Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

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

The glycoprotein hormone alpha-subunit gene is expressed in a cell-specific manner in the anterior pituitary and placenta. Previous studies have shown that the region between -178 to -111 is indispensable for placental-specific expression of the human alpha-subunit gene. Using gene transfer techniques with chimeric luciferase plasmids, this report identifies regions of the mouse alpha-subunit promoter that are important for transcriptional activation in primary thyrotropic cells. Transient expression of a series of 5' flanking DNA deletions resulted in stepwise reductions of basal promoter activity between -480 to -417 (4-fold), -254 to -177 (5-fold), and -177 to -120 (3.5-fold). DNase-I protection analysis with nuclear extracts from thyrotropic tumor cells revealed specific protein-DNA interactions within each of these functionally defined regions. These were mapped to positions -474 to -452, -447 to -419, -213 to -170, and -158 to -101 within the 5' flanking region. In contrast, in mouse fibroblast L-cells no significant difference in alpha-subunit promoter activity was found by deleting the region from -480 to -177. However, a 3-fold decrease, similar to that found in primary thyrotropes, was found by deleting the region from -177 to -120. Further, a smaller region between -138 and -122 was the only area detected by the DNase-I protection assay using L-cell nuclear extracts. Thus, several cis-acting promoter elements located up-stream of position -177 are important for expression in thyrotropes. These elements also bind nuclear factors present in thyrotropes but not in nonpituitary fibroblasts and, therefore, differ from those mediating expression of the human alpha-subunit gene in the placenta.
Mol Endocrinol 1990 May
PMID:Identification of cis-acting promoter elements important for expression of the mouse glycoprotein hormone alpha-subunit gene in thyrotropes. 170 76

The sensitivity of the alpha-fetoprotein (AFP) gene to digestion by the enzyme DNaseI, and the presence of hypersensitive sites in the 5' region of this gene, were examined in hepatoma x fibroblast hybrid cells that exhibit extinction of AFP gene expression. Major changes occur in the extinguished gene, i.e., loss of long-range sensitivity to DNase digestion and of the hypersensitive sites. In this respect, the extinguished gene resembles the corresponding silent gene present in fibroblasts, but differs from the silent gene present in normal adult hepatocytes. These observations suggest that extinguisher factors acting on the AFP gene alter its conformation.
Somat Cell Mol Genet 1991 Jan
PMID:Major chromatin changes accompany extinction of alpha-fetoprotein gene in hepatoma x fibroblast hybrids. 170 63

The steroid-binding capacity of the adrenocortical pregnenolone-binding protein (PBP) is effectively destroyed by extreme temperature (boiling water for 2-5 min); however, the boiled preparation contains a factor that potentiates ligand binding when readded to native PBP. Treatment of the boiled fraction with calf intestinal alkaline phosphatase at pH 9 reverses the stimulatory effect on PBP activity. Additionally, if native PBP is first incubated with alkaline phosphatase, which converts it to a nonbinding form, activity can be fully restored in a dose-dependent manner by the addition of the boiled preparation. The factor (itself devoid of binding capacity) can also be generated by exposing native PBP to acidic conditions (pH 4). The molecule is small (mol wt, less than 2000), as judged by Sephadex G-25 gel filtration and equilibrium dialysis. It is not retained on Concanavalin-A-Sepharose and is not extractable with a variety of organic solvents. The factor remains active after lyophilization and has a net negative charge at pH 7.4 (determined by DEAE-cellulose chromatography). While the binding capacity of native PBP is destroyed by a variety of proteases, the heat-stable factor is unaffected by similar treatment. Additionally, factor activity is not susceptible to RNase, DNase, or lipase digestion. Thus, the protein moiety of the PBP has an absolute requirement for a distinct phosphorylated heat-stable factor for expression of ligand-binding activity, and it may be through this factor that binding activity is regulated. It is not yet known whether the factor is acting allosterically or actually functions as part of the steroid-binding site.
Mol Endocrinol 1991 Sep
PMID:Adrenocortical pregnenolone-binding protein activity requires a small heat-stable factor: evidence that regulation by phosphorylation/dephosphorylation occurs at the level of the factor, not the protein. 177 Sep 49

Vibrio cholerae is known to secrete DNase(s) into the extracellular environment. These proteins have been thought to be responsible for the difficulties in transforming this organism. In this work we demonstrate that the dns and xds genes differ and that their products are solely responsible for the extracellular DNase activity. By site-directed mutagenesis, strains have been constructed which are mutant in one or both genes. These strains have been assessed for their ability to be transformed with plasmid DNA and for their virulence in the infant mouse cholera model. DNase-deficient mutants can be readily transformed and the product of dns appears to be the more significant barrier. No effect on virulence was observed with the mutants.
Mol Microbiol 1991 Oct
PMID:Distinguishing between the extracellular DNases of Vibrio cholerae and development of a transformation system. 179 65

Expression of the vitellogenin genes in avian and amphibian liver is regulated by estrogens. The DNA elements mediating estrogen induction of the various vitellogenin genes of chicken and Xenopus encompass one or more copies of a 13-mer palindromic sequence called the estrogen-responsive element (ERE). Here we show that upon incubation with the purified estrogen receptor (ER) from calf uterus the Xenopus vitellogenin A2 gene yields a DNase-I footprint over the ERE between -331 and -319. This element does not mediate the response to glucocorticoids or progestins in T47D cells. The three guanine residues in each half of the palindrome are protected against methylation by dimethylsulfate after incubation with ER, but not with glucocorticoid (GR) or progesterone (PR) receptors. In contrast, the chicken vitellogenin II gene exhibits multihormonal regulation by estrogens, progestins, and glucocorticoids in T47D and MCF7 cells. Regulation is mediated by the DNA region between -721 and -591 that contains four binding sites for hormone receptors, as demonstrated by DNase-I footprints and methylation protection experiments. The two distal and most proximal binding sites are recognized by ER, GR, and PR, whereas the central binding site is only bound by ER and GR. At suboptimal concentrations, estrogens and progestins or glucocorticoids act synergistically. In experiments using a DNA fragment containing an ERE adjacent to a glucocorticoid-responsive element/progesterone-responsive element, ER and PR bind synergistically to their corresponding sites, perhaps explaining the functional synergism of both hormones. Thus, two very different regulatory elements are used to mediate estrogen induction of related genes in chickens and amphibians.
Mol Endocrinol 1991 Mar
PMID:Hormonal regulation of vitellogenin genes: an estrogen-responsive element in the Xenopus A2 gene and a multihormonal regulatory region in the chicken II gene. 189 Sep 89


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