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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The nature of a DNA element located in the -100 to -85 region of the rat PRL gene has been characterized. Previous studies demonstrated that this region may contribute to basal and hormonally regulated expression of the PRL gene. As this region contains a sequence with similarity to a consensus cAMP-responsive element (CRE), a possible role for the cAMP response element binding protein (CREB) has been explored. A point mutation which made the PRL CRE-like sequence less like a consensus CRE had little effect on basal or cAMP-stimulated expression of a PRL-luciferase reporter gene. DNase footprint studies demonstrated that the proximal region of the PRL gene does not contain a high affinity CREB binding site. Mobility shift experiments demonstrated that the major GH3 nuclear protein which interacts with the -100 to -85 region of the PRL gene in vitro is not CREB. Transfection of a dominant inhibitor of CREB action had little or no effect on expression of an indicator gene containing the PRL proximal region. Thus, the PRL proximal region does not contain a high affinity CREB binding site, and it is unlikely that CREB plays a major role in expression of the PRL gene. The functional capabilities of the -100 to -85 region of the PRL gene were then tested in a transfection assay. Synthetic multimers of this region were found to be sufficient to permit a transcriptional response to cAMP or TRH in GH3 cells and cAMP in Rat-1 cells.(ABSTRACT TRUNCATED AT 250 WORDS)
Mol Endocrinol 1992 Jun
PMID:Characterization of a non-tissue-specific, 3',5'-cyclic adenosine monophosphate-responsive element in the proximal region of the rat prolactin gene. 138 49

To identify cis-acting elements involved with the expression of the rat carboxypeptidase-E (CPE) gene, constructs containing various regions of the 5'-flanking region of the CPE gene attached to the luciferase reporter gene were transiently expressed in cell lines derived from pituitary (AtT-20 and GH4C1), liver (SK-HEP-1), and kidney (HEK293 and COS1). Regions of the CPE gene spanning the major transcription initiation site (-12 to 47) are sufficient for low levels of transcription. Activity is enhanced 3- to 15-fold by sequences present between -12 and -395 in all cell lines examined. Sequences between -395 and -3081 influenced transcription activity up to 5-fold in some, but not all, cell lines. There was no correlation between the transcription activities of the various constructs and the level of endogenous CPE mRNA in the cell lines, indicating that the tissue-specific elements responsible for the large variations in endogenous CPE mRNA levels are not present within -3081 to 47. The region between -395 and 45 was examined in greater detail using transient expression assays and DNase-I protection analysis. Transcription activity is enhanced in GH4C1 and HEK293 cells by sequence present between -12 and -84; this region contains a potential GC box, which binds factors present in GH4C1 nuclear extracts. Other regions between -340 and 80 that bind proteins in the GH4C1 nuclear extracts include the major transcription initiation site, which has homology to the initiator sequence; the pituitary-specific transcription initiation sites (-101 and -105); and sequences with homology to NF-1, Pan-1, simian virus-40 enhancer core, and AP-2-binding sites. Taken together, these results suggest that basal expression of the CPE gene from its major transcription initiation site, which does not contain an up-stream TATA box, is primarily under the control of an initiator-like element together with an upstream GC box.
Mol Endocrinol 1992 Dec
PMID:Expression of the rat carboxypeptidase-E gene in neuroendocrine and nonneuroendocrine cell lines. 149 89

Binding of nuclear proteins from wild oat aleurone protoplasts to the promoter regions of two gibberellin-regulated wheat alpha-amylase genes (alpha-Amy1/18 and alpha-Amy2/54) has been studied by gel retardation and DNase 1 footprinting. Gel retardation studies using 300-430 bp fragments of the promoters showed similar binding characteristics with nuclear extracts from both gibberellin A1-treated and untreated protoplasts. DNase 1 footprints localised binding of nuclear proteins from gibberellin A1-treated aleurone protoplasts to regions in both promoters. Similar sequence elements in the promoter regions of both genes were protected from digestion although the location and number of footprints in each promoter region were different. Each footprint contained either a sequence similar to the cAMP and/or phorbol ester response elements, or a hyphenated palindrome sequence. The presence of cAMP and/or phorbol ester response element-like sequences in the footprints suggests that transcription factors of the bZIP type may be involved in the expression of alpha-amylase genes in aleurone cells. Footprints containing hyphenated palindrome sequences, found in the promoter regions of both genes, suggest the possible involvement of other classes of transcription factor. The conserved alpha-amylase promoter sequence TAA-CAGA was also shown to bind nuclear protein in the alpha-Amy2/54 promoter. These observations are discussed in relation to alpha-amylase gene expression in aleurone and to functional data concerning these genes.
Plant Mol Biol 1992 Sep
PMID:Aleurone nuclear proteins bind to similar elements in the promoter regions of two gibberellin-regulated alpha-amylase genes. 151 Nov 35

Outer membrane protein P6 is an important antigen expressed on the surface of all strains of Haemophilus influenzae. The predicted amino acid sequence of P6 contains a region of alpha helices that shares sequence identity with a family of helix-turn-helix DNA-binding proteins. A search for sequence-specific binding sites that resemble an operator region within the gene revealed a sequence with striking homology to the consensus operator sequence for lambda Cro and repressor. To test the hypothesis that P6 binds its own gene, purified P6 on nitrocellulose was probed with plasmid DNA containing the P6 gene. P6 bound the P6 gene in this Southwestern blot assay. To further test the observation, gel shift analysis was performed. Gel shift assays using a P6-specific monoclonal antibody demonstrated that P6 in crude cell extracts binds to the region of the gene containing the putative binding site. Competition with a synthetic oligonucleotide corresponding to the putative binding site inhibited binding of P6 to the P6 gene on nitrocellulose and in the gel shift assay. In addition, this oligonucleotide bound directly to P6 on nitrocellulose. Finally, DNase footprinting confirmed that P6 bound specifically to the same region of the P6 gene. These results indicate that P6 binds to a sequence-specific site within its own gene, suggesting that P6 regulates its own expression. This represents the first example of a Gram-negative outer membrane protein binding to its own gene and has potentially important implications as a mechanism for regulation of expression of outer membrane antigens.
Mol Microbiol 1992 Feb
PMID:Outer membrane protein P6 of Haemophilus influenzae binds to its own gene. 156 Jul 83

The high affinity calcium-binding protein calbindin-D28K is one of the known proteins transcriptionally up-regulated by the hormonally active form of vitamin D3, 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3]. This regulation is tissue specific, since in the absence of 1,25-(OH)2D3, the expression of calbindin-D28K is virtually abolished in intestine, whereas it is decreased, but clearly detectable, in kidney, and it remains present at its highest level in cerebellum. Several studies have shown that there is a strong correlation between an increase in the sensitivity to nuclease digestion of a given gene locus and its potential for transcription. Furthermore, hypersensitive sites have often been mapped to regions of DNA including or surrounding sequences known to be important for the regulation of gene transcription. In this study we have scanned the 5'-end and flanking DNA of the calbindin-D28K gene for the presence of DNase-I-hypersensitive (DH) sites in order to localize possible regulatory regions involved in the tissue-specific and hormone-dependent regulation of this gene. We have found that in tissues where calbindin is not expressed, such as liver, no DH sites could be detected. In cerebellum, the same set of DH sites was observed in the presence or absence of 1,25-(OH)2D3 treatment, reflecting the vitamin D-independent expression of the calbindin gene in this tissue. A more complex pattern of DH sites was found in intestine, independently of the vitamin D status of the animal.(ABSTRACT TRUNCATED AT 250 WORDS)
Mol Endocrinol 1992 Mar
PMID:Local chromatin changes accompany the expression of the calbindin-D28K gene: tissue specificity and effect of vitamin D activation. 158 19

The proximal region of the rat PRL gene contains at least five transcription-stimulating elements that are located within a 170-basepair region up-stream of the TATA box. These cis-acting elements include four binding sites for the pituitary-specific transcription factor Pit-1 as well as another site for an unidentified factor. In this study interactions between different DNA elements have been examined through the construction of PRL-luciferase fusion genes containing mutations that disrupt various combinations of the individual DNA elements. In general, the disruption of multiple factor-binding sites had a much more than additive effect on expression of the luciferase constructs. Interestingly, comparison of the effects of disrupting pairs of binding sites demonstrated substantial differences in the effects of different combinations of mutations, suggesting that cooperative interactions may reflect specific interactions. Mutations that disrupted all five cis-elements of the PRL proximal region essentially abolished transcription from the proximal promoter. This finding suggests that there are no other DNA elements within the proximal 200 basepairs of the PRL gene that can independently stimulate transcription. Although there is strong functional cooperativity between different cis-elements in the PRL gene, DNase footprint studies failed to detect cooperative binding between different Pit-1 elements. Overall, the findings demonstrate that the normal transcription of the PRL gene involves strong cooperative interactions between individual DNA elements in the proximal region.
Mol Endocrinol 1992 Apr
PMID:Analysis of functional cooperativity between individual transcription-stimulating elements in the proximal region of the rat prolactin gene. 158 22

Exposure of mammalian cells to a variety of agents leads to the activation of pre-existing proteins and the induction of specific genes. We have recently described the appearance of a specific DNA-binding protein in nuclei from cells exposed to ionizing radiation (Singh, S. P., and Lavin, M. F. (1990) Mol. Cell. Biol. 10, 5279-5285). This protein is present in the cytoplasm of unperturbed cells and is apparently translocated to the nucleus in response to radiation damage. We describe here the purification and characterization of this specific DNA-binding protein. Purification involved the use of affinity chromatography employing a multimeric form of the DNA-binding motif conjugated to cyanogen bromide-activated Sepharose. Three DNA-binding species were recognized by UV-cross-linking and South-Western analysis. The major species or that with the highest affinity was approximately 70 kDa in size. DNase-1 footprint analysis revealed a single binding site in the kappa immunoglobulin gene enhancer and in a putative control sequence upstream from the c-myc gene. At salt concentrations as high as 1 M, up to 40% of the DNA-binding activity was maintained and the Kd was calculated to be 1.205 x 10(-6) M-1. Binding activity was found to be modulated by phosphorylation. Removal of phosphate groups from the protein resulted in a major loss of binding activity. It is not clear at this stage whether the factor(s) described here plays a role in transcription control or a more general DNA-processing role in response to radiation damage.
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PMID:Purification and characterization of a DNA-binding protein activated by ionizing radiation. 158 18

Human placenta contains the methyltrienolone binding protein (MTBP), an androgen binding protein which is distinct from the androgen receptor. This study demonstrates that the human choriocarcinoma cell line (JEG-3) also contains the MTBP and that in both human placenta and JEG-3 cells the MTBP is located exclusively in the nucleus and in particular is associated with DNase 1 resistant chromatin.
J Steroid Biochem Mol Biol 1992 May
PMID:The methyltrienolone binding protein of JEG-3 cells and human placenta is localized within the nucleus and is tightly associated with chromatin. 160 39

CG is encoded by separate alpha- and beta-subunit genes. Expression of both genes is stimulated by cAMP, but the kinetics of activation are different, with cAMP stimulation of the alpha gene preceding that of the beta gene. The cAMP response element (CRE) in the alpha gene contains a palindromic DNA sequence, TGACGTCA, that binds the transcription factor CREB, a nuclear phosphoprotein that is activated by protein kinase-A. Previously, detailed characterization of a CRE in the CG beta gene had been difficult due to low levels of expression in transfected cells. In this study the 5'-flanking sequence of the CG beta gene was fused to a sensitive luciferase (LUC) reporter gene, allowing delineation of a CG beta CRE in transient expression assays performed in JEG-3 choriocarcinoma cells. The full-length CG beta promoter, -3700 to 362 basepairs (bp), was stimulated 8- to 14-fold by treatment with 1 mM 8-bromo-cAMP. Analyses of a series of deletion mutants in the CG beta promoter demonstrated that -311 CG beta LUC retained nearly complete cAMP stimulation, but deletion to -187 bp eliminated cAMP responsiveness. Overlapping DNA fragments between -311 and -30 bp were fused to a heterologous promoter (-99 alpha LUC) to further define the locations of basal elements and CREs. Basal expression required a combination of at least two distinct elements between -311 and -30 bp, whereas cAMP responsiveness was conferred by sequences between -311 and -202 bp. Shorter DNA sequences within this region were insufficient for cAMP stimulation, suggesting that more than one element may be required. DNase-I footprinting and gel mobility shift studies demonstrated at least three distinct protein-binding sites within the CG beta CRE sequence. Recombinant CREB (expressed in E. coli) did not bind to these sites, and they share no sequence homology with the alpha gene CRE, indicating that a cAMP-responsive transcription factor other than CREB interacts with the CG beta promoter.
Mol Endocrinol 1991 May
PMID:Novel cyclic adenosine 3',5'-monophosphate response element in the human chorionic gonadotropin beta-subunit gene. 164 92

In isolated mouse nuclei the chromocenters were shown to be the pericentromeric heterochromatin regions (PCHR). After the decreasing of bivalent ion concentration (0.1 mM Ca2+, 2 mM Mg2+) the main and peripheral parts of the chromatin remained on the contrary as the compact chromatin bodies. The additional ultrasound treatment of isolated nuclei in the presence of 0.1 mM Ca2+ with DNAase II and triton X-100 resulted in the species enriched by the condensed PCHR.
Mol Biol (Mosk)
PMID:[Behavior of pericentromere heterochromatin regions under different conditions of chromosome decondensation in isolated nuclei]. 169 70


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