addition of copper sulfate (CuSO4) to H. capsulatum yeast cultures. One of these genes, CRP1, encodes a putative copper efflux pump that is significantly induced in the presence of CuSO4. The upstream regulatory region of CRP1 was sufficient to drive copper-regulated expression of two reporter genes, lacZ and the gene encoding green fluorescent protein. Microarray experiments were performed to determine a copper concentration that triggers accumulation of the CRP1 transcript without significant perturbation of global gene expression. These studies show that the CRP1 upstream regulatory region can be used for ectopic expression of heterologous genes in H. capsulatum. Furthermore, they demonstrate the strategic use of microarrays to identify conditional promoters that confer induction in the absence of large-scale shifts in gene expression.

scholarly journals Implementation of a CRISPR-Based System for Gene Regulation in Candida albicans

mSphere ◽  
2019 ◽  
Vol 4 (1) ◽  
Author(s):  
Elvira Román ◽  
Ioana Coman ◽  
Daniel Prieto ◽  
Rebeca Alonso-Monge ◽  
Jesús Pla
Keyword(s):  
Gene Expression ◽  
Candida Albicans ◽  
Protein Interactions ◽  
Transcriptional Activation ◽  
Fungal Pathogen ◽  
Rna Binding ◽  
Fluorescent Protein ◽  
Regulatory Region ◽  
Nuclease Activity ◽  
Content Type

ABSTRACT Clustered regularly interspaced short palindromic repeat (CRISPR) methodology is not only an efficient tool in gene editing but also an attractive platform to facilitate DNA, RNA, and protein interactions. We describe here the implementation of a CRISPR-based system to regulate expression in the clinically important yeast Candida albicans. By fusing an allele of Streptococcus pyogenes Cas9 devoid of nuclease activity to a transcriptional repressor (Nrg1) or activator (Gal4), we were able to show specific repression or activation of the tester gene CAT1, encoding the cytosolic catalase. We generated strains where a 1.6-kbp upstream regulatory region of CAT1 controls the expression of the green fluorescent protein (GFP) and demonstrated the functionality of the constructs by quantitative PCR (qPCR), flow cytometry, and analysis of sensitivity/resistance to hydrogen peroxide. Activation and repression were strongly dependent on the position of the complex in this regulatory region. We also improved transcriptional activation using an RNA scaffolding strategy to allow interaction of inactive variants of Cas9 (dCas9) with the RNA binding protein MCP (monocyte chemoattractant protein) fused to the VP64 activator. The strategy shown here may facilitate the analysis of complex regulatory traits in this fungal pathogen. IMPORTANCE CRISPR technology is a new and efficient way to edit genomes, but it is also an appealing way to regulate gene expression. We have implemented CRISPR as a gene expression platform in Candida albicans using fusions between a Cas9 inactive enzyme and specific repressors or activators and demonstrated its functionality. This will allow future manipulation of complex virulence pathways in this important fungal pathogen.

scholarly journals Synergistic activation of ADH2 expression is sensitive to upstream activation sequence 2 (UAS2) orientation, copy number and UAS1-UAS2 helical phasing.

1995 ◽  
Vol 15 (6) ◽  
pp. 3442-3449 ◽  
Author(s):  
M S Donoviel ◽  
N Kacherovsky ◽  
E T Young
Keyword(s):  
Gene Expression ◽  
Binding Site ◽  
Reporter Gene ◽  
Copy Number ◽  
Glucose Repression ◽  
Regulatory Protein ◽  
Regulatory Region ◽  
Upstream Regulatory Region ◽  
Specific Sequence

The alcohol dehydrogenase 2 (ADH2) gene of Saccharomyces cerevisiae is under stringent glucose repression. Two cis-acting upstream activation sequences (UAS) that function synergistically in the derepression of ADH2 gene expression have been identified. UAS1 is the binding site for the transcriptional regulator Adr1p. UAS2 has been shown to be important for ADH2 expression and confers glucose-regulated, ADR1-independent activity to a heterologous reporter gene. An analysis of point mutations within UAS2, in the context of the entire ADH2 upstream regulatory region, showed that the specific sequence of UAS2 is important for efficient derepression of ADH2, as would be expected if UAS2 were the binding site for a transcriptional regulatory protein. In the context of the ADH2 upstream regulatory region, including UAS1, working in concert with the ADH2 basal promoter elements, UAS2-dependent gene activation was dependent on orientation, copy number, and helix phase. Multimerization of UAS2, or its presence in reversed orientation, resulted in a decrease in ADH2 expression. In contrast, UAS2-dependent expression of a reporter gene containing the ADH2 basal promoter and coding sequence was enhanced by multimerization of UAS2 and was independent of UAS2 orientation. The reduced expression caused by multimerization of UAS2 in the native promoter was observed only in the presence of ADR1. Inhibition of UAS2-dependent gene expression by Adr1p was also observed with a UAS2-dependent ADH2 reporter gene. This inhibition increased with ADR1 copy number and required the DNA-binding activity of Adr1p. Specific but low-affinity binding of Adr1p to UAS2 in vitro was demonstrated, suggesting that the inhibition of UAS2-dependent gene expression observed in vivo could be a direct effect due to Adr1p binding to UAS2.

Hematopoietic regulatory domain of gata1 gene is positively regulated by GATA1 protein in zebrafish embryos

Development ◽  
2001 ◽  
Vol 128 (12) ◽  
pp. 2341-2350
Author(s):  
Makoto Kobayashi ◽  
Keizo Nishikawa ◽  
Masayuki Yamamoto
Keyword(s):  
Gene Expression ◽  
Reporter Gene ◽  
Regulatory Region ◽  
Ectopic Expression ◽  
Transgenic Fish ◽  
Functional Domain ◽  
Cis Acting ◽  
Gfp Reporter ◽  
Gata Motif

Expression of gata1 is regulated through multiple cis-acting GATA motifs. To elucidate regulatory mechanisms of the gata1 gene, we have used zebrafish. To this end, we isolated and analyzed zebrafish gata1 genomic DNA, which resulted in the discovery of a novel intron that was unknown in previous analyses. This intron corresponds to the first intron of other vertebrate Gata1 genes. GFP reporter analyses revealed that this intron and a distal double GATA motif in the regulatory region are important for the regulation of zebrafish gata1 gene expression. To examine whether GATA1 regulates its own gene expression, we microinjected into embryos a GFP reporter gene linked successively to the gata1 gene regulatory region and to GATA1 mRNA. Surprisingly, ectopic expression of the reporter gene was induced at the site of GATA1 overexpression and was dependent on the distal double GATA motif. Functional domain analyses using transgenic fish lines that harbor the gata1-GFP reporter construct revealed that both the N- and C-terminal zinc-finger domains of GATA1, hence intact GATA1 function, are required for the ectopic GFP expression. These results provide the first in vivo evidence that gata1 gene expression undergoes positive autoregulation.

Targeted modification of promoters

2021 ◽  
pp. 247-278
Author(s):  
Andika Gunadi ◽  
◽  
Ning Zhang ◽  
John J. Finer ◽  
◽  
...  
Keyword(s):  
Gene Expression ◽  
Genome Editing ◽  
Promoter Region ◽  
Regulatory Region ◽  
Regulatory Elements ◽  
Upstream Regulatory Region ◽  
Precise Control ◽  
Coding Regions ◽  
Gene Coding ◽  
Altered Regulation

Although most genome editing efforts focus on modifications to gene coding regions, this chapter emphasizes genome editing of the upstream regulatory regions. Thoughtful editing of the promoter region will ultimately lead to improved plants, modified for more precise control of the intensity and specificity of native gene expression. In this chapter, we present an overview of the promoter or upstream regulatory region of a gene, and describe how this sequence is defined and studied. We then describe how the composition and arrangements of cis-regulatory elements within the promoter and the leading intron associated with the promoter region have been studied using classical transgenic approaches to reveal what regulatory components might be suitable for genome editing approaches. Finally, we offer some suggestions for pursuit of promoter editing and gene expression modulation, which will eventually lead to modified plants with an altered regulation of native gene expression.

scholarly journals Role of the 5′ enhancer of the glutamine synthetase gene in its organ-specific expression

1997 ◽  
Vol 323 (3) ◽  
pp. 611-619 ◽  
Author(s):  
Heleen LIE-VENEMA ◽  
Piet A. J. DE BOER ◽  
Antoon F. M. MOORMAN ◽  
Wouter H. LAMERS
Keyword(s):  
Gene Expression ◽  
Skeletal Muscle ◽  
Gastrointestinal Tract ◽  
Glutamine Synthetase ◽  
Regulatory Element ◽  
Regulatory Region ◽  
Upstream Regulatory Region ◽  
Specific Expression ◽  
Organ Specific ◽  
Ribonuclease Protection

In mammals, glutamine synthetase (GS) is expressed in a large number of organs, but the precise regulation of its expression is still obscure. Therefore a detailed analysis of the activity of the upstream regulatory element of the GS gene in the transcriptional regulation of its expression was carried out in transgenic mice carrying the chloramphenicol acetyltransferase (CAT) gene under the control of the upstream regulatory region of the GS gene. CAT and GS mRNA expression were compared in liver, epididymis, lung, adipocytes, testis, kidney, skeletal muscle and gastrointestinal tract, both quantitatively by ribonuclease-protection analysis and topographically by in situ hybridization. It was found that the upstream regulatory region is active with respect both to the level and to the topography of GS gene expression in liver, epididymis, gastrointestinal tract (stomach, small intestine and colon) and skeletal muscle. On the other hand, in the kidney, brain, adipocytes, spleen, lung and testis, GS gene expression is not or only partly regulated by the 5´ enhancer. A second enhancer, identified within the first intron, may regulate GS expression in the latter organs. Furthermore, CAT expression in the brain did not co-localize with that of GS, showing that the 5´ regulatory region of the GS gene does not direct its expression to the astrocytes.

scholarly journals Application of RNA Interference Technology to Acroporid Juvenile Corals

2021 ◽  
Vol 8 ◽  
Author(s):  
Ikuko Yuyama ◽  
Tomihiko Higuchi ◽  
Michio Hidaka
Keyword(s):  
Gene Expression ◽  
Rna Interference ◽  
Stress Response ◽  
Large Scale ◽  
Elevated Temperatures ◽  
Fluorescent Protein ◽  
Fluorescence Emission ◽  
Pcr Analysis ◽  
Genes Encoding ◽  
Green Fluorescent

Numerous genes involved in calcification, algal endosymbiosis, and the stress response have been identified in corals by large-scale gene expression analysis, but functional analysis of those genes is lacking. There are few experimental examples of gene expression manipulation in corals, such as gene knockdown by RNA interference (RNAi). The purpose of this study is to establish an RNAi method for coral juveniles. As a first trial, the genes encoding green fluorescent protein (GFP, an endogenous fluorophore expressed by corals) and thioredoxin (TRX, a stress response gene) were selected for knockdown. Synthesized double-stranded RNAs (dsRNAs) corresponding to GFP and TRX were transformed into planula larvae by lipofection method to attempt RNAi. Real-time PCR analysis to verify knockdown showed that GFP and TRX expression levels tended to decrease with each dsRNA treatment (not significant). In addition, stress exposure experiments following RNAi treatment revealed that planulae with TRX knockdown exhibited increased mortality at elevated temperatures. In GFP-knockdown corals, decreased GFP fluorescence was observed. However, the effect of GFP-knockdown was confirmed only in the coral at the initial stages of larval metamorphosis into polyps, but not in planulae and 1 month-old budding polyps. This study showed that lipofection RNAi can be applied to coral planulae and polyps after settlement, and that this method provides a useful tool to modify expression of genes involved in stress tolerance and fluorescence emission of the corals.

Inclusion of HOXA Genes in Genetic and Biological Networks Defining Human Acute T-Cell Leukemia.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 1110-1110
Author(s):  
Jean Soulier ◽  
Emmanuelle Clappier ◽  
Jean-Michel Cayuela ◽  
Armelle Regnault ◽  
Marina Garcia-Peydro ◽  
...  
Keyword(s):  
Gene Expression ◽  
T Cell ◽  
Gene Cluster ◽  
Expression Analysis ◽  
Large Scale ◽  
Lymphoblastic Leukemia ◽  
Ectopic Expression ◽  
Molecular Networks ◽  
Human T Cell ◽  
Hoxa Genes

Abstract We have identified a new recurrent chromosomal translocation, targeting the major homeobox gene cluster HOXA in human T-cell acute lymphoblastic leukemia (T-ALL). Four cases were characterized using a combination of FISH, Southern blot, breakpoint region sequencing, and a large scale expression analysis of a series of T-ALL. Specific RQ-PCR analysis of the HOXA1 to HOXA13 transcripts showed that the whole HOXA gene cluster expression was dramatically deregulated in the HOXA-rearranged cases, and also in the MLL and CALM-AF10-related T-ALL, strongly suggesting that HOXA genes are oncogenic in these types of leukemia. The HOXA-rearranged cases were included in a general portrait of T-ALL based on large scale expression analysis, showing that a new homogeneous T-ALL subgroup is defined by this chromosomal rearrangement. Moreover, patterns of gene expression associated to the distinct T-ALL oncogenic subgroups were compared with gene expression in normal human thymic sub-populations (11 purified sub-populations). Inappropriate use or perturbation of some specific molecular networks involved in thymic differentiation could be detected in the T-ALL cells. Also, we found that abnormal, frequently ectopic, expression of at least one developmental gene, including HOXA, TLX1/HOX11, TLX3/HOX11L2 and a few more, could be identified in most of the T-ALL cases. Our data strongly support the view that the abnormal expression of developmental genes, including the prototypical major homeobox genes HOXA in some cases, is critical in T-ALL oncogenesis.

scholarly journals Ten-Eleven Translocation 1 (Tet1) Is Regulated by O-Linked N-Acetylglucosamine Transferase (Ogt) for Target Gene Repression in Mouse Embryonic Stem Cells

2013 ◽  
Vol 288 (29) ◽  
pp. 20776-20784 ◽  
Author(s):  
Feng-Tao Shi ◽  
Hyeung Kim ◽  
Weisi Lu ◽  
Quanyuan He ◽  
Dan Liu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Large Scale ◽  
Target Genes ◽  
Es Cells ◽  
Ectopic Expression ◽  
Embryonic Stem ◽  
Dna Demethylation ◽  
Mouse Es Cells ◽  
Chromatin Regulators ◽  
Glcnac Transferase

As a member of the Tet (Ten-eleven translocation) family proteins that can convert 5-methylcytosine (5mC) to 5-hydroxylmethylcytosine (5hmC), Tet1 has been implicated in regulating global DNA demethylation and gene expression. Tet1 is highly expressed in embryonic stem (ES) cells and appears primarily to repress developmental genes for maintaining pluripotency. To understand how Tet1 may regulate gene expression, we conducted large scale immunoprecipitation followed by mass spectrometry of endogenous Tet1 in mouse ES cells. We found that Tet1 could interact with multiple chromatin regulators, including Sin3A and NuRD complexes. In addition, we showed that Tet1 could also interact with the O-GlcNAc transferase (Ogt) and be O-GlcNAcylated. Depletion of Ogt led to reduced Tet1 and 5hmC levels on Tet1-target genes, whereas ectopic expression of wild-type but not enzymatically inactive Ogt increased Tet1 levels. Mutation of the putative O-GlcNAcylation site on Tet1 led to decreased O-GlcNAcylation and level of the Tet1 protein. Our results suggest that O-GlcNAcylation can positively regulate Tet1 protein concentration and indicate that Tet1-mediated 5hmC modification and target repression is controlled by Ogt.

Repression via the GATA box is essential for tissue-specific erythropoietin gene expression

Blood ◽  
2008 ◽  
Vol 111 (10) ◽  
pp. 5223-5232 ◽  
Author(s):  
Naoshi Obara ◽  
Norio Suzuki ◽  
Kibom Kim ◽  
Toshiro Nagasawa ◽  
Shigehiko Imagawa ◽  
...  
Keyword(s):  
Gene Expression ◽  
Fluorescent Protein ◽  
Ectopic Expression ◽  
Marker Genes ◽  
Central Vein ◽  
Specific Expression ◽  
Neuronal Marker ◽  
Nucleotide Mutation ◽  
Gata Box

Abstract In response to anemia, erythropoietin (Epo) gene transcription is markedly induced in the kidney and liver. To elucidate how Epo gene expression is regulated in vivo, we established transgenic mouse lines expressing green fluorescent protein (GFP) under the control of a 180-kb mouse Epo gene locus. GFP expression was induced by anemia or hypoxia specifically in peritubular interstitial cells of the kidney and hepatocytes surrounding the central vein. Surprisingly, renal Epo-producing cells had a neuronlike morphology and expressed neuronal marker genes. Furthermore, the regulatory mechanisms of Epo gene expression were explored using transgenes containing mutations in the GATA motif of the promoter region. A single nucleotide mutation in this motif resulted in constitutive ectopic expression of transgenic GFP in renal distal tubules, collecting ducts, and certain populations of epithelial cells in other tissues. Since both GATA-2 and GATA-3 bind to the GATA box in distal tubular cells, both factors are likely to repress constitutively ectopic Epo gene expression in these cells. Thus, GATA-based repression is essential for the inducible and cell type–specific expression of the Epo gene.

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