SEARCH · PubMed Health

Results for “regulatory element transcripts”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 91 records · Page 5Linked to original sources

PubMed1994

Identification of negative-acting and protein-binding elements in the mouse alpha A-crystallin -1556/-1165 region.

The mouse alpha A-crystallin-encoding gene (alpha A-cry) is expressed in a highly lens-preferred manner. To date, it has been shown that this lens-preferred expression is controlled by four proximal positive-acting transcriptional regulatory elements: DE1 (-111/-97), alpha A-CRYBP1 (-66/-57), PE1/TATA (-35/-19) and PE2 (+24/+43). The present study extends our knowledge of mouse alpha A-cry transcriptional regulatory elements to the far upstream region of that gene by demonstrating that the -1556 to -1165 region contains negative-acting sequence elements which function in transfected lens cells derived from mouse, rabbit and chicken. This is the first negative-acting regulatory region identified in mouse alpha A-cry. The -1556 to -1165 region contains sequences similar to repressor/silencer elements identified in other genes, including those highly expressed in the lens, such as the delta 1-crystallin (delta 1-cry) and vimentin (vim) genes. The -1480 to -1401 region specifically interacts with nuclear proteins isolated from the alpha TN4-1 mouse lens cell line. Contained within this protein-binding region and positioned at -1453 to -1444 is a sequence (RS1) similar to the chicken delta 1-cry intron 3 repressor, and which competes for the formation of -1480 to -1401 DNA-protein complexes. Our findings suggest that lens nuclear proteins bind to the mouse alpha A-cry RS1 region. We demonstrate that the chicken delta 1-cry intron repressor binds similar nuclear proteins in chicken embryonic lens cells and mouse alpha TN4-1 lens cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1994

A novel myogenic regulatory circuit controls slow/cardiac troponin C gene transcription in skeletal muscle.

The slow/cardiac troponin C (cTnC) gene is expressed in three distinct striated muscle lineages: cardiac myocytes, embryonic fast skeletal myotubes, and adult slow skeletal myocytes. We have reported previously that cTnC gene expression in cardiac muscle is regulated by a cardiac-specific promoter/enhancer located in the 5' flanking region of the gene (bp -124 to +1). In this report, we demonstrate that the cTnC gene contains a second distinct and independent transcriptional enhancer which is located in the first intron. This second enhancer is skeletal myotube specific and is developmentally up-regulated during the differentiation of myoblasts to myotubes. This enhancer contains three functionally important nuclear protein binding sites: a CACCC box, a MEF-2 binding site, and a previously undescribed nuclear protein binding site, designated MEF-3, which is also present in a large number of skeletal muscle-specific transcriptional enhancers. Unlike most skeletal muscle-specific transcriptional regulatory elements, the cTnC enhancer does not contain a consensus binding site (CANNTG) for the basic helix-loop-helix (bHLH) family of transcription factors and does not directly bind MyoD-E12 protein complexes. Despite these findings, the cTnC enhancer can be transactivated by overexpression of the myogenic bHLH proteins, MyoD and myogenin, in C3H10T1/2 (10T1/2) cells. Electrophoretic mobility shift assays demonstrated changes in the patterns of MEF-2, CACCC, and MEF-3 DNA binding activities following the conversion of 10T1/2 cells into myoblasts and myotubes by stable transfection with a MyoD expression vector. In particular, MEF-2 binding activity was up-regulated in 10T1/2 cells stably transfected with a MyoD expression vector only after these cells fused and differentiated into skeletal myotubes. Taken together, these results demonstrated that distinct lineage-specific transcriptional regulatory elements control the expression of a single myofibrillar protein gene in fast skeletal and cardiac muscle. In addition, they show that bHLH transcription factors can indirectly transactivate the expression of some muscle-specific genes.

Amino Acid Sequence↗

PubMed1991

Molecular cloning, structure, promoters and regulatory elements for transcription of the Bacillus licheniformis encoded regulon for xylose utilization.

In this article we describe the cloning of the xyl regulon encoding xylose utilization from Bacillus licheniformis by complementation of a xyl mutant of B. subtilis. The xylose isomerase encoding gene, xylA, was sequenced and identified by its extensive homology to other xylose isomerases. The expression of xylA is regulated on the level of transcription by a repressor protein encoded by xylR. Its gene has the opposite orientation of xylA and the start codons are 181 bp apart. A deletion of xylR renders xylA expression constitutive. The xylR sequence was determined and is discussed with respect to its homology to other xylR structures. Primer extension analyses of the xylA and xylR transcripts under repressing and including conditions define their promoters and confirm the regulation of xylA transcription. Furthermore, some induction of the xylR transcript by xylose is also observed. The regulatory sequence of both genes consists of a bipolar promoter system and contains three palindromic sequence elements. Their potential functions with respect to xylA and xylR regulation are discussed. The primary structures of the genes, promoters and regulatory sequences are compared to the xyl regulons encoded by B. subtilis, B. megaterium, Staphylococcus xylosus and E. coli. Homology is greatest between the B. subtilis and B. megaterium encoded xyl genes while the B. licheniformis borne genes are clearly more distant. The next greater differences are found to the S. xylosus and the greatest to the E. coli encoded genes. These results are discussed with respect to the taxonomic relations of these bacteria.

Aldose-Ketose Isomerases↗

PubMed1991

Functional analysis of cis- and trans-regulatory elements of the lactate dehydrogenase A subunit promoter by in vitro transcription.

Using a transcription system from nuclear extracts of rat C6 glioma cells we have investigated the mechanism by which transcription from the lactate dehydrogenase A subunit (LDH) promoter is regulated via the cAMP-activated pathway. We demonstrated that the system accurately initiates transcription from the LDH promoter. Analysis of the competitive effects of linker-scanning mutants showed that the wild-type LDH promoter exhibited the highest competitive effect and reduced the rate of basal transcription, whereas LDH promoter fragments with a mutated cAMP-responsive element had little competitive activity. Cyclic AMP and the catalytic subunit of cAMP-dependent protein kinase stimulated the rate of transcription from the wild-type promoter, an effect which was inhibited by the catalytic subunit inhibitor protein. A beta-galactosidase-cAMP-responsive element binding protein fusion protein had no effect on the basal rate of transcription. Addition of beta-galactosidase-cAMP-responsive element binding protein together with cAMP or the catalytic subunit, however, enhanced the rate of transcription. The demonstrated regulatory effects indicate that the sensitivity of the transcription system makes it suitable for the functional analysis of homologous LDH and possibly heterologous transcription regulatory elements.

Animals↗

PubMed1995

Cis-regulatory elements and transcription factors involved in the regulation of the transforming growth factor-beta 2 gene.

Embryonal carcinoma (EC) cells and embryonic stem (ES) cells provide useful model systems for studying differentiation during early mammalian development. Previous studies have demonstrated that differentiation of two restricted mouse EC cell lines is accompanied by activation of the TGF-beta 2 gene. Moreover, one negative and two positive regulatory regions upstream of the transcription start site were identified, which appear to play key roles in the transcriptional regulation of the human TGF-beta 2 gene. In this report, we demonstrate that the same three regulatory regions strongly influence the activity of the TGF-beta 2 promoter in differentiated cells derived from the multipotent human EC cell line, NT2/D1, and from the murine totipotent ES cell line, CCE. We also determined that the same three regions are active in the regulation of the TGF-beta 2 gene in the murine parietal endoderm-like cell line, PYS-2. However, an additional negative regulatory region appears to contribute to the regulation of the TGF-beta 2 gene in PYS-2 cells. Last, mutation of a CRE/ATF element located just upstream of the transcription start site of the TGF-beta 2 gene reduces significantly the activity of the TGF-beta 2 promoter in the differentiated cells. However, in contrast to our previous findings, our gel mobility shift analyses demonstrate that this CRE/ATF element is bound by similar proteins in nuclear extracts prepared from undifferentiated and differentiated mouse EC cells as well as from undifferentiated human EC cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1992

The insulin and islet amyloid polypeptide genes contain similar cell-specific promoter elements that bind identical beta-cell nuclear complexes.

The pancreatic beta cell makes several unique gene products, including insulin, islet amyloid polypeptide (IAPP), and beta-cell-specific glucokinase (beta GK). The functions of isolated portions of the insulin, IAPP, and beta GK promoters were studied by using transient expression and DNA binding assays. A short portion (-247 to -197 bp) of the rat insulin I gene, the FF minienhancer, contains three interacting transcriptional regulatory elements. The FF minienhancer binds at least two nuclear complexes with limited tissue distribution. Sequences similar to that of the FF minienhancer are present in the 5' flanking DNA of the human IAPP and rat beta GK genes and also the rat insulin II and mouse insulin I and II genes. Similar minienhancer constructs from the insulin and IAPP genes function as cell-specific transcriptional regulatory elements and compete for binding of the same nuclear factors, while the beta GK construct competes for protein binding but functions poorly as a minienhancer. These observations suggest that the patterns of expression of the beta-cell-specific genes result in part from sharing the same transcriptional regulators.

Amyloid↗

PubMed1992

Regulatory elements and transcriptional regulation by testosterone and retinoic acid of the rat nerve growth factor receptor promoter.

The low-affinity nerve growth factor receptor (LNGFR) is a membrane-associated glycoprotein which is thought to participate in some of the biological activities of nerve growth factor (NGF). Expression of the LNGFR gene is known to be regulated both during development and in response to various agents in cell culture. However, molecular mechanisms responsible for the regulation have not been described. We report here an analysis of a 4.8-kb sequence from the 5'-flanking region of the rat LNGFR gene. Several regulatory elements were identified in this region by transfection of plasmid constructs containing sequences from LNGFR fused to a bacterial cat reporter gene. The proximal part of the promoter region (0.4-kb) was shown to be sufficient to support cat expression in all cell types used. A silencer element located between -1.5 kb and -1.8 kb from the start of translation, as well as an enhancer element in more upstream regions of the promoter, were identified in the phaeochromocytoma cell line, PC12, and in the Sertoli cell line, TM4, that express the LNGFR gene. Treatment of TM4 cells with retinoic acid (RA) increases the level of LNGFR mRNA twofold, while testosterone treatment results in a tenfold decrease. Regions of the promoter responsive to testosterone and RA in TM4 cells were found at -610 to -860 bp and -1840 to -4800 bp upstream from the translation start codon, respectively. A RA-responsive element active in PC12 cells is located between bp -610 to -860 from the start codon.

Animals↗

PubMed1987

Expression of antibody cDNA in murine myeloma cells: possible involvement of additional regulatory elements in transcription of immunoglobulin genes.

Expression vectors for cDNA of the kappa and gamma 1 chains of a monoclonal antibody directed against creatine kinase were introduced into murine myeloma cells. Kappa and gamma 1 cDNA were either under the control of the SV40 early promoter or of the cognate promoters and enhancers of the light- and heavy-chain genes. Secretion of immuno-reactive kappa and gamma 1 chains into the culture medium was demonstrated with the SV40 promoter as well as with the cognate promoters. Expression of gamma 1 cDNA with the SV40 early promoter was about twice as high as with the heavy-chain promoter and enhancer. Expression of kappa cDNA under the control of the SV40 early promoter was about 17 times higher than with the light-chain promoter and enhancer. These expression levels were compared to those of a genomic immunoglobulin (Ig) kappa determinant, including introns. Such an entire kappa gene led to expression of the light chain at levels double those with the kappa cDNA construction using the SV40 promoter and about 35 times as high when using kappa cDNA and the cognate promoter and enhancer. This result might indicate that, besides the cognate promoter and enhancer elements, other intragenic elements are involved in the regulation of Ig expression. However, the SV40 early promoter seems to be able to compensate for the absence of these postulated regulatory elements probably located in the introns.

Animals↗

PubMed1990

Role of alpha-fetoprotein regulatory elements in transcriptional activation in transient heterokaryons.

The requirements for activation of the mouse alpha-fetoprotein (AFP) gene in transient heterokaryons were investigated. For this purpose, the 7-kilobases of DNA flanking the 5' end of the AFP gene were linked to a mouse major histocompatibility complex (MHC) class I structural gene. The fusion gene was stably integrated at different sites into mouse L-cells, which do not transcribe the AFP gene. Transient heterokaryon fusions demonstrated that the silent AFP-MHC gene and the endogenous AFP gene were activated by factors present in HepG2 cells, a liver-derived cell line, but not by those in HeLa cells. Activation was detected at the protein level in single heterokaryons by using monoclonal antibodies against the cell surface protein and at the mRNA level in populations of cells. The AFP promoter alone was sufficient for activation could be used for DNA transfer strategies to identify genes which can activate AFP promoter elements in trans.

Animals↗

PubMed1992

cis-acting elements that confer lung epithelial cell expression of the CC10 gene.

To define cis-acting genetic elements responsible for cell-specific transcriptional regulation of the CC10 gene, DNA sequences spanning nucleotides -2338 to +49 of the rat CC10 gene were linked to a reporter gene coding for chloramphenicol acetyltransferase (CAT). In transient expression assays, CC10 sequences were capable of restricting CAT expression to a human lung adenocarcinoma cell line similar to pulmonary Clara cells. Transgenic mice harboring the hybrid RtCC10-CAT construct expressed high levels of CAT activity specifically within protein extracts of lung and trachea. Transcripts for the CAT reporter gene colocalized with those for the endogenous murine CC10 gene within the airways of transgenic mice. Functional analysis of deletion mutants identified stimulatory, inhibitory, and cell type-specific transcriptional regulatory elements. The results of gel retention and DNaseI protection assays suggest that a transcriptional stimulatory region located between -320 and -175, and a cell type-specific regulatory element located between -175 and +49, result from a series of protein-DNA interactions occurring at -220 to -205 and -128 to -86, respectively. Lung epithelial specific transcriptional regulatory elements described herein will be useful for expression of chimeric genes within epithelial cells lining the trachea, bronchi, and bronchioles of mice.

Adenocarcinoma↗

PubMed1991

Molecular cloning, structure, promoters and regulatory elements for transcription of the Bacillus megaterium encoded regulon for xylose utilization.

The xylA and xylB genes of Bacillus subtilis BR151 encoding xylose isomerase and xylulokinase, respectively, were disrupted by gene replacement rendering the constructed mutant strain unable to grow on xylose as the sole carbon source. The Bacillus megaterium encoded xyl genes were cloned by complementation of this strain to xylose utilization. The nucleotide sequence of about 4 kbp of the insertion indicates the presence of the xylA and xylB genes on the complementing plasmid. Furthermore, a regulatory gene, xylR, is located upstream of xylA and has opposite polarity to it. The intergenic region between the divergently oriented reading frames of xylR and xylA contains palindromic sequences of 24 bp spaced by five central bp and 29 bp spaced by 11 bp, respectively, and two promoters with opposite orientation as determined by primer extension analysis. They overlap with one nucleotide of their--35 consensus boxes. Transcriptional fusions of lacZ to xylA, xylB and xylR were constructed and revealed that xylA and xylB are repressed in the absence and can be 200-fold induced in the presence of xylose. The increased level of xylAB mRNA in induced and its absence in repressed cells confirms that this regulation occurs on the level of transcription. Deletion of the xylR gene encoding the Xyl repressor results in constitutive expression of xylAB. The transcription of xylR is autoregulated and can be induced 9-fold by xylose. The mechanism of this regulation is not clear. While the apparent xyl operator palindrome is upstream of the xylR promoter, the potential recognition of another palindrome downstream of this promoter by Xyl repressor is discussed.

Aldose-Ketose Isomerases↗

PubMed1990

Cloning and expression of the human S100 beta gene.

S100 protein is a low molecular weight, EF-hand, Ca2(+)-binding protein widely distributed and conserved in the central nervous system of vertebrates. The gene coding for the beta subunit of human S100 protein (S100 beta) has been recently mapped to chromosome 21. In order to study the expression of this gene in normal and abnormal brain development, we have isolated and characterized overlapping genomic clones spanning the region coding for human S100 beta and its flanking sequences. The intron-exon organization of the human S100 beta gene is similar to that of the genes coding for several other members of the S100 protein subfamily of EF-hand proteins. The human S100 beta gene is composed of 3 exons, the first of which specifies the 5'-untranslated region, while the second and third each encode a single EF-hand, Ca2(+)-binding domain. The promoter region contains several potential regulatory transcription elements including the cAMP-responsive elements CRE and AP-2. A novel sequence motif, the S100 protein element, situated in close proximity to the TATA box of the genes of several members of the S100 protein subfamily, has been identified. In addition, multiple repeats with similar nucleotide sequence and location to the recently reported beta globin direct repeat elements have been also found in the human S100 beta promoter. A full length (17.3 kilobases) copy of the human S100 beta gene was constructed and transfected into rat glioma C6 cells. Stable transfectants were shown to express correctly initiated transcripts of the human S100 beta gene, indicating that the cloned sequences contain functional regulatory transcription elements.

Amino Acid Sequence↗

PubMed1989

Characterization of a single copy gene encoding ferredoxin I from pea.

We have isolated, mapped, and sequenced a genomic clone containing the ferredoxin I (Fed-1) gene from Pisum sativum. The gene is present as a single copy per haploid genome. It has no introns, and it specifies a 753-nucleotide transcript encoding a 149-amino acid protein including a 52-residue transit peptide. Upstream sequences from Fed-1 contain several elements with similarity to transcriptional regulatory elements from RbcS and Cab genes, and gel mobility shift assays show that nuclear extracts from light-grown pea leaves contain one or more DNA binding activities specific for Fed-1 5'-flanking sequences. RbcS and Cab regulatory sequences are only weak competitors for this binding, however, and the RbcS and Cab similarities mostly lie outside of the region essential for binding. These data are discussed in terms of previously observed physiological differences between the light responses of Fed-1 and other genes.

Amino Acid Sequence↗

PubMed1991

Regulatory sequences of duck hepatitis B virus C gene transcription.

The regulatory elements involved in transcription of the C gene of duck hepatitis B virus (DHBV) were investigated. Several DHBV DNA fragments were assayed for C gene promoter, enhancer, and silencer activity by using a chloramphenicol acetyltransferase (CAT) reporter gene and transfection of established liver and nonliver cell lines. A major transcript initiating at nucleotide positions 2532 and 2533 and three minor transcripts initiating at positions 2453/2454 and 2461 were identified in cells containing these constructs. These positions correspond to the 5' end of the C mRNA and were close to that of the pre-C mRNAs, respectively, found in infected livers. The pre-C mRNAs were only detected when sequences located between the initiation sites of the pre-C and C mRNAs were deleted. These sequences downregulated, in an orientation-independent fashion, a heterologous promoter and were found to contain a consensus motif common to negative transcriptional regulatory elements previously characterized in other cellular and viral genes. C gene promoter activity was only observed in highly differentiated liver cells and was dependent on a short DHBV DNA fragment containing an enhancer core consensus motif. These data indicate that transcription of the DHBV C gene is regulated by positive, negative, and differentiation factor-responsive elements.

Animals↗

PubMed1992

Transcriptional regulation during T-cell development: the alpha TCR gene as a molecular model.

The regulation of gene expression during lymphocyte differentiation is a complex process involving interactions between multiple positive and negative transcriptional regulatory elements. In this article, transcriptional regulation of the archetypal T-cell-specific gene, alpha TCR, is discussed. Major recent developments, including the identification of novel families of transcription factors that regulate multiple T-cell genes during thymocyte ontogeny and T-cell activation, are described.

Base Sequence↗

PubMed1987

Properties of a distal regulatory element controlling transcription of the U2 small nuclear RNA.

The upstream region of human U2 genes contains a distal transcriptional control element, previously mapped between nucleotide (nt) positions -198 and -258 (Westin et al., 1984b). In the present study we show that it resembles transcriptional enhancers in being active even from a distance of 1.4 kb. However, in contrast to most other enhancers it functions unidirectionally in Xenopus laevis oocytes. The distal control element was further mapped by construction of truncated templates for U2 RNA transcription. The results showed that templates, which extended to either of nt positions -214 and -218, were inactive. Templates comprising sequences to nt positions -225 or -226 displayed an intermediate level of activity whereas templates which extend to nt -258 were fully active. It has previously been shown that the human U2 enhancer contains binding sites for the so-called octamer binding protein and for transcription factor Sp1 [Janson et al., Nucl. Acids Res. 15 (1987) 4997-5016]. The partially active templates included one binding site for the octamer binding protein, whereas the fully active template included, in addition, two Sp1 binding sites, thus indicating that these transcription factors are of importance for U2 RNA transcription. The structure of the enhancer was also probed by inserting a pair of complementary synthetic oligodeoxynucleotides which represented the region between nt positions -235 and -215 into a truncated template which lacked the enhancer. The oligodeoxynucleotide enhanced transcription to approximately 50% of the level obtained with templates extending to position -258.

Animals↗

PubMed1986

Cellular promoters incorporated into the adenovirus genome: effects of viral regulatory elements on transcription rates and cell specificity of albumin and beta-globin promoters.

In the accompanying paper (Friedman et al., Mol. Cell. Biol. 6:3791-3797, 1986), hepatoma-specific expression of the rat albumin promoter within the adenovirus genome was demonstrated. However, the rate of transcription was very low compared with that of the endogenous chromosomal albumin gene. Here we show that in hepatoma cells the adenovirus E1A enhancer, especially in the presence of E1A protein, greatly stimulates transcription from the albumin promoter but not the mouse beta-globin promoter. This enhancer-dependent stimulation did not occur in myeloma cells in which a virus containing a immunoglobulin promoter and enhancer did function. These experiments suggest a limited distribution in cultured differentiated cells of cell-specific transcription factors. However, either the regulation of such cell-specific factors breaks down in other cultured cells, or strictly cell-specific factors are not at play in controlling cell-specific transcription, because HeLa cells could transcribe the albumin promoter from the same start site about 10% as well as hepatomas could and 293 cells could transcribe both albumin and globin promoters.

Adenovirus Early Proteins↗

PubMed1989

Pancreatic beta-cell-type-specific expression of the rat insulin II gene is controlled by positive and negative cellular transcriptional elements.

The insulin gene is expressed almost exclusively in pancreatic beta-cells. The DNA sequences that control cell-specific expression are located upstream of the transcription initiation site. To identify the cis-acting transcriptional control regions within the rat insulin II gene that are responsible for this tissue-specific expression pattern, we constructed a series of 5'-flanking deletion mutants and analyzed their expression in vivo in transfected insulin-producing and -nonproducing cell lines. Pancreatic beta-cell-specific expression was shown to be controlled by enhancer sequences lying between nucleotides -342 and -91 relative to the transcription start site. The rat insulin II enhancer appears to be a chimera, composed of a number of distinct cis-acting DNA elements. Both positive and negative transcriptional regulatory elements appear to be responsible for this cell-type-specific expression. We have shown that expression from one element within the enhancer, which is found between nucleotides -100 and -91, is regulated by both positive- and negative-acting cellular transcription factors. Expression from chimeras containing only the enhancer element sequences from -100 to -91 were active only in insulin-producing cells, indicating that the positive-acting factor(s) required for this activity may be active only in beta-cells. In contrast to the enhancer region, the rat insulin II gene promoter did not appear to require cell-specific transcription factors. Promoter mutants with 5'-flanking sequences extending to nucleotides -90 and -73 were constitutively active in both insulin-producing and -nonproducing cells. These results suggest that rat insulin II gene transcription in pancreatic beta-cells is imparted by a combination of both negative- and positive-acting cellular factors interacting with the gene enhancer.

Animals↗