Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| the nxsm recombinant inbred strains of mice: genetic profile for 58 loci including the mtv proviral loci. | we report the construction of 17 recombinant inbred (ri) strains of mice derived from the progenitor strains nzb/binre and sm/j and the typing of this ri strain set, designated nxsm, for 58 loci distributed on 16 autosomes and the x chromosome. two backcrosses involving nzb/binj and sm/j were constructed to confirm chromosomal assignments and determine gene orders suggested from nxsm ri strain data. from these results we recommend that chromosomal assignments and gene orders suggested from analy ... | 1990 | 2165966 |
| functional elements of the steroid hormone-responsive promoter of mouse mammary tumor virus. | transcription from the promoter of mouse mammary tumor virus is subject to induction by several classes of steroid hormones as well as to repression by a negative regulatory element present in the long terminal repeats of proviral dna. in order to characterize the functional elements of the promoter that in some way must respond to these regulatory signals, a number of promoter mutations were constructed, including a set of linker-scanning mutations across the entire promoter region. analysis of ... | 1990 | 2166825 |
| segregation patterns of endogenous mouse mammary tumor viruses in five recombinant inbred strain sets. | we identified mouse mammary tumor proviral loci in the akr/j, c3h/hej, c57bl/6j, c57l/j, dba/2j, and swr/j inbred mouse strains and determined their segregation patterns in the akxd, akxl, bxd, bxh, and swxl recombinant inbred strain sets. two new mtv loci, mtv-29 and mtv-30, were identified. mtv-30 was genetically mapped to chromosome 12. additionally, two previously identified mtv loci, mtv-14 and mtv-23, were genetically mapped to chromosome 4 and chromosome 6, respectively. | 1990 | 2166832 |
| mouse mammary tumor virus (mmtv) infection in swiss and riii mice. correlation between resistance to exogenous infection and anti-mmtv serum response. | host-virus relationships were examined in mice from the two mouse mammary tumor virus (mmtv)-infected strains swiss mb+ and riii, which harbour the same mmtv variant, and from the derived sublines swiss mb- and riiif, which were freed of milk-borne mmtv by foster-nursing. these two strains are not phylogenetically related, the swiss strain bearing the endogenous mtv-3 locus in its dna. in riii and swiss mb+ mice, the incidence of early mammary tumors, which was of 96% and 8%, respectively, was c ... | 1990 | 2167058 |
| transcription stimulates homologous recombination in mammalian cells. | transcription stimulates homologous recombination in saccharomyces cerevisiae and has been implicated in the control of recombinational events during the development of mammalian immune systems. here, we describe a plasmid-based system in which an inducible promoter from the mouse mammary tumor virus is located upstream of heteroallelic neomycin genes carried on two plasmids. pairs of plasmids are introduced into chinese hamster ovary cells by electroporation, and recombination is monitored by s ... | 1990 | 2167441 |
| the dose dependence of glucocorticoid-inducible gene expression results from changes in the number of transcriptionally active templates. | glucocorticoid hormones induce the transcription of genes having glucocorticoid response elements in a dose dependent manner. to determine whether this dose dependence represents a response of individual templates or of the mass of templates, we introduced a bacterial beta-galactosidase gene linked to the glucocorticoid-inducible enhancer/promoter of the mouse mammary tumor virus (mtv) into ltk- cells and obtained stable transformants containing a single or a few templates per cell. visual inspe ... | 1990 | 2167833 |
| distribution of mouse mammary tumor virus-related sequences does not correlate with the taxonomic position of their hosts. | sequences (mrs) distantly related to mouse mammary tumor virus (mmtv) were found in genomes of a wide range of mammalian species using blot hybridization. the number of mrs copies and the degree of their homology with the hybridization probe varied and did not correlate with the taxonomic position of the species. nevertheless, within a genus the set of mrs was species specific and reflected the taxonomic relation between the species. mrs were also found in avian genomes and the degree of their h ... | 1990 | 2168108 |
| influence of mammary cell differentiation on the expression of proteins encoded by endogenous balb/c mouse mammary tumor virus genes. | the interactions between differentiation-associated cellular events in the intact mammary gland or in cultured mammary cells and the post-transcriptional activity of the endogenous mouse mammary tumor virus (mmtv) loci were investigated. the transcriptional activities of the endogenous mmtv proviruses of the balb/c mouse strain (mtv-6, mtv-8 and mtv-9) appear to be regulated differentially during pregnancy-induced mammary gland development (j.e. knepper, d. medina and j.s. butel, j. virol. 59, 5 ... | 1990 | 2168113 |
| role of chromatin structure in transcriptional regulation of mmtv ltr hormone-dependent promoter. | studies of chromatin structure were performed in mouse fibroblast cell lines containing bovine papilloma virus (bpv) based artificial minichromosomes containing mouse mammary tumor virus (mmtv) long terminal repeat (ltr), a retroviral promoter regulated by glucocorticoids, driving the transcription of v-ha-ras. these minichromosomes fractionate with the "active chromatin", indicating an association of the minichromosomes with components of the "nuclear matrix". two regions of the minichromosomes ... | 1990 | 2168572 |
| cyclic amp and calcium in mouse mammary tumour virus expression: effects and post-transcriptional site of action. | the role of cyclic amp (camp), calcium, calmodulin and protein kinase c (pkc) in the expression of both mouse mammary tumour virus (mmtv) rna and an mmtv glycoprotein, gp58, was investigated in normal mammary epithelium in culture. none of these second messengers had any effect on mmtv rna. dibutyryl camp alone had no effect on gp58 levels but, at low concentrations (0.05-0.1 mm), it nearly doubled the induction seen with insulin, cortisol and prolactin; higher concentrations were inhibitory. al ... | 1990 | 2168707 |
| affinity of interactions between human glucocorticoid receptors and dna: at physiologic ionic strength, stable binding occurs only with dnas containing partially symmetric glucocorticoid response elements. | sucrose density gradient shift assays were adapted to permit determination of the affinity of interaction between human glucocorticoid receptors (gr) and dna under conditions of dna excess. saturation analyses were performed to ascertain dissociation constants for the interaction of activated human gr with each of five dna fragments. centrifugation of gr-dna complexes on sucrose gradients under nearly isotonic salt conditions revealed similar affinities with dissociation constants in the range o ... | 1990 | 2168738 |
| establishment of ddd/1-mtv-2/mtv-2, nu/nu and ddd/1-mtv-2/mtv-2, nu/+ mice: preliminary characterization in relation to mtv antigen expression and mammary tumorigenesis. | to investigate the effects of the t-cell deprivation on viral mammary tumorigenesis, two double congenic mouse strains of the ddd genetic background, ddd/1-mtv-2/mtv-2, nu/nu and ddd/1-mtv-2/mtv-2, nu/+, were produced by the cross between ddd/1-mtv-2/mtv-2 (ddd-mtv-2) and ddd/1-nu/nu mice, followed by repeated intercross breedings. expression of the mouse mammary tumor virus (mtv)-gp52 antigen was demonstrated in the mammary glands of mice from 14 days on, in both -nu/nu and -nu/+ females. mamma ... | 1990 | 2168807 |
| thyroid hormone requirement for retinoic acid induction of mouse mammary tumor virus expression. | in normal mouse mammary epithelium, insulin, cortisol, and prolactin are absolute requirements for mouse mammary tumor virus expression. retinoic acid further increased mouse mammary tumor virus expression two- to threefold but only when triiodothyronine was also present; neither retinoic acid nor triiodothyronine alone had any effect. | 1990 | 2168995 |
| contacts between steroid hormone receptors and thymines in dna: an interference method. | understanding the mechanisms by which regulatory proteins recognize genetic information stored in dna relies on the availability of methods to analyze their interaction with individual nucleotides and their reactive groups. here we describe the use of kmno4 to analyze the contacts between steroid hormone receptors and thymines within a hormone responsive element. although several pyrimidine residues are highly conserved among different receptor binding sites their participation in sequence recog ... | 1990 | 2169621 |
| mechanism and biological significance of the ha-ras-induced activation of the na+/h(+)-antiporter. | expression of the transforming ha-ras oncogene in mmtv-ltr transfected nih 3t3 cells leads to a growth factor independent activation of the na+/h(+)-antiporter. the activation of the antiporter is insensitive to the protein kinase inhibitor staurosporine and equally expressed in protein kinase c-depleted cells. it is concluded that the ha-ras induced activation of the antiporter occurs by a protein kinase c-independent mechanism. an inhibition of the na+/h(+)-antiporter by dimethylamiloride or a ... | 1990 | 2169700 |
| constitutive expression of the c-fos protooncogene in murine keratinocytes: potentiation of the mitogenic response to insulin-like growth factor 1. | in order to determine the biological effects of activation of the c-fos protooncogene on growth and differentiation of balb/mk mouse keratinocytes, these cells were transfected with the plasmid pman-fos, which encompasses the human c-fos coding region under transcriptional control of a mouse mammary tumor virus promoter, as well as the gene encoding neomycin phosphotransferase. of approximately 70 individual clones obtained by selection in geneticin, 5 clones that constitutively expressed c-fos ... | 1990 | 2170007 |
| recombinant human glucocorticoid receptor induces transcription of hormone response genes in vitro. | a recombinant full length human glucocorticoid receptor stimulates transcription in vitro of test genes containing synthetic glucocorticoid and progesterone response elements or murine mammary tumor virus promoter. the receptor expressed in a baculoviral vector is highly active, enhancing transcription of hormone response genes greater than 30-fold even at a receptor concentration of 1.2 nm. the enhancement of transcription is glucocorticoid and progesterone response element-dependent, suggestin ... | 1990 | 2170364 |
| quantitative analysis of the glucocorticoid receptor-dna interaction at the mouse mammary tumor virus glucocorticoid response element. | purified glucocorticoid receptor (gr) from rat liver was used for a quantitative analysis of the protein-dna interaction at specific gr-binding segments within the 5'-long terminal repeat of the mouse mammary tumor virus. a truncated receptor was generated and used to demonstrate formation of heterodimeric gr, which furthermore was shown to be in rapid equilibrium with receptor-monomer. the relative affinity for gr binding to specific gr sites versus random calf thymus dna was approximately 2 x ... | 1990 | 2170368 |
| oestrogen enhances the responsiveness of the mmtv-ltr to glucocorticoid in zr-75-1 human breast cancer cells. | treatment of zr-75-1 human breast cancer cells with oestrogen has no direct effect on the expression of a transfected mmtv-ltr but enhances its inducibility in response to glucocorticoid treatment. this effect which can be produced with both oestradiol and diethylstilbestrol is specific to induction of the mmtv-ltr, no effect of the treatment on expression driven by the rsv-ltr being observed. the effect can be observed in cells pre-treated with oestrogen prior to removal of dna and glucocortico ... | 1990 | 2170763 |
| virus envelope-based peptide vaccines against virus-induced mammary tumors. | previous studies by us and others established that mammary tumors induced by murine mammary tumor virus (mumtv) could be prevented to various extents by prior vaccination with mumtv-containing or subviral component immunogens. in this report, four predicted surface-accessible peptide regions (ep-1 to ep-4) of the major viral envelope glycoprotein (gp52) of c3h-mumtv were tested as carrier-conjugated vaccines for the protection of balb/c mice against a live virus challenge. with tumor incidence a ... | 1990 | 2171218 |
| the interaction of a c-jun/fos related protein factor with the u3 sequences of the mouse mammary tumor virus ltr. | using polyacrylamide gel mobility shift assay we have detected a nuclear factor (nf-s) in a mouse mammary tumor cell line (gr) that binds to an upstream sequence domain (-766 to -737) near the 5'-end of the mouse mammary tumor virus (mmtv) long terminal repeat (ltr). antibodies to the products of the jun and fos oncogenes interfered with the binding potential of this factor, indicating that the factor shares antigenic determinants with c-jun/ap-1. in vitro translated c-jun and c-fos were also fo ... | 1990 | 2171522 |
| binding of the glucocorticoid receptor induces a topological change in plasmids containing the hormone-responsive element of mouse mammary tumor virus. | glucocorticoid hormones stimulate transcription of the mouse mammary tumor virus (mmtv) promoter by means of an interaction of the hormone receptor with a set of upstream dna-binding sites called the hormone-responsive element (hre). in an attempt to understand the underlying molecular mechanism, we have analyzed the influence of receptor binding on the topological state of plasmids carrying different parts of the hre. incubation of negatively supercoiled plasmids containing the intact hre with ... | 1990 | 2171552 |
| the processed pseudogene of mouse thymidine kinase is active after transfection. | aside of the gene coding for cytoplasmic thymidine kinase, the genome of mouse cells carries two pseudogenes. both are inactive in situ. one of the pseudogenes is a processed pseudogene in which a two base pair deletion caused a shift of the reading frame and a shortening of the gene product from the 233 amino acids of thymidine kinase to 177 amino acids in the pseudogene product. we report here that introduction of this pseudogene into ltk- cells gave rise to cells with a thymidine kinase posit ... | 1990 | 2171983 |
| effects of energy restriction on mouse mammary tumor virus mrna levels in mammary glands and uterus and on uterine endometrial hyperplasia and pituitary histology in c3h/shn f1 mice. | we investigated the effects of energy restriction on the pituitary-ovarian axis and on a hormone responsive gene, the mouse mammary tumor virus (mmtv). female c3h/shn f1-hybrid mice, known to display a high incidence of mammary tumors, ate an energy-restricted diet (48 kcal/wk) or a control diet (95 kcal/wk) beginning at the time of weaning. by 67 wk of age, 12 of 32 mice in the control group, but none of the 33 mice in the energy-restricted group, had developed mammary tumors. six tumor-free mi ... | 1990 | 2172493 |
| prolactin and glucocorticoid hormones control transcription of the beta-casein gene by kinetically distinct mechanisms. | transcription of the beta-casein milk protein gene in the hc11 mouse mammary epithelial cell line is induced synergistically by the hormones glucocorticoid and prl. sequential treatment of hc11 cells with glucocorticoid and prl demonstrated that the two hormones had different modes of action on beta-casein transcription. pretreatment with dexamethasone enhanced the response to subsequent induction by prl, but not vice versa. dexamethasone increased the sensitivity of the cells to respond to prl. ... | 1990 | 2172795 |
| expression of recombinant androgen receptor in cultured mammalian cells. | full-length rat and human androgen receptor (ar) cdna clones were expressed in cos-7 and cv1 monkey kidney cells to analyze the ar protein using immunological and cotransfection techniques. the studies were aided by the development of two rabbit polyclonal antibodies, designated ar32 and ar52, directed against epitopes within the n-terminal region of ar. each antibody recognizes native ar by sucrose gradient analysis and detects a 114-kilodalton protein in cos cells transfected with human or rat ... | 1990 | 2172802 |
| genetic diversity of spontaneously developed primary and metastatic mammary tumor cells in mice. | metastatic cells are often considered to be clonal derivatives of one of the primary tumor cell subpopulations. to determine if the cells of spontaneously developed lung nodules in a mammary tumor-bearing mouse represent the major or minor population of the cells in the primary tumor, comparisons were made of the pattern of their mouse mammary tumor virus (mmtv) proviral integrations, and their insertional mutations of the mouse mammary tumor proto-oncogenes, int-1 and int-2. of the 78 tumor-bea ... | 1990 | 2173623 |
| [comparison of background factors relevant to mammary tumorigenesis between ddd/1-mtv-2/mtv-2 congenic and ddd/1 mice]. | to elucidate the possible participation of the mtv-2 gene in the background factors relevant to mammary tumorigenesis, ddd/1-miv-2/mtv-2 (ddd-mtv-2) congenic and ddd/1 background mice were compared for endocrine and immune organs, mammary gland development, expression of mouse mammary tumor virus (mmtv)-gp 52 antigen, hyperplastic alveolar nodules (han) and mammary tumor incidence. the congenic strain had been established by introducing mtv-2 from grs/ajms (gr) into ddd/1 mice by repeated 12 bac ... | 1990 | 2173665 |
| naf, a trans-regulating negative-acting factor encoded within the mouse mammary tumor virus open reading frame region. | the mouse mammary tumor virus (mmtv) long terminal repeat (ltr) open reading frame (orf) encodes a negative acting factor (naf). in our test system, naf mediates its effect in trans on another mmtv provirus in which the 5' ltr has been replaced by that of rous sarcoma virus. naf effects are evidenced at the level of transcriptional initiation rather than as reduced mrna stability. the introduction of a premature termination codon into the mmtv ltr-encoded orf abolishes the transcriptional down r ... | 1990 | 2173798 |
| breast cancer sequences identified by mouse mammary tumor virus (mmtv) antiserum are unrelated to mmtv. | 1990 | 2174415 | |
| high expression of ras p21 correlates with increased rate of abnormal mitosis in nih3t3 cells. | the modulation of responsive genes by hormonal stimulation is an attractive in vitro model system for the study of a wide variety of biological processes. using this methodology we have investigated the effect of the human oncogene protein p21ras on mitosis using mouse mammary tumor virus long terminal repeat (mmtv-ltr)-directed gene expression. following the induction of p21 protein, abnormal mitotic figures were scored in metaphase and anaphase. elevated expression of p21 was associated with m ... | 1990 | 2174524 |
| tumorigenesis and male sterility in transgenic mice expressing a mmtv/n-ras oncogene. | transgenic mice carrying the activated n-ras oncogene under the transcriptional control of the mouse mammary tumor virus (mmtv) long terminal repeat were produced. the transgene is expressed in a tissue distribution consistent with the fact that it is driven by the mmtv-ltr, and similarly to mmtv/h-ras constructs, its presence elicits tumors in harderian, mammary and salivary glands. in addition it appears to compromise male reproductive function, which has not been described with the other ras ... | 1990 | 2174525 |
| role of the int-genes in murine mammary tumor development and implications for human breast cancer. | 1990 | 2175298 | |
| dna rotational positioning in a regulatory nucleosome is determined by base sequence. an algorithm to model the preferred superhelix. | mmtv-ltr sequences -190/-45 position a histone octamer both in vivo and in vitro. experimental evidence suggested that nucleosome rotational positioning is determined by the dna sequence itself. we developed an algorithm that is able to predict the most favorable path of a given dna sequence over a histone octamer, based on rotational preferences of different dinucleotides. our analysis shows that these preferences are sufficient for explaining the observed rotational positioning of the mmtv-ltr ... | 1990 | 2175885 |
| tissue-specific factors and glucocorticoid receptors present in nuclear extracts bind next to each other in the promoter region of mouse mammary tumor virus. | nuclear extracts from different mouse tissues have been used to study the interaction of factors with the steroid-inducible promoter of mouse mammary tumor virus. in addition to the glucocorticoid receptor that interacts with the distal region of the promoter, several tissue-specific proteins were found to bind to the 5' flanking region of the receptor-binding site and to the basal promoter region. the differences in the pattern of protection observed suggest that tissue-specific factors might c ... | 1990 | 2176241 |
| structural features of a regulatory nucleosome. | dna sequences from the long terminal repeat of the mouse mammary tumor virus (mmtv-ltr) position nucleosomes both in vivo and in vitro. here, were present chromatin reconstitution experiments showing that mmtv-ltr sequences from -236 to +204 accommodate two histone octamers in positions compatible with the in vivo data. this positioning is not influenced by the length of the dna fragment and occurs in linear as well as in closed circular dna molecules. mmtv-ltr dna sequences show an intrinsic be ... | 1990 | 2176242 |
| characterization of oligosaccharide chains on mouse mammary tumor virus envelope proteins and the implications for the mechanism of their glucocorticoid regulated processing. | glucocorticoid hormone is required for complete posttranslational processing of the glycosylated mouse mammary tumor virus envelope precursor, pr74env in the murine t-lymphosarcoma cell line, w7mg1. metabolic labeling studies with [35s]methionine, [3h]galactose, and [3h]mannose, combined with enzymatic digestion analyses with a variety of endoglycosidases, demonstrated that both proteolytic processing and n-linked oligosaccharide maturation depended, either directly or indirectly, on glucocortic ... | 1990 | 2177143 |
| potentiation of oncogenic n-ras-induced neurite outgrowth and ornithine decarboxylase activity by phorbol dibutyrate and protein kinase inhibitor h-8. | a recombinant n-ras oncogene, under the transcriptional control of a corticosteroid-inducible mouse mammary tumor virus (mmtv) promoter, has been stably transfected into a pc12 rat pheochromocytoma subline. this cell line, designated ur61, undergoes n-ras-induced neurite outgrowth and cessation of division when treated with dexamethasone (guerrero et al.: biochemical and biophysical research communications 150:1185-1192, 1988). we have employed the ur61 cell line as a model for ras oncogene-indu ... | 1990 | 2180965 |
| stable expression of mouse cyp1a1 and human cyp1a2 cdnas transfected into mouse hepatoma cells lacking detectable p450 enzyme activity. | using the mouse hepatoma hepa-1c1c7 c37 mutant cell line that exhibits negligible benzo[a]pyrene hydroxylase (cyp1a1) and acetanilide 4-hydroxylase (cyp1a2) enzyme activities, we developed stable transfectants of plasmids containing the murine cyp1a1 (cytochrome p(1)450) and the human cyp1a2 (p(3)450) cdnas. we show that the assay measuring metabolism of ethoxyfluorescein ethyl ester (efee) was invaluable in screening large numbers of individual cell lines for high cyp1a1 enzyme activity. nine d ... | 1990 | 2206399 |
| functional characterizations of the androgen receptor confirm that the molecular basis of androgen action is transcriptional regulation. | in an effort to understand the molecular basis of androgen action in the prostate, we isolated androgen receptor (ar) cdna from rat ventral prostate cells and analyzed the transcriptional regulatory activity of the encoded protein in a cotransfection assay. we found that ar is capable of inducing chloramphenicol acetyltransferase activity more than 20-fold using the mouse mammary tumor virus ltr as a source of androgen response elements. this induction was observed in both monkey cv1 cells and h ... | 1990 | 2274054 |
| definition of the human androgen receptor gene structure permits the identification of mutations that cause androgen resistance: premature termination of the receptor protein at amino acid residue 588 causes complete androgen resistance. | we have isolated and characterized the gene encoding the human androgen receptor. the coding sequence is divided into eight coding exons and spans a minimum of 54 kilobases. the positions of the exon boundaries are highly conserved when compared to the location of the exon boundaries of the chicken progesterone and human estrogen receptor genes. definition of the intron/exon boundaries has permitted the synthesis of specific oligonucleotides for use in the amplification of segments of the androg ... | 1990 | 2293020 |
| calorie consumption level influences development of c3h/ou breast adenocarcinoma with indifference to calorie source. | to analyze simultaneously the influence attributable to calorie consumption level and percentage of dietary fat on the spontaneous development of mammary adenocarcinoma, virgin female c3h/ou mice were separated into five dietary groups. four groups of mice were fed purified diets either ad libitum (16-18 kcal/mouse/day) or restricted 40% in calorie consumption (10-11 kcal/mouse/day), and diets contained either 4.5%, 7.5%, 67%, or 68% calories from fat. mice that consumed isocaloric diets develop ... | 1990 | 2294519 |
| differentiation-dependent expression of provirus-activated int-1 oncogene in clonal cell lines derived from a mouse mammary tumor. | the int-1 mammary oncogene is frequently activated by proviral insertion in mouse mammary tumors. to characterize the target cell for the oncogenic action of int-1, we have isolated permanent cell lines with distinct morphologies and differentiation characteristics, starting from a tumor with a rearranged int-1 gene. polygonal cells had retained many differentiation markers of epithelial cells and produced adenocarcinomas upon transplantation in syngenic mice. sphere-forming-cuboidal cells are p ... | 1990 | 2326076 |
| two distinct estrogen-regulated promoters generate transcripts encoding the two functionally different human progesterone receptor forms a and b. | the human progesterone receptor (hpr) cdna, synthesized from t47d breast cancer cells, and the hpr gene 5'-flanking region were cloned and sequenced. comparison of the cdna-deduced amino acid sequence with other pr homologues demonstrated the modular structure characteristic of nuclear receptors. as in the case of the chicken homologue, there are two hpr forms, a and b, which originate from translational initiation at aug2 (codon 165) and aug1, respectively. northern blot analysis of t47d mrna u ... | 1990 | 2328727 |
| glucocorticoid-dependent maturation of mouse mammary tumor virus glycoproteins in mouse lymphoma cells: isolation of variants with constitutive viral protein maturation and normal glucocorticoid receptor function. | the posttranslational maturation and cell surface localization of mouse mammary tumor virus (mmtv) envelope glycoproteins is regulated by glucocorticoid hormone in mouse t-lymphoma cell line w7mg1. only when the cells are cultured with glucocorticoid is the mmtv envelope precursor, pr74, converted efficiently to the two mature proteolytic products, gp52 and gp33. by immunological selection we have isolated protein-processing variants that express the mature viral proteins constitutively on the c ... | 1990 | 2330009 |
| a single base mutation in the androgen receptor gene causes androgen insensitivity in the testicular feminized rat. | the complete form of androgen insensitivity is an inherited x-linked syndrome in which genetic males fail to undergo masculinization in utero due to defective functioning of the androgen receptor (ar). the molecular basis of androgen insensitivity was investigated in the testicular feminized (tfm) rat with this syndrome. ar mrna size and amount, as well as nuclear ar protein revealed by immunocytochemistry, suggested normal expression of the ar gene in the tfm rat. sequence analysis of the ar co ... | 1990 | 2341409 |
| specific region in hormone binding domain is essential for hormone binding and trans-activation by human androgen receptor. | complementary dna (cdna) clones encoding human-androgen receptors (har) were isolated using synthetic oligonucleotides homologous to the human glucocorticoid, estradiol, progesterone, and aldosterone receptors as probes to screen a human testis lambda gt11 cdna library. one of the receptor proteins (hara) produced in vitro bound the [3h]dehydrotestosterone ([3h]dht) with high affinity and selectivity similar to the human androgen receptor present in target tissues and cells. a second cdna clone ... | 1990 | 2342476 |
| isolation of a genomic sublibrary enriched for glucocorticoid-regulated genes. | glucocorticoids regulate gene expression by causing the glucocorticoid receptor to bind to an enhancer-like dna element termed the glucocorticoid regulatory element (gre). the resultant effect on transcription of specific genes causes a cascade of intracellular events that determines the growth or differentiated function of the target tissue. although virtually all animal tissues respond to glucocorticoids, it has proven difficult to elucidate the molecular events which underlie physiologically ... | 1990 | 2344394 |
| biosynthesis of peptide precursors and protease inhibitors using new constitutive and inducible eukaryotic expression vectors. | a series of expression vectors has been constructed as based on the pml derivative of pbr322. the eukaryotic transcription units employ various promoters followed by polycloning sites for 3-9 commonly used restriction enzymes and are completed by the sv40 polyadenylation sequence. in 4 of the vectors, designed for co-transfection or transient expression studies, only a single transcription unit containing either a constitutive or an inducible promoter was incorporated. the human ubiquitin (ubc) ... | 1990 | 2379587 |
| cooperativity and specificity in the interactions between dna and the glucocorticoid receptor dna-binding domain. | we have employed fluorescence spectroscopy to study the chemical equilibrium between a 115 amino acid protein fragment containing the dna-binding domain of the human glucocorticoid receptor (dbdr) and a 24-base-pair dna oligomer containing the glucocorticoid response element (gre) from the mouse mammary tumor virus promoter region and compared it with the binding to nonspecific dna at various ionic conditions. we find that binding to both dnas is cooperative but that dbdr shows a higher affinity ... | 1990 | 2383551 |
| transcriptional activation and nuclear targeting signals of the human androgen receptor. | the androgen receptor (ar) is a signal-transducing protein required for sexual differentiation, development, and expression of the male phenotype. a series of human ar deletion mutants were created either by site-directed mutagenesis using restriction enzyme digestion, the polymerase chain reaction, or, for a series of unidirectional nh2-terminal deletions, exonuclease iii digestion. receptor mutants were expressed in monkey kidney cos cells as truncated ar proteins between 20 and 107 kda as rev ... | 1991 | 1985913 |
| long terminal repeats of dwarf hamster endogenous retrovirus are highly diverged and do not maintain efficient transcription. | recently we described a new endogenous proretrovirus of dwarf hamster phodopus sungorus (mrs-ps). its sequence possesses evident homology with the endonuclease domain of the mouse mammary tumor virus pol gene. here we present nucleotide sequence data on three clones of retroviral long terminal repeats. as many as 15% of substituted, deleted, and inserted base pairs were found while comparing these sequences. hence, mrs-ps seems to be rather an old genetic element which originated about 30 millio ... | 1991 | 1994585 |
| interaction of androgen response elements with the dna-binding domain of the rat androgen receptor expressed in escherichia coli. | a fragment of the rat androgen receptor (amino acids 533-637) containing the dna-binding domain was produced in escherichia coli as a fusion product with protein a of staphylococcus aureus. the fusion protein was purified on igg-sepharose, a method that does not involve the use of denaturing agents. approximately 4 mg of fusion protein was obtained from 500 ml of bacterial culture. in gel shift assays, the recombinant dna-binding domain displays an affinity for a fragment of the long terminal re ... | 1991 | 1995608 |
| decreased glucocorticoid receptor activity following glucocorticoid receptor antisense rna gene fragment transfection. | depression is often characterized by increased cortisol secretion caused by hyperactivity of the hypothalamic-pituitary-adrenal axis and by nonsuppression of cortisol secretion following dexamethasone administration. this hyperactivity of the hypothalamic-pituitary-adrenal axis could result from a reduced glucocorticoid receptor (gr) activity in neurons involved in its control. to investigate the effect of reduced neuronal gr levels, we have blocked cellular gr mrna processing and/or translation ... | 1991 | 1996114 |
| synergism between steroid response and promoter elements during cell-free transcription. | we have analyzed quantitatively the influence of distal promoter elements on steroid-responsive gene expression in vitro. functional synergism between enhancer and distal promoter elements was examined using two model promoters, one containing a natural promoter (mouse mammary tumor virus long terminal repeat) and one constructed artificially. human glucocorticoid receptor (gr) expressed in baculovirus induces transcription from a mouse mammary tumor virus long terminal repeat-containing dna tem ... | 1991 | 2005127 |
| lovastatin selectively inhibits ras activation of the 12-o-tetradecanoylphorbol-13-acetate response element in mammalian cells. | to evaluate ras-mediated signal transduction, an alkaline phosphatase gene (seap) was placed under the control of the ras-inducible phorbol ester response element (tre) in murine fibroblasts (tre-seap cells). the kirsten ras gene was placed under the control of the glucocorticoid-inducible mouse mammary tumor virus promoter and introduced into the tre-seap cells. dexamethasone increased ras expression in the tre-seap cells carrying the kirsten ras gene and stimulated seap activity 25-fold. lavos ... | 1991 | 2005914 |
| transcriptional control by nuclear receptors. | gene regulation by steroid hormones is accomplished by a variety of different mechanisms leading to induction or repression of particular genes. these mechanisms are all mediated by a single class of intracellular hormone receptors, which in the unliganded state are maintained in an inactive form by association with other cellular proteins, including hsp90. induction of the mouse mammary tumor virus (mmtv) requires binding of the hormone receptor to a hormone-responsive element (hre) that is pre ... | 1991 | 2010057 |
| polyomavirus middle tumor antigen increases responsiveness to growth factors. | the middle tumor antigen (mt) of polyomavirus is unable to transform a clone of nih 3t3 cells to anchorage independence (l. raptis and j.b. bolen, j. virol. 63:753-758, 1989). however, this oncogene increased the responsiveness of these cells to the growth factors (alpha-like and beta-type transforming growth factors) produced by cells possessing the whole transforming region of polyomavirus. this resulted in the growth of nih 3t3 cells, expressing mt under control of the dexamethasone-regulatab ... | 1991 | 2016775 |
| identification of two distinct nuclear factors with dna binding activity within the glucocorticoid regulatory region of the rat alpha-1-acid glycoprotein promoter. | efficient glucocorticoid induction of alpha-1-acid glycoprotein (agp) mrna in rat hepatoma cells htc (jz-1) requires the activity of one or more preexisting and labile proteins acting cooperatively with the glucocorticoid receptor. inhibiting protein synthesis markedly diminishes the glucocorticoid induction of rat agp mrna without affecting the inducibility of other glucocorticoid inducible genes such as the mouse mammary tumor virus (mmtv) or tyrosine amino transferase (tat). the sequences res ... | 1991 | 2039514 |
| a frame-shift mutation in the androgen receptor gene causes complete androgen insensitivity in the testicular-feminized mouse. | the testicular feminized (tfm) mouse lacks completely androgen responsiveness; and therefore, is unique for studying the role of androgenic steroids in different biological processes. in order to understand the molecular basis of this mutation, 2.8 kilobases of cdna encoding the tfm mouse androgen receptor (ar) were amplified with a polymerase chain reaction (pcr) technique. no large deletion in the coding region of the tfm mouse ar was detected. however, sequence analysis revealed a single base ... | 1991 | 2041777 |
| inhibition of hiv-ltr gene expression by oligonucleotides targeted to the tar element. | all human immunodeficiency virus mrnas contain a sequence known as tar (trans-activating responsive sequence). the tar element forms a stable rna stem-loop structure which binds the hiv tat (trans-activator) protein and mediates increased viral gene expression. in principle, molecules which bind to the tar rna structure would inhibit trans-activation by perturbing the native rna secondary structure. we have constructed a series of phosphodiester and phosphorothioate antisense oligonucleotides wh ... | 1991 | 2062653 |
| concerted stimulation of transcription by glucocorticoid receptors and basal transcription factors: limited transcriptional synergism suggests mediation by coactivators/adaptors. | steroid receptors have been reported to stimulate transcription in a manner synergistic with other transcription factors. we have examined this synergism or functional cooperativity between glucocorticoid receptors and basal transcription factors in a variety of promoter and reporter gene contexts. a fragment containing a hormone response element from mouse mammary tumor virus was fused to well characterized promoters from the herpes virus thymidine kinase and mouse beta-globin genes and to rela ... | 1991 | 2072921 |
| characterization of int-5, a locus associated with early events in mammary carcinogenesis. | three chemically-induced precancerous mammary hyperplasias, independently isolated in balb/c mice, all contained mouse mammary tumor virus (mmtv) proviral dna integrated into a common region in chromosomal dna, designated int-5 (formerly int-h, gray et al., 1986). this site was cloned from a hyperplastic outgrowth (d2) into lambda phage. a 1.7 kb hind iii dna fragment, which flanks the 5' end of the mmtv insert, was generated from the cloned int-5 region. this fragment was used as probe (ih-2) t ... | 1991 | 1705320 |
| a superantigen encoded in the open reading frame of the 3' long terminal repeat of mouse mammary tumour virus. | mice express a collection of superantigens, which bind to class ii major histocompatibility proteins and interact with t cells bearing particular v beta chains as part of their alpha beta receptors. these superantigens have been suggested to be encoded by exogenous or endogenous mouse mammary tumour viruses. one such superantigen is now shown to be encoded in the open reading frame of the long terminal repeat of a mammary tumour virus, a gene of previously unknown function. | 1991 | 1706480 |
| two regions of the mouse mammary tumor virus long terminal repeat regulate the activity of its promoter in mammary cell lines. | in vivo expression of the mouse mammary tumor virus (mmtv) is restricted to a few organs, with the highest rate of transcription found in the mammary gland. using a series of mammary and nonmammary murine cell lines, we have identified two regulatory elements, located upstream of the hormone responsive element, that specifically regulate the mmtv promoter. the first element displays an enhancerlike activity and is coincident with the binding of a nuclear factor (designated mp4; position -1078 to ... | 1991 | 1708094 |
| a new approach combining interferon and bromocriptine la to prevent spontaneous mouse mammary carcinoma. | the development of spontaneous mammary carcinoma in c3h mice is mainly attributed to an oncogenic virus (mmtv) and the high prolactin levels of this inbred strain. interferon (ifn) reduces the incidence of mammary carcinoma in virgin c3h mice when administered during lactation. bromocriptine la, an antiprolactin drug, also decreases the incidence of this tumor in c3h mice. the combined action of mouse ifn-alpha + beta and bromocriptine la had a significant anticarcinogenic effect more significan ... | 1991 | 1709419 |
| a novel bk virus-based episomal vector for expression of foreign genes in mammalian cells. | a composite mammalian cell-e. coli shuttle vector was developed based on the human papova virus bk and psv-neo. the vector contains a dioxin-responsive enhancer (dre) controlling a mouse mammary tumor virus (mmtv) promoter for the inducible expression of inserted genes. in human cells the vector replicates episomally, presumably utilizing the bkv rather than the sv40 origin, and expresses the bk t/t antigens. a deletion in the late bk region precludes the expression of the core/capsid proteins v ... | 1991 | 1709496 |
| suppression of adenovirus type 5 e1a-mediated transformation and expression of the transformed phenotype by caffeic acid phenethyl ester (cape). | viral transformation and dna-transfection assays were employed to investigate the differential toxic effect of caffeic acid phenethyl ester (cape), an extract of the honeybee hive product propolis, on adenovirus type 5 (ad5)-transformed cloned rat embryo fibroblast (cref) cells. cape inhibited, in a dose-dependent manner, both de novo and carcinogen-enhanced transformation of cref cells by h5hr1, the cold-sensitive (cs) host-range mutant of ad5. cape had a selective inhibitory effect on ad5-indu ... | 1991 | 1712205 |
| host genetic background effect on the frequency of mouse mammary tumor virus-induced rearrangements of the int-1 and int-2 loci in mouse mammary tumors. | the frequency with which int-1 and int-2 are rearranged in mouse mammary tumors by mouse mammary tumor virus (mmtv)-induced insertional mutagenesis is a consequence of the host genetic background. in 75% of c3h mammary tumors, int-1 is rearranged by mmtv insertion, whereas only 30% of balb/cfc3h tumors contain a virus-induced rearrangement of int-1. this difference is significant (p less than 0.005) and could not be accounted for by the potentially additive effect of the genetically transmitted ... | 1991 | 1712864 |
| glucocorticoid induction of the adipocyte clone 5 gene requires high cell density. | we have previously reported the identification of a glucocorticoid and cell-density inducible gene (clone 5) that appears to play a regulatory role in adipocyte differentiation. in the current studies we have more carefully investigated the interplay between cell growth or differentiation and the glucocorticoid responsiveness of clone 5 rna. we find that inducibility by steroid hormone is independent of the differentiated state but surprisingly, occurs only when cells are at high cell density. i ... | 1991 | 1712909 |
| myoepitheliomas in inbred laboratory mice. | myoepitheliomas are subcutaneous tumors that arise from myoepithelial cells of various exocrine glands. in a retrospective study of 142 tumors observed over a period of 3 years, myoepitheliomas occurred spontaneously in a/hej, a/j, balb/cj, balb/cbyj, llc.a/ckc, and nod/lt inbred strains of mice. tumors presented primarily in the subcutaneous tissues of the ventral neck (74% of the myoepitheliomas evaluated) but were observed in several other subcutaneous locations, including the head, perineum, ... | 1991 | 1719689 |
| ras oncogenes amplify lymphokine (interleukin 3, granulocyte-macrophage colony-stimulating factor) induction by calcium ionophore. | interleukin 3 (il-3) expression in pb-3c mastocytes is transiently induced in vitro by treatment with the drug a23187, a calcium ionophore, or constitutively following ras-dependent transformation in vivo. while the mechanism of oncogenically induced il-3 expression is not clear, a23187-mediated lymphokine mrna accumulation is primarily the result of calcium-dependent mrna stabilization. we investigated whether the expression of various ras alleles influenced il-3 and granulocyte-macrophage colo ... | 1991 | 1722572 |
| [on the mechanisms of retardation of aging and inhibition of mammary tumorigenesis by energy restriction in shn/c3h f1 female mice]. | although it has long been known that energy restriction (er) inhibits tumors and retards aging in rats and mice, its mode of action remains unknown. in rodents, er alters the rate of age-related changes in physiological indices. thus, it affects a broad array of age-sensitive parameters. however, present evidence does not indicate which parameters are primary contributors to the deceleration of aging. compared to fasting or short-term underfeeding, little is known about the metabolic effects of ... | 1991 | 1749105 |
| mixed inocula of mouse mammary tumour cell subpopulations result in changes of organ-specific metastasis. | tumour and metastatic phenotypes, the pattern of mouse mammary tumour virus (mmtv) integration and expression, and the expression of a metastasis associated gene, nm23, were examined in three mammary tumour cell subpopulations, 66, 168 and 4526. tumour growth, host survival, metastatic aggressiveness, and the distribution of different cell types in metastasis resulting from mixed cell inocula were also analysed. the results of these studies indicated that the cell lines were distinguishable from ... | 1991 | 1752081 |
| a heterologous hormone response element enhances expression of rat beta-casein promoter-driven chloramphenicol acetyltransferase fusion genes in the mammary gland of transgenic mice. | previous studies have demonstrated that the entire rat beta-casein (r beta c) gene and a -524/+490 r beta c fragment-chloramphenicol acetyltransferase (cat) fusion gene are expressed preferentially in the mammary gland of transgenic mice in a developmentally regulated fashion. however, transgene expression was infrequent, less than 1% of that observed for the endogenous gene, and varied as much as 500-fold, presumably due to the site of chromosomal integration. to determine whether a heterologou ... | 1991 | 1775134 |
| expression of a human monoclonal anti-hiv-1 antibody in cho cells. | the cdna coding for the light and heavy chains, respectively, of the human monoclonal antibody 3d6 (igg1, kappa), which binds specifically to human immunodeficiency virus-1 (hiv-1) gp41, was inserted into three different mammalian expression vectors and transfected into chinese hamster ovary (cho) cells. transcription was under the control of rous sarcoma virus long terminal repeat (rsv ltr), human cytomegalovirus major immediate early (cmv ie) promoter, and mouse mammary tumor virus long termin ... | 1991 | 1809191 |
| transcriptional activation by tr3 receptor, a member of the steroid receptor superfamily. | tr3 receptor is a human homolog of mouse nurr77 and n10 protein and the rat ngfi-b protein. a cdna encoding a chimeric nuclear receptor composed of the n-terminal domain and c-terminal putative ligand-binding domain of the orphan receptor tr3 receptor and the dna-binding domain of the androgen receptor was constructed. the chimeric receptor, called tr3/ar/tr3 receptor, when expressed in cos-1 monkey kidney cells or pc-3 human prostate tumor cells, cotransfected with an are-containing mouse mamma ... | 1991 | 1843211 |
| determinants of retrovirus gene expression in embryonal carcinoma cells. | the expression of moloney murine leukemia virus is restricted in embryonal carcinoma (ec) cells. to characterize specific mutations necessary for expression of retroviruses in ec cells, we analyzed the expression of retrovirus mutants and recombinants thereof in ec cell lines f9 and pcc4. dna sequence comparison and functional studies allowed us to define three point mutations in the enhancer region of the viral mutants at positions -345, -326, and -166 and two point mutations within the 5'-untr ... | 1991 | 1845898 |
| identification of a novel mammary cell line-specific enhancer element in the long terminal repeat of mouse mammary tumor virus, which interacts with its hormone-responsive element. | we analyzed the long terminal repeat (ltr) of mouse mammary tumor virus for sequences that influence its promoter activity by using the chloramphenicol acetyltransferase assay. a series of ltr deletion mutants and recombinants between ltr and simian virus 40 regulatory sequences were used for these studies. through transfection experiments in three different human cell lines (t47d, mcf-7, and hela), we identified a novel mammary cell line-specific enhancer element on a 98-bp banii fragment (from ... | 1991 | 1845907 |
| a new nomenclature for int-1 and related genes: the wnt gene family. | 1991 | 1846319 | |
| transcription factor access is mediated by accurately positioned nucleosomes on the mouse mammary tumor virus promoter. | a fragment of the mouse mammary tumor virus (mmtv) promoter was reconstituted from pure histones into a dinucleosome with uniquely positioned octamer cores. core boundaries for the in vitro-assembled dinucleosome corresponded to the observed in vivo phasing pattern for long terminal repeat nucleosomes a and b. nuclear factor 1 (nf1), a constituent of the mmtv transcription initiation complex, was excluded from the assembled dinucleosome, whereas the glucocorticoid receptor was able to bind. duri ... | 1991 | 1846670 |
| alpha b crystallin accumulation is a specific response to ha-ras and v-mos oncogene expression in mouse nih 3t3 fibroblasts. | the conditional expression of the v-mos and ha-ras(ej) oncogenes in nih 3t3 cells leads to the accumulation of a 23-kda protein (p23) (r. klemenz, s. hoffmann, r. jaggi, and a.-k. werenskiold, oncogene 4:799-803, 1989). we purified p23 to homogeneity and determined part of the amino acid sequence. the obtained sequence is identical with that of the eye lens protein alpha b crystallin. northern (rna) blot and western immunoblot experiments were performed to demonstrate that alpha b crystallin mrn ... | 1991 | 1846673 |
| ubiquitous transcription factor otf-1 mediates induction of the mmtv promoter through synergistic interaction with hormone receptors. | steroid hormones induce transcription from the mouse mammary tumor virus (mmtv) promoter by complex mechanisms requiring binding of the hormone receptors to the hormone responsive element (hre) of the long terminal repeat region. here we show that the mmtv promoter contains two degenerated octamer motifs immediately upstream of the tata box that together bind otf-1 (oct-1, nfiii) with an affinity similar to the octamer consensus. in transfection experiments, mutation of these octamer motifs inte ... | 1991 | 1846780 |
| a maternally inherited superantigen encoded by a mammary tumour virus. | a collection of superantigens, molecules which in combination with class ii major histocompatibility complex (mhc) engage t cells bearing particular v beta chains as part of their alpha beta receptors, have recently been described. the mouse self superantigen, mls-1a, for example, in conjunction with many mhc class ii proteins, engages mouse t cells bearing v beta 6, 7, 8.1 and 9, almost regardless of the sequences of the other variable components of the receptors on the t cells. two types of su ... | 1991 | 1846947 |
| linkage of mls genes to endogenous mammary tumour viruses of inbred mice. | t cells that recognize self antigen are clonally deleted in the thymus--a maturation process that occurs in the context of histocompatibility molecules and the t-cell receptor. the minor lymphocyte stimulation antigens (mls) effect these deletions through interactions with the v beta portion of the t-cell receptor, thus mimicking bacterial 'superantigens'. intrigued by the fact that each known mls gene maps to the same chromosomal region as an endogenous mouse mammary tumour virus (mtv), we reev ... | 1991 | 1846948 |
| an endogenous retrovirus mediating deletion of alpha beta t cells? | a special class of self-antigens (endogenous superantigens) is capable of deleting many murine t cells on the basis of their expression of particular t-cell receptor v beta gene segments. in mice that endogenously express these antigens, tolerance is mediated in part by the clonal deletion of the relevant v beta-bearing t cells. the deletion of i-e-reactive v beta 5.2-bearing t cells is dependent on the coexpression of an i-e tolerogenic coligand (etc)14 and the gene for one of these coligands, ... | 1991 | 1846949 |
| genes encoding ligands for deletion of v beta 11 t cells cosegregate with mammary tumour virus genomes. | the t-cell receptor (tcr) repertoire is selected in the thymus after rearrangement of genes encoding tcr alpha and beta chains. selection is based on the recognition by newly emergent t cells of self-ligands associated with molecules of the major histocompatibility complex: some combinations result in positive selection, others in negative selection. negative selection, or clonal deletion, is an important mechanism for eliminating autoreactive t cells. a group of self-ligands involved in clonal ... | 1991 | 1846950 |
| binary system for regulating transgene expression in mice: targeting int-2 gene expression with yeast gal4/uas control elements. | we have developed a binary transgenic system that activates an otherwise silent transgene in the progeny of a simple genetic cross. the system consists of two types of transgenic mouse strains, targets and transactivators. a target strain bears a transgene controlled by yeast regulatory sequences (uas) that respond only to the yeast transcriptional activator gal4. a transactivator strain expresses an active gal4 gene that can be driven by any selected promoter. the current paradigm uses the muri ... | 1991 | 1846961 |
| expression of endogenous mtv provirus transcripts in balb/c splenic lymphocytes. | the presence of antigen(s) related to the exogenous milk-transmitted murine mammary tumor virus on the surface of balb/c splenic lymphocytes has been documented previously. since the balb/c strain lacks murine mammary tumor virus, the presence of murine mammary tumor virus-related antigen(s) on lymphocytes has been ascribed to expression of germinally transmitted mtv transcripts and proviruses were characterized to evaluate this hypothesis. transcripts from genomic size mtv provirus(es) accumula ... | 1991 | 1847745 |
| mos-induced inhibition of glucocorticoid receptor function is mediated by fos. | activation of glucocorticoid hormone-dependent transcription involves the binding of the glucocorticoid hormone to its receptor followed by a specific interaction of the hormone/receptor complex with glucocorticoid responsive elements in the promoter region of hormone-inducible genes. in stably transfected nih3t3 cells expressing the oncogene product of v-mos or fos, the expression from two glucocorticoid responsive promoters, mmtv ltr and metallothionein iia (mtiia), was shown to be impaired an ... | 1991 | 1847998 |
| localization and induced expression of fusion genes in the rat lung. | liposome-mediated gene transfer is useful for dna transfection into cells in culture. we wondered whether this method could be used to introduce new dna into the intact lung. fusion genes containing either the rous sarcoma virus (rsv) promoter or the mouse mammary tumor virus (mmtv) promoter (which contains glucocorticoid response elements) were linked to the bacterial gene chloramphenicol acetyltransferase (cat), an enzyme not present in mammalian cells. plasmids containing the rsv-cat fusion g ... | 1991 | 1848084 |
| clonal deletion of v beta 14-bearing t cells in mice transgenic for mammary tumour virus. | autoreactive t lymphocytes are clonally deleted during maturation in the thymus. deletion of t cells expressing particular receptor v beta elements is controlled by poorly defined autosomal dominant genes. a gene has now been identified by expression of transgenes in mice which causes deletion of v beta 14+ t cells. the gene lies in the open reading frame of the long terminal repeat of the mouse mammary tumour virus. | 1991 | 1848685 |
| incomplete proviral genome of mouse mammary tumour virus is present on chromosome y of nih swiss and some genetically related mouse strains. | an incomplete proviral genome of endogenous mammary tumour virus (mmtv) was found in dna of several strains of mice. this mmtv-related sequence was assigned to the y chromosome since it was clearly observed in male mice only. this mmtv provirus contained a sequence related to ltr (long terminal repeat), but not to gag-pol and env genes. nfs, nih swiss/s, sts/a, and dd/tbr mice have this sequence but balb/chea, shn, sln, c57bl/6njcl, c3h/henjcl and cba/jjcl mice are negative. in the strains conta ... | 1991 | 1849209 |
| histone hyperacetylation does not alter the positioning or stability of phased nucleosomes on the mouse mammary tumor virus long terminal repeat. | activation of mouse mammary tumor virus transcription by the hormone-bound glucocorticoid receptor results in disruption of a nucleosome that is specifically positioned on the promoter. limited treatment of cells with the histone deacetylase inhibitor sodium butyrate prevents receptor-dependent promoter activation and nucleosome disruption [bresnick, e. h., john, s., berard, d. s., lefebvre, p., & hager, g. l. (1990) proc. natl. acad. sci. u.s.a. 87, 3977-3981]. on the basis of this observation, ... | 1991 | 1849427 |
| cooperation between structural elements in hormono-regulated transcription from the mouse mammary tumor virus promoter. | the mouse mammary tumor virus (mmtv) promoter is under the control of several types of regulatory agents. the proximal promoter within the long terminal repeat (ltr), from -200 to the cap site and its regulation by steroid hormones have been extensively studied. however the precise role of sequences located upstream of this region remain unclear. we have constructed mmtv ltr deletion mutants coupled to the luciferase reporter gene and assayed their activities after transient transfection into tr ... | 1991 | 1851294 |
| androgen resistance associated with a mutation of the androgen receptor at amino acid 772 (arg----cys) results from a combination of decreased messenger ribonucleic acid levels and impairment of receptor function. | analysis of the nucleotide sequence of the coding segment of the androgen receptor gene in a patient (n105) with the receptor-negative form of complete testicular feminization has revealed a single substitution (cgc----tgc) at nucleotide 2476. this alteration results in the conversion of an arginine at amino acid 772 to a cysteine. introduction of this mutation into an androgen receptor cdna and transfection of the mutant cdna into cos cells result in the production of a receptor protein with an ... | 1991 | 1856263 |
| neither the endogenous nor a functional steroid hormone receptor binding site transactivate the ribosomal rna gene promoter in vitro. | the mammalian ribosomal rna gene promoters exhibit a conserved sequence between positions +1 and +16 that shows a high degree of homology to the response element for glucocorticoids and progestins (gre/pre). these sequences bind specifically the glucocorticoid receptor and the progesterone receptor (pr) albeit with lower affinity than a canonical gre/pre. because steroid hormones are known to affect expression of the ribosomal genes, we tested the influence of hormone receptors on the activity o ... | 1991 | 1911432 |
| glucocorticoid growth suppression response in 13762nf adenocarcinoma-derived con8 rat mammary tumor cells is mediated by dominant trans-acting factors. | the in vitro and in vivo growth of con8 cells, a single cell-derived subclone of the 13762nf-transplantable rat mammary adenocarcinoma, is strongly suppressed by glucocorticoid hormones. hybrids were formed between glucocorticoid-suppressible con8.hd6 mammary tumor cells (con8 transfected with the histidinol dehydrogenase selectable marker) and either glucocorticoid-resistant 8ruv7 mammary tumor cells (derived from con8) or mct-htc rat hepatoma cells. both of the glucocorticoid-resistant 8ruv7 a ... | 1991 | 1933866 |
| evaluation of the role of ligand and thermal activation of specific dna binding by in vitro synthesized human glucocorticoid receptor. | we have used a dna-binding/immunoprecipitation assay to analyze the capacity of human glucocorticoid receptor (hgr), generated in rabbit reticulocyte lysates, to bind dna. in vitro translated hgr was indistinguishable from native hgr, as determined by migration on sodium dodecyl sulfate-polyacrylamide gels, sedimentation on sucrose density gradients, and reactivity with antipeptide antibodies generated against hgr. in addition, cell-free synthesized hgr was capable of specific binding to glucoco ... | 1991 | 1944294 |
| selective depletion in hiv infection of t cells that bear specific t cell receptor v beta sequences. | the mechanism of t cell depletion during infection with the human immunodeficiency virus (hiv) is unclear. examination of the repertoire of t cell receptor v (variable) regions in persons infected with hiv revealed the absence of a common set of v beta regions, whereas v alpha usage was normal. the lack of these v beta segments did not appear to correlate with opportunistic infections. the selective elimination of t cells that express a defined set of v beta sequences may indicate the presence o ... | 1991 | 1948066 |