scholarly journals The presence of two distinct prolactin receptors in seabream with different tissue distribution patterns, signal transduction pathways and regulation of gene expression by steroid hormones

2007 ◽  
Vol 194 (2) ◽  
pp. 373-392 ◽  
Author(s):  
Xigui Huang ◽  
Baowei Jiao ◽  
Chun Kit Fung ◽  
Yong Zhang ◽  
Walter K K Ho ◽  
...  
Keyword(s):  
Gene Expression ◽  
Tissue Distribution ◽  
Steroid Hormones ◽  
Hormonal Regulation ◽  
Promoter Activity ◽  
Expression Patterns ◽  
Regulation Of Gene Expression ◽  
Gene Promoter ◽  
Prolactin Receptors ◽  
Black Seabream

Two prolactin receptors (PRLRs) encoded by two different genes were identified in the fugu and zebrafish genomes but not in the genomes of other vertebrates. Subsequently, two cDNA sequences corresponding to two PRLRs were identified in black seabream and Nile tilapia. Phylogenetic analysis of PRLR sequences in various vertebrates indicated that the coexistence of two PRLRs in a single species is a unique phenomenon in teleosts. Both PRLRs in teleosts (the classical one named as PRLR1, the newly identified one as PRLR2) resemble the long-form mammalian PRLRs. However, despite their overall structural similarities, the two PRLR subtypes in fish share very low amino acid similarities (about 30%), mainly due to differences in the intracellular domain. In particular, the Box 2 region and some intracellular tyrosine residues are missing in PRLR2. Tissue distribution study by real-time PCR in black seabream (sb) revealed that both receptors (sbPRLR1 and sbPRLR2) are widely expressed in different tissues. In gill, the expression level of sbPRLR2 is much higher than that of sbPRLR1. In the intestine, the expression of sbPRLR1 is higher than that of sbPRLR2. The expression levels of both receptors are relatively low in most other tissues, with sbPRLR1 generally higher than sbPRLR2. The sbPRLR1 and sbPRLR2 were functionally expressed in cultured human embryonic kidney 293 cells. Both receptors can activate the β-casein and c-fos promoters; however, only sbPRLR1 but not sbPRLR2 can activate the Spi promoter upon receptor stimulation in a ligand-specific manner. These results indicate that both receptors share some common functions but are distinctly different from each other in mobilizing post-receptor events. When challenged with different steroid hormones, the two PRLRs exhibited very different gene expression patterns in the seabream kidney. The sbPRLR1 expression was up-regulated by estradiol and cortisol, whereas testosterone had no significant effect. For sbPRLR2, its expression was down-regulated by estradiol and testosterone, while cortisol exerted no significant effect. The 5′-flanking regions of the sbPRLR1 and sbPRLR2 genes were cloned and the promoter activities were studied in transfected GAKS cells in the absence or presence of different steroid hormones. The results of the promoter studies were in general agreement with the in vivo hormonal regulation of gene expression results. The sbPRLR1 gene promoter activity was activated by estradiol and cortisol, but not by testosterone. In contrast, the sbPRLR2 gene promoter activity was inhibited by estradiol, cortisol, and testosterone.

scholarly journals Real-time imaging of gene promoter activity using an adenoviral reporter construct demonstrates transcriptional dynamics in normal anterior pituitary cells

2003 ◽  
Vol 178 (1) ◽  
pp. 61-69 ◽  
Author(s):  
JA Stirland ◽  
ZC Seymour ◽  
S Windeatt ◽  
AJ Norris ◽  
P Stanley ◽  
...  
Keyword(s):  
Gene Expression ◽  
Real Time ◽  
Cell Lines ◽  
Promoter Activity ◽  
Expression Patterns ◽  
Gene Promoter ◽  
Luciferase Reporter ◽  
Pituitary Cells ◽  
Clonal Cell ◽  
Clonal Cell Lines

Although analysis of luciferase activity using luminescence imaging has provided new insights into the dynamic regulation of gene expression in living tIssues, studies in vitro have relied on stably transfected clonal cell lines, limiting the choice of cell type and species, or DNA microinjection, which is arduous and highly selective. We report here the first use of a recombinant adenovirus in which the firefly luciferase reporter gene was regulated by the prolactin gene promoter, to study temporal dynamics of promoter activity. This vector was used to infect the pituitary GH3 cell line, and also primary cultures of Syrian hamster pituitary cells. We show that adenovirally transduced cells retained normal regulation of the promoter-reporter transgene by appropriate signals. Furthermore, microscopic imaging studies indicated that both clonal and primary pituitary cells were transduced efficiently, giving readily detectable luminescence signals in real-time over long periods. Finally, analysis of single-cell expression patterns indicated that prolactin promoter activity was highly dynamic with pulses in gene expression, revealing that the transcriptional instability seen in clonal cells is a feature of normal pituitary cells. Adenoviral vectors offer a valuable tool for studies of gene regulation where conventional transgenesis and clonal cell lines are not available.

scholarly journals Cell-type Specific Expression Quantitative Trait Loci Associated with Alzheimer Disease in Blood and Brain Tissue

2020 ◽  
Author(s):  
Devanshi Patel ◽  
Xiaoling Zhang ◽  
John J. Farrell ◽  
Jaeyoon Chung ◽  
Thor D. Stein ◽  
...  
Keyword(s):  
Gene Expression ◽  
Quantitative Trait ◽  
Expression Patterns ◽  
Regulation Of Gene Expression ◽  
Cell Types ◽  
Eqtl Analysis ◽  
Cell Type ◽  
Specific Expression ◽  
Cell Type Specific Expression ◽  
Cell Type Specific

ABSTRACTBecause regulation of gene expression is heritable and context-dependent, we investigated AD-related gene expression patterns in cell-types in blood and brain. Cis-expression quantitative trait locus (eQTL) mapping was performed genome-wide in blood from 5,257 Framingham Heart Study (FHS) participants and in brain donated by 475 Religious Orders Study/Memory & Aging Project (ROSMAP) participants. The association of gene expression with genotypes for all cis SNPs within 1Mb of genes was evaluated using linear regression models for unrelated subjects and linear mixed models for related subjects. Cell type-specific eQTL (ct-eQTL) models included an interaction term for expression of “proxy” genes that discriminate particular cell type. Ct-eQTL analysis identified 11,649 and 2,533 additional significant gene-SNP eQTL pairs in brain and blood, respectively, that were not detected in generic eQTL analysis. Of note, 386 unique target eGenes of significant eQTLs shared between blood and brain were enriched in apoptosis and Wnt signaling pathways. Five of these shared genes are established AD loci. The potential importance and relevance to AD of significant results in myeloid cell-types is supported by the observation that a large portion of GWS ct-eQTLs map within 1Mb of established AD loci and 58% (23/40) of the most significant eGenes in these eQTLs have previously been implicated in AD. This study identified cell-type specific expression patterns for established and potentially novel AD genes, found additional evidence for the role of myeloid cells in AD risk, and discovered potential novel blood and brain AD biomarkers that highlight the importance of cell-type specific analysis.

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 MKL-1 regulates the stem cell marker. CD44 in breast cancer cells

2019 ◽  
Vol 78 ◽  
pp. 01002
Author(s):  
Zhou-Tong Dai ◽  
Ao Yao ◽  
Yuan Xiang ◽  
Jia Peng Li ◽  
Wei Guo ◽  
...  
Keyword(s):  
Gene Expression ◽  
Malignant Tumors ◽  
Regulation Of Gene Expression ◽  
Gene Promoter ◽  
Expression Regulation ◽  
Stem Cell Marker ◽  
Luciferase Reporter ◽  
Regulation Mechanism ◽  
Luciferase Reporter Gene ◽  
Factors Affecting

CD44, cluster of differentiation 44 is a typical marker of stem cells. At present, it has been found that CD44 is prevalent in various human malignant tumors, but its expression regulation mechanism is still not clear. The initiation of gene expression, the modification of RNA levels, and the regulation of protein levels are the main factors affecting the expression level of genes, and the most critical one is the regulation of gene expression by signaling pathways. Up to now, there has been no report on the role of MKL-1 in the cloning of the cd44 promoter. Therefore, this study intends to clone the cd44 gene promoter, construct its luciferase reporter gene vector, transfect the MKL-1 overexpression vector, and analyze how it affects transcriptional activity, in order to further study the expression regulation of cd44. The mechanism provides a powerful tool in the future.

scholarly journals Comparative Genomics and Transcriptomics To Analyze Fruiting Body Development in Filamentous Ascomycetes

Genetics ◽  
2019 ◽  
Vol 213 (4) ◽  
pp. 1545-1563 ◽  
Author(s):  
Ramona Lütkenhaus ◽  
Stefanie Traeger ◽  
Jan Breuer ◽  
Laia Carreté ◽  
Alan Kuo ◽  
...  
Keyword(s):  
Gene Expression ◽  
Fruiting Body ◽  
Molecular Mechanisms ◽  
Expression Patterns ◽  
Regulation Of Gene Expression ◽  
Comparative Transcriptomics ◽  
Fruiting Bodies ◽  
Body Development ◽  
Fruiting Body Development ◽  
Genes Encoding

Many filamentous ascomycetes develop three-dimensional fruiting bodies for production and dispersal of sexual spores. Fruiting bodies are among the most complex structures differentiated by ascomycetes; however, the molecular mechanisms underlying this process are insufficiently understood. Previous comparative transcriptomics analyses of fruiting body development in different ascomycetes suggested that there might be a core set of genes that are transcriptionally regulated in a similar manner across species. Conserved patterns of gene expression can be indicative of functional relevance, and therefore such a set of genes might constitute promising candidates for functional analyses. In this study, we have sequenced the genome of the Pezizomycete Ascodesmis nigricans, and performed comparative transcriptomics of developing fruiting bodies of this fungus, the Pezizomycete Pyronema confluens, and the Sordariomycete Sordaria macrospora. With only 27 Mb, the A. nigricans genome is the smallest Pezizomycete genome sequenced to date. Comparative transcriptomics indicated that gene expression patterns in developing fruiting bodies of the three species are more similar to each other than to nonsexual hyphae of the same species. An analysis of 83 genes that are upregulated only during fruiting body development in all three species revealed 23 genes encoding proteins with predicted roles in vesicle transport, the endomembrane system, or transport across membranes, and 13 genes encoding proteins with predicted roles in chromatin organization or the regulation of gene expression. Among four genes chosen for functional analysis by deletion in S. macrospora, three were shown to be involved in fruiting body formation, including two predicted chromatin modifier genes.

scholarly journals Foxa3 (HNF-3γ) binds to and activates the rat proglucagon gene promoter but is not essential for proglucagon gene expression

2002 ◽  
Vol 366 (2) ◽  
pp. 633-641 ◽  
Author(s):  
Yuanfang LIU ◽  
Wei SHEN ◽  
Patricia L. BRUBAKER ◽  
Klaus H. KAESTNER ◽  
Daniel J. DRUCKER
Keyword(s):  
Gene Expression ◽  
Cell Lines ◽  
Promoter Activity ◽  
Gene Promoter ◽  
Forkhead Box ◽  
Mild Hypoglycaemia ◽  
Element Binding Protein ◽  
Prolonged Fast

Members of the Forkhead box a (Foxa) transcription factor family are expressed in the liver, pancreatic islets and intestine and both Foxa1 and Foxa2 regulate proglucagon gene transcription. As Foxa proteins exhibit overlapping DNA-binding specificities, we examined the role of Foxa3 [hepatocyte nuclear factor (HNF)-3γ] in control of proglucagon gene expression. Foxa3 was detected by reverse transcriptase PCR in glucagon-producing cell lines and binds to the rat proglucagon gene G2 promoter element in GLUTag enteroendocrine cells. Although Foxa3 increased rat proglucagon promoter activity in BHK fibroblasts, augmentation of Foxa3 expression did not increase proglucagon promoter activity in GLUTag cells. Furthermore, adenoviral Foxa3 expression did not affect endogenous proglucagon gene expression in islet or intestinal endocrine cell lines. Although Foxa3-/- mice exhibit mild hypoglycaemia during a prolonged fast, the levels of proglucagon-derived peptides and proglucagon mRNA transcripts were comparable in tissues from wild-type and Foxa3-/- mice. These findings identify Foxa3 as a member of the proglucagon gene G2 element binding-protein family that, unlike Foxa1, is not essential for control of islet or intestinal proglucagon gene expression in vivo.

scholarly journals A natural sequence consisting of overlapping glucocorticoid-responsive elements mediates glucocorticoid, but not androgen, regulation of gene expression

2000 ◽  
Vol 350 (1) ◽  
pp. 123-129 ◽  
Author(s):  
Charbel MASSAAD ◽  
Michèle GARLATTI ◽  
Elizabeth M. WILSON ◽  
Françoise CADEPOND ◽  
Robert BAROUKI
Keyword(s):  
Gene Expression ◽  
Thymidine Kinase ◽  
Transcriptional Activation ◽  
Regulation Of Gene Expression ◽  
Gene Promoter ◽  
Mobility Shift ◽  
Liver And Kidney ◽  
Androgen Regulation ◽  
Responsive Element ◽  
Half Site

Cytosolic aspartate aminotransferase (cAspAT) is regulated by glucocorticoids in rat liver and kidney. Part of this regulation is mediated by an unusual glucocorticoid-responsive element (GRE)-like sequence called GRE A. GRE A is composed of two overlapping imperfect GREs, each comprising a conserved half-site (half-sites 1 and 4 respectively) and a poorly conserved half-site (half-sites 2 and 3 respectively). The sequence binds co-operatively two dimers of the glucocorticoid receptor (GR) and mediates efficient glucocorticoid regulation of gene expression. Analysis of deletions of the cAspAT gene promoter and subcloning of GRE A upstream of the thymidine kinase promoter indicate that this sequence is responsive to glucocorticoids, but not to androgens. Electrophoretic mobility shift assays indicate that the GRE A unit does not bind the androgen receptor (AR). The modification of three nucleotides in the poorly conserved half-sites 2 and 3, converting GRE A into two overlapping high-affinity GREs (ov-cGRE), resulted in co-operative binding of the AR. Furthermore, ov-cGRE efficiently mediated androgen regulation of the thymidine kinase promoter. A single base modification in half-site 2 or 3 in GRE A allowed the binding of the AR as one or two dimers respectively, and restored transcriptional activation by androgens only in the latter case. Thus the poor affinity of the AR for half-sites 2 and 3 prevented its binding to GRE A, indicating that the overlapping GRE A sequence of the cAspAT gene promoter discriminates a glucocorticoid-mediated from an androgen-mediated response.

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