Prorenin and gene activation

1991 ◽  
Vol 69 (9) ◽  
pp. 1367-1374 ◽  
Author(s):  
Brian J. Morris ◽  
D. Lynne Smith
Keyword(s):  
Transient Expression ◽  
Hela Cells ◽  
Regulatory Element ◽  
Gene Activation ◽  
Regulatory Elements ◽  
Positive Control ◽  
Binding Activity ◽  
Transient Expression Assay ◽  
Nuclear Extracts

After the discovery of an inactive, putative renin precursor that could be proteolytically activated, and the proteases involved in vivo, Morris and co-workers directly demonstrated that renin is indeed synthesized as a "pro" form, and from genetic coding sequences they provided the structure of human prorenin. The gene is inactive and must be activated in prorenin-synthesizing tissues. To study the mechanism involved, we have performed transient expression analyses of putative regulatory DNA of the human gene (REN). 5′-Flanking DNA, extending from residue −144 to −2400, was linked to a reporter gene, viz. that for chloramphenicol acetyl transferase (CAT), and its ability to drive a heterologous (thymidine kinase, tk) promoter was examined by transfecting plasmid constructs into ceils in culture and measuring CAT activity 48 h later. Because suitable renin-synthesizing cells were not available, choriocarcinoma (JEG-3) and cervical carcinoma (HeLa) cells were used. Although this DNA caused a reduction in CAT activity relative to the positive control, examination of a range of subfragments suggested that the −2400 to −144 region did not contain negative regulatory elements. In contrast, all fragments containing the −149 to +13 DNA segment gave CAT activities that were lower than the promoterless control. Together, the data were consistent with the presence of negative regulatory element(s) in that fragment of DNA that contained the REN promoter. On the basis of mouse gene studies, it has been suggested that the inactivity of the renin gene in tissues that do not synthesize prorenin is not due to repression, but rather, cells that do express the gene may possess unique trans-acting factor(s) that stimulate enhancer(s) in the renin DNA, therefore activating the renin promoter. Nuclear extracts of JEG-3, but not HeLa, cells contained a binding activity for the −340 to −192 segment, but the relationship, if any, of this to the model proposed is unclear. Thus, having demonstrated the synthesis, structure, and activation of prorenin, the mechanism of activation of the gene represents the next challenge.Key words: gene regulation, transient expression assay, JEG-3 ceils, HeLa cells, prorenin.

Regulatory elements mediating transcription from the Drosophila melanogaster actin 5C proximal promoter

1990 ◽  
Vol 10 (1) ◽  
pp. 206-216
Author(s):  
Y T Chung ◽  
E B Keller
Keyword(s):  
Drosophila Melanogaster ◽  
Transient Expression ◽  
Promoter Activity ◽  
Regulatory Element ◽  
Regulatory Elements ◽  
Proximal Promoter ◽  
Base Pairs ◽  
Chloramphenicol Acetyltransferase Gene ◽  
Constitutive Synthesis

The major cytoskeletal actin gene of Drosophila melanogaster, the actin 5C gene, has two promoters, the proximal one of which controls constitutive synthesis of actin in all growing tissues. To locate regulatory elements required for constitutive activity of the proximal promoter, mutants of this promoter were fused to the bacterial chloramphenicol acetyltransferase gene and assayed for transient expression activity in cultured Drosophila embryonic Schneider line 2 cells. An essential regulatory element has been located 313 base pairs upstream from the cap site. Deletion of this element lowered expression to one-third of the wild-type level. The element has the sequence AAGTTGTAGTTG, as shown by protein-binding footprinting with the reagent methidiumpropyl-EDTA-Fe(II). This element is probably not a general one, since it was not detected in a search of the published 5'-flanking sequences of 27 Drosophila genes. In addition to this regulatory element, there are five GAGA elements in the actin 5C proximal promoter, some or all of which are essential for the promoter activity as shown by an in vivo competition assay. Although this promoter has no classical TATA element, there is an essential promoter region about 35 base pairs upstream from the cap site that could be a TATA surrogate. The promoter also shows sequences homologous to the alcohol dehydrogenase factor 1-binding site and to the core of the vertebrate serum response element, but mutations of these sites did not affect promoter activity in transient expression assays.

scholarly journals Regulatory elements mediating transcription from the Drosophila melanogaster actin 5C proximal promoter.

1990 ◽  
Vol 10 (1) ◽  
pp. 206-216 ◽  
Author(s):  
Y T Chung ◽  
E B Keller
Keyword(s):  
Drosophila Melanogaster ◽  
Transient Expression ◽  
Promoter Activity ◽  
Regulatory Element ◽  
Regulatory Elements ◽  
Proximal Promoter ◽  
Base Pairs ◽  
Chloramphenicol Acetyltransferase Gene ◽  
Constitutive Synthesis

The major cytoskeletal actin gene of Drosophila melanogaster, the actin 5C gene, has two promoters, the proximal one of which controls constitutive synthesis of actin in all growing tissues. To locate regulatory elements required for constitutive activity of the proximal promoter, mutants of this promoter were fused to the bacterial chloramphenicol acetyltransferase gene and assayed for transient expression activity in cultured Drosophila embryonic Schneider line 2 cells. An essential regulatory element has been located 313 base pairs upstream from the cap site. Deletion of this element lowered expression to one-third of the wild-type level. The element has the sequence AAGTTGTAGTTG, as shown by protein-binding footprinting with the reagent methidiumpropyl-EDTA-Fe(II). This element is probably not a general one, since it was not detected in a search of the published 5'-flanking sequences of 27 Drosophila genes. In addition to this regulatory element, there are five GAGA elements in the actin 5C proximal promoter, some or all of which are essential for the promoter activity as shown by an in vivo competition assay. Although this promoter has no classical TATA element, there is an essential promoter region about 35 base pairs upstream from the cap site that could be a TATA surrogate. The promoter also shows sequences homologous to the alcohol dehydrogenase factor 1-binding site and to the core of the vertebrate serum response element, but mutations of these sites did not affect promoter activity in transient expression assays.

The phylogenetically invariant ACAGAGA and AGC sequences of U6 small nuclear RNA are more tolerant of mutation in human cells than in Saccharomyces cerevisiae

1993 ◽  
Vol 13 (9) ◽  
pp. 5377-5382
Author(s):  
B Datta ◽  
A M Weiner
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Transient Expression ◽  
Human Cells ◽  
Mrna Splicing ◽  
Small Nuclear Rna ◽  
Transient Expression Assay ◽  
U6 Snrna ◽  
Nuclear Rna

U6 small nuclear RNA (snRNA) is the most highly conserved of the five spliceosomal snRNAs that participate in nuclear mRNA splicing. The proposal that U6 snRNA plays a key catalytic role in splicing [D. Brow and C. Guthrie, Nature (London) 337:14-15, 1989] is supported by the phylogenetic conservation of U6, the sensitivity of U6 to mutation, cross-linking of U6 to the vicinity of the 5' splice site, and genetic evidence for extensive base pairing between U2 and U6 snRNAs. We chose to mutate the phylogenetically invariant 41-ACAGAGA-47 and 53-AGC-55 sequences of human U6 because certain point mutations within the homologous regions of Saccharomyces cerevisiae U6 selectively block the first or second step of mRNA splicing. We found that both sequences are more tolerant to mutation in human cells (assayed by transient expression in vivo) than in S. cerevisiae (assayed by effects on growth or in vitro splicing). These differences may reflect different rate-limiting steps in the particular assays used or differential reliance on redundant RNA-RNA or RNA-protein interactions. The ability of mutations in U6 nucleotides A-45 and A-53 to selectively block step 2 of splicing in S. cerevisiae had previously been construed as evidence that these residues might participate directly in the second chemical step of splicing; an indirect, structural role seems more likely because the equivalent mutations have no obvious phenotype in the human transient expression assay.

Transient expression of a mouse alpha-fetoprotein minigene: deletion analyses of promoter function

1983 ◽  
Vol 3 (7) ◽  
pp. 1295-1309
Author(s):  
R W Scott ◽  
S M Tilghman
Keyword(s):  
Transient Expression ◽  
Hela Cells ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
Alpha Fetoprotein ◽  
Tata Box ◽  
Deletion Mutants ◽  
Promoter Function ◽  
Flanking Region

The constitutive transcription of a mouse alpha-fetoprotein (AFP) minigene was examined during the transient expression of AFP-simian virus 40-pBR322 recombinant DNAs introduced into HeLa cells by Ca3(PO4)2 precipitation. We tested three constructs, each of which contains the AFP minigene and pBR322 DNAs inserted in the late region of simian virus 40 and found that the relative efficiency of AFP gene expression was dependent on the arrangement of the three DNA elements in the vector. The transcripts begin at the authentic AFP cap site and are properly spliced and polyadenylated. To define a sequence domain in the 5' flanking region of the AFP gene required for constitutive expression, sequential 5' deletion mutants of the AFP minigene were constructed and introduced into HeLa cells. All AFP deletion mutants which retained at least the TATA motif located 30 base pairs upstream from the cap site were capable of directing accurate and efficient AFP transcription. However, when the TATA sequence was deleted, no accurately initiated AFP transcripts were detected. These results are identical to those obtained from in vitro transcription of truncated AFP 5' deletion mutant templates assayed in HeLa cell extracts. The rate of AFP transcription in vivo was unaffected by deletion of DNA upstream of the AFP TATA box but was greatly affected by the distance between the simian virus 40 control region and the 5' end of the gene. The absence of any promoter activity upstream of the TATA box in this assay system is in contrast to what has been reported for several other eucaryotic structural genes in a variety of in vivo systems. A sequence comparison between the 5' flanking region of the AFP gene and these genes suggested that the AFP gene lacks those structural elements found to be important for constitutive transcription in vivo. Either the AFP gene lacks upstream promoter function in the 5' flanking DNA contained within the minigene, or the use of a viral vector in a heterologous system precludes its identification.

A Single Pitx1 Binding Site Is Essential for Activity of the LHβ Promoter in Transgenic Mice

2001 ◽  
Vol 15 (5) ◽  
pp. 734-746 ◽  
Author(s):  
Christine C. Quirk ◽  
Kristen L. Lozada ◽  
Ruth A. Keri ◽  
John H. Nilson
Keyword(s):  
Transgenic Mice ◽  
Binding Site ◽  
Cell Lines ◽  
Regulatory Element ◽  
Regulatory Elements ◽  
Vital Role ◽  
Proximal Region ◽  
Expression Vectors ◽  
Homeodomain Protein

Abstract Reproduction depends on regulated expression of the LHβ gene. Tandem copies of regulatory elements that bind early growth response protein 1 (Egr-1) and steroidogenic factor 1 (SF-1) are located in the proximal region of the LHβ promoter and make essential contributions to its activity as well as mediate responsiveness to GnRH. Located between these tandem elements is a single site capable of binding the homeodomain protein Pitx1. From studies that employ overexpression paradigms performed in heterologous cell lines, it appears that Egr-1, SF-1, and Pitx1 interact cooperatively through a mechanism that does not require the binding of Pitx1 to its site. Since the physiological ramifications of these overexpression studies remain unclear, we reassessed the requirement for a Pitx1 element in the promoter of the LHβ gene using homologous cell lines and transgenic mice, both of which obviate the need for overexpression of transcription factors. Our analysis indicated a striking requirement for the Pitx1 regulatory element. When assayed by transient transfection using a gonadotrope-derived cell line (LβT2), an LHβ promoter construct harboring a mutant Pitx1 element displayed attenuated transcriptional activity but retained responsiveness to GnRH. In contrast, analysis of wild-type and mutant expression vectors in transgenic mice indicated that LHβ promoter activity is completely dependent on the presence of a functional Pitx1 binding site. Indeed, the dependence on an intact Pitx1 binding site in transgenic mice is so strict that responsiveness to GnRH is also lost, suggesting that the mutant promoter is inactive. Collectively, our data reinforce the concept that activity of the LHβ promoter is determined, in part, through highly cooperative interactions between SF-1, Egr-1, and Pitx1. While Egr-1 can be regarded as a key downstream effector of GnRH, and Pitx1 as a critical partner that activates SF-1, our data firmly establish that the Pitx1 element plays a vital role in permitting these functions to occur in vivo.

Transducing positional information to the Hox genes: critical interaction of cdx gene products with position-sensitive regulatory elements

Development ◽  
1998 ◽  
Vol 125 (22) ◽  
pp. 4349-4358 ◽  
Author(s):  
J. Charite ◽  
W. de Graaff ◽  
D. Consten ◽  
M.J. Reijnen ◽  
J. Korving ◽  
...  
Keyword(s):  
Binding Sites ◽  
Hox Genes ◽  
Regulatory Element ◽  
Ectopic Expression ◽  
Positional Information ◽  
Regulatory Elements ◽  
Gene Products ◽  
Anteroposterior Patterning

Studies of pattern formation in the vertebrate central nervous system indicate that anteroposterior positional information is generated in the embryo by signalling gradients of an as yet unknown nature. We searched for transcription factors that transduce this information to the Hox genes. Based on the assumption that the activity levels of such factors might vary with position along the anteroposterior axis, we devised an in vivo assay to detect responsiveness of cis-acting sequences to such differentially active factors. We used this assay to analyze a Hoxb8 regulatory element, and detected the most pronounced response in a short stretch of DNA containing a cluster of potential CDX binding sites. We show that differentially expressed DNA binding proteins are present in gastrulating embryos that bind to these sites in vitro, that cdx gene products are among these, and that binding site mutations that abolish binding of these proteins completely destroy the ability of the regulatory element to drive regionally restricted expression in the embryo. Finally, we show that ectopic expression of cdx gene products anteriorizes expression of reporter transgenes driven by this regulatory element, as well as that of the endogenous Hoxb8 gene, in a manner that is consistent with them being essential transducers of positional information. These data suggest that, in contrast to Drosophila Caudal, vertebrate cdx gene products transduce positional information directly to the Hox genes, acting through CDX binding sites in their enhancers. This may represent the ancestral mode of action of caudal homologues, which are involved in anteroposterior patterning in organisms with widely divergent body plans and modes of development.

Drosophila transcriptional repressor protein that binds specifically to negative control elements in fat body enhancers

1992 ◽  
Vol 12 (9) ◽  
pp. 4093-4103
Author(s):  
D Falb ◽  
T Maniatis
Keyword(s):  
Binding Site ◽  
Fat Body ◽  
Regulatory Element ◽  
Negative Control ◽  
Nuclear Extracts ◽  
Eukaryotic Proteins ◽  
Adh Gene ◽  
A Site

Expression of the Drosophila melanogaster Adh gene in adults requires a fat body-specific enhancer called the Adh adult enhancer (AAE). We have identified a protein in Drosophila nuclear extracts that binds specifically to a site within the AAE (adult enhancer factor 1 [AEF-1]). In addition, we have shown that AEF-1 binds specifically to two other Drosophila fat body enhancers. Base substitutions in the AEF-1 binding site that disrupt AEF-1 binding in vitro result in a significant increase in the level of Adh expression in vivo. Thus, the AEF-1 binding site is a negative regulatory element within the AAE. A cDNA encoding the AEF-1 protein was isolated and shown to act as a repressor of the AAE in cotransfection studies. The AEF-1 protein contains four zinc fingers and an alanine-rich sequence. The latter motif is found in other eukaryotic proteins known to be transcriptional repressors.

scholarly journals Oleacein Prevents High Fat Diet-Induced A Diposity and Ameliorates Some Biochemical Parameters of Insulin Sensitivity in Mice

Nutrients ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1829 ◽  
Author(s):  
Lepore ◽  
Maggisano ◽  
Bulotta ◽  
Mignogna ◽  
Arcidiacono ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Insulin Sensitivity ◽  
High Fat Diet ◽  
Fatty Acid Synthase ◽  
Glucose Transporter ◽  
Regulatory Element ◽  
Regulatory Elements ◽  
High Fat

Oleacein is one of the most abundant polyphenolic compounds of olive oil, which has been shown to play a protective role against several metabolic abnormalities, including dyslipidemia, insulin resistance, and glucose intolerance. Herein, we investigated the effects of oleacein on certain markers of adipogenesis and insulin-resistance in vitro, in 3T3-L1 adipocytes, and in vivo in high-fat diet (HFD)-fed mice. During the differentiation process of 3T3-L1 preadipocytes into adipocytes, oleacein strongly inhibited lipid accumulation, and decreased protein levels of peroxisome proliferator-activated receptor gamma (PPARγ) and fatty acid synthase (FAS), while increasing Adiponectin levels. In vivo, treatment with oleacein of C57BL/6JOlaHsd mice fed with HFD for 5 and 13 weeks prevented the increase in adipocyte size and reduced the inflammatory infiltration of macrophages and lymphocytes in adipose tissue. These effects were accompanied by changes in the expression of adipose tissue-specific regulatory elements such as PPARγ, FAS, sterol regulatory element-binding transcription factor-1 (SREBP-1), and Adiponectin, while the expression of insulin-sensitive muscle/fat glucose transporter Glut-4 was restored in HFD-fed mice treated with oleacein. Collectively, our findings indicate that protection against HFD-induced adiposity by oleacein in mice is mediated by the modulation of regulators of adipogenesis. Protection against HFD-induced obesity is effective in improving peripheral insulin sensitivity.

Characterization of MAP kinase and PKC isoform and effect of ACE inhibition in hypertrophy in vivo

1999 ◽  
Vol 277 (5) ◽  
pp. H1808-H1816 ◽  
Author(s):  
L. Kim ◽  
T. Lee ◽  
J. Fu ◽  
M. E. Ritchie
Keyword(s):  
Map Kinase ◽  
Gene Activation ◽  
Pressure Overload ◽  
Ace Inhibition ◽  
Binding Activity ◽  
Sham Operation ◽  
Kinase Activation ◽  
Mitogen Activated Protein

Protein kinase C (PKC) and mitogen-activated protein (MAP) kinase activation appear important in conferring hypertrophy in vitro. However, the response of PKC and MAP kinase to stimuli known to induce hypertrophy in vivo has not been determined. We recently demonstrated that pressure-overload hypertrophy induced a transiently transfected gene driven by an hypertrophy responsive enhancer (HRE) through a marked increase in binding activity of its interacting nuclear factor (HRF). These data suggested that the HRE/HRF could serve as a target for evaluating the signal transduction events responsible for hypertrophy in vivo. Accordingly, we characterized MAP kinase and PKC isoform activation, injected HRE driven reporter gene expression, and HRF binding activity in rat hearts subjected to ascending aortic clipping or sham operation in the presence of the angiotensin-converting enzyme (ACE) inhibitor fosinopril, hydralazine, or no treatment. Analyses showed that PKC-ε and MAP kinase were acutely activated following ascending aortic ligature and that fosinopril significantly inhibited but did not completely abrogate PKC-ε and MAP kinase activation. However, fosinopril completely prevented pressure overload-mediated induction of HRE containing constructs and obviated increased HRF binding activity. These results suggest a direct relationship between ACE activity and HRE/HRF-mediated gene activation and imply that PKC-ε and MAP kinase may be involved in transducing this signal.

scholarly journals Transcriptional Activation of the Decidual/Trophoblast Prolactin-Related Protein Gene1

Endocrinology ◽  
1999 ◽  
Vol 140 (9) ◽  
pp. 4032-4039 ◽  
Author(s):  
Kyle E. Orwig ◽  
Michael J. Soares
Keyword(s):  
Transcriptional Activation ◽  
Promoter Activity ◽  
Mutational Analysis ◽  
Regulatory Element ◽  
Gene Activation ◽  
Cell Formation ◽  
Regulatory Elements ◽  
Related Protein ◽  
Trophoblast Cells ◽  
Decidual Cells

Abstract The decidual/trophoblast PRL-related protein (d/tPRP) is dually expressed by decidual and trophoblast cells during pregnancy. We have characterized the proximal d/tPRP promoter responsible for directing d/tPRP expression in decidual and trophoblast cells. We have demonstrated that the proximal 93 bp of d/tPRP 5′-flanking DNA are sufficient to direct luciferase gene expression in primary decidual and Rcho-1 trophoblast cells, but not in fibroblast, undifferentiated uterine stromal cells or trophoblast cells of a labyrinthine lineage. The 93-bp d/tPRP promoter was also sufficient to direct differentiation-dependent expression in trophoblast giant cells. Mutational analysis demonstrated the differential importance of activating protein-1 and Ets regulatory elements (located within the proximal 93 bp of d/tPRP 5′-flanking DNA) for activation of the d/tPRP promoter in decidual vs. trophoblast cells. Disruption of the activating protein-1 regulatory element inhibited d/tPRP promoter activity by more than 95% in decidual cells, and approximately 80% trophoblast cells. Disruption of the Ets regulatory element reduced d/tPRP promoter activity by approximately 50% in decidual cells, while inactivating the d/tPRP promoter in trophoblast cells. Protein interactions with the trophoblast Ets regulatory element were shown to be cell type specific and to change during trophoblast giant cell formation. In conclusion, a 93-bp region of the d/tPRP promoter is shown to contain regulatory elements sufficient for gene activation in decidual and trophoblast cells.

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