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)

Human progesterone receptors (PR) in T47D breast cancer cells are synthesized as two different sized proteins, PR-A [94 kilodaltons (kDa)] and PR-B (120 kDa). Progestin addition to cells (in vivo) causes a 2-fold increase in total phosphorylation of PR and an increase in the apparent mol wt of both PR-A and PR-B on sodium dodecyl sulfate (SDS)-gels. Time-course experiments showed that increased PR phosphorylation that results from hormone addition is a multistep process and involves a rapid increase into total 32P labeling that takes place before the more slowly occurring phosphorylation(s) responsible for the change in electrophoretic mobility of PR on SDS-gels. As an approach to test whether phosphorylation is involved in regulating PR activity, we have examined the effects of cellular modulators of protein phosphorylation on PR-mediated target gene transcription in vivo using a T47D cloned cell line containing a stably transfected mouse mammary tumor virus-chloramphenicol acetyltransferase construct. Treatment with 8-bromo-cAMP (activator of cAMP-dependent protein kinases) or okadaic acid (protein phosphatase-1 and -2A inhibitor) did not stimulate target gene expression in the absence of progestin. When added together with progestin, either compound augmented PR-mediated target gene transcription by 3- to 4-fold. The cyclic nucleotide-dependent protein kinase inhibitor H8 completely blocked target gene responsiveness to hormone. Neither 8-bromo-cAMP, okadaic acid, nor H8 altered the hormone- or DNA-binding activities of PR, as measured in vitro or affected cellular concentrations of PR. These agents, therefore, appeared to selectively modulate PR transcriptional activity. Moreover, none of these compounds altered expression from a control reporter gene, pSV2CAT, indicating that these agents affect PR-mediated processes directly and are not acting through a general effect on transcription. Effects on PR phosphorylation were assessed by measuring 32P labeling of PR in vivo. None of these treatments had a substantial effect on the extent of total 32P labeling of immune isolated PR or on the phosphorylation(s) responsible for PR up-shifts on SDS-gels. This suggests that these agents modulate PR transcriptional activity either through phosphorylation of another protein intimately involved in PR-mediated transcription or through modification of a key site(s) not measurable as a change in total PR phosphorylation or electrophoretic mobility on SDS gels.
Mol Endocrinol 1992 Apr
PMID:Effects of hormone and cellular modulators of protein phosphorylation on transcriptional activity, DNA binding, and phosphorylation of human progesterone receptors. 131 49

Turnover of the chloramphenicol acetyltransferase (cat) messenger RNA in Escherichia coli was investigated by analysis of cellular mRNA decay intermediates and the transcript sequence. Analysis of the sequence has revealed the presence of a repetitive extragenic palindromic (REP) element at the 3' end of the transcript as well as several 5'-UUAU-3' sequences, two elements which have roles in modulating turnover of other E. coli mRNAs. For cat mRNA, however, removal of the REP sequence has no effect on the half-life of the transcript, indicating that the REP sequence does not stabilize the upstream region of this message. Results from mapping of the mRNA decay products by several techniques suggest that the message is instead subject to endonucleolytic attack at five sites 5' of the REP element. The sequence UUAU is present at three of these five sites. It also appears that the cat mRNA is sequentially cleaved in a 3' to 5' direction during turnover of this mRNA in vivo. A model for cat mRNA turnover is discussed.
Mol Microbiol 1992 May
PMID:Characterization of cat messenger RNA decay suggests that turnover occurs by endonucleolytic cleavage in a 3' to 5' direction. 131 85

Human cytomegalovirus (HCMV) can infect monocytes and macrophages. The immediate early one (IE1) gene product of HCMV positively regulates its own expression, as well as the expression of the interleukin-1 beta (IL-1) gene. This study describes the IL-1 promoter proximal region required for upregulation of IL-1 gene expression by the HCMV IE1 or IE1 plus IE2 gene products. An IL-1 chloramphenicol acetyltransferase (CAT) construct containing the IL-1 genomic upstream sequence from position -1097 to +14 and four additional IL-1CAT plasmids containing progressive deletions of the -1097 to -131 sequence were used to evaluate the effect of the HCMV IE gene products on IL-1 gene expression. IL-1CAT plasmids were transfected into a monocytic cell line, THP-1, with plasmids containing either the IE promoter-regulatory region upstream of the bona fide IE1 (pIE1), IE2 (pIE2), or IE1+2 genes (pIE1+2) or a control plasmid containing the IE promoter-regulatory region alone (pLink760). In the presence of pIE1+2, there was an approximate 15-fold increase in CAT activity compared with the control, pLink760, in cells with CAT plasmids containing the -1097 to +14 IL-1 sequence. Plasmids with progressive deletions of this sequence, including the plasmid containing the shortest upstream segment (-131 to +14) also had an approximate 15-fold increase in CAT activity. The upregulation of IL-1 expression was mediated, primarily, by IE1 and not by IE2. This effect was promoter specific because an IL-1CAT plasmid with a complete deletion of the proximal promoter elements (-234 to +146) did not respond to the HCMV IE gene products.(ABSTRACT TRUNCATED AT 250 WORDS)
Am J Respir Cell Mol Biol 1992 Jun
PMID:The immediate early genes of human cytomegalovirus require only proximal promoter elements to upregulate expression of interleukin-1 beta. 131 94

The expression of the principal opioid peptide gene, preproenkephalin A, is exquisitely regulated by primary afferent inputs to the spinal and medullary dorsal horns. This regulated expression in response to neural synaptic activity has been referred to as trans-synaptic regulation. To define which DNA regions could mediate this trans-synaptic regulation, transgenic 'HEC' mice whose genomes include 193 bp of the human preproenkephalin A promoter fused to a chloramphenicol acetyltransferase (CAT) reporter gene were studied. Mice received unilateral electrical stimulation of the trigeminal ganglion or adjuvant injection into the hindpaw, stimuli known to regulate dorsal horn proenkephalin expression in vivo. CAT activity conferred by this promoter displayed trans-synaptic upregulation with both stimuli. Although the level of the upregulation was 2- to 3-fold higher than the change in the wild type gene, several features of this induction paralleled aspects of the behavior of the wild-type gene: the rapidity of responses to trigeminal ganglion stimulation, the stimulation intensity dependence of responses to trigeminal ganglion stimulation and the time course of upregulation noted following adjuvant injection. Regulatory proteins binding to this restricted promoter region are thus likely to mediate aspects of dorsal horn enkephalin regulation by pain and other somatic stimuli.
Brain Res Mol Brain Res 1992 Apr
PMID:Primary afferent stimulation acts through a 193 base pair promoter region to upregulate preproenkephalin expression in dorsal horn of transgenic mice. 131 94

To examine the role of nuclear retinoic acid (RA) receptors (RARs) in the regulation of squamous differentiation in normal human epidermal keratinocytes (NHEK), we analyzed binding activity, mRNA expression, and transcriptional activity of the endogenously expressed RARs. Specific RA-binding activity eluted from size-exclusion HPLC with an apparent mol wt of 50 kilodaltons and was predominantly (greater than 95%) associated with the NHEK nuclear cell fraction. This RAR-binding activity represented in part the expression of RAR alpha and RAR gamma genes, whose transcripts were expressed in similar abundance in undifferentiated NHEK. Differentiation resulted in lower mRNA expression of RAR alpha relative to the mRNA expression of RAR gamma. Treatment of NHEK cells with 10(-6) M RA did not induce expression of RAR beta mRNA. Similarly, three squamous cell carcinoma cell lines derived from human skin and oral cavity expressed RAR alpha and RAR gamma transcripts, but not RAR beta transcripts. Transfection of NHEK with chloramphenicol acetyltransferase (CAT) reporter plasmids indicated that the endogenously expressed RARs could activate transcription through the RAR beta response element in a concentration-dependent manner with doses of 10(-9) M RA and higher. CAT expression was not activated through TRE, a palindromic thyroid hormone response element with purported RA responsiveness. The competitive binding of benzoic acid derivatives of RA to RAR correlated with the ability of each analog to suppress mRNA expression of the squamous cell markers, involucrin, type I transglutaminase, and SQ37, and to activate transcription of the RAR beta response element-CAT reporter. These results demonstrate that the control of NHEK differentiation by RA is consistent with the interaction of the retinoid with RAR and the regulation of transcription by that ligand-receptor complex.
Mol Endocrinol 1992 May
PMID:Retinoic acid receptors as regulators of human epidermal keratinocyte differentiation. 131 2

Human pregnancy-specific glycoproteins (PSGs) are a family of closely related placental proteins that, together with the carcinoembryonic antigen members, comprise a subfamily within the immunoglobulin superfamily. To facilitate study of the control of PSG expression, we immortalized human placental cell lines with adenovirus-origin-minus (ori-)-simian virus-40 (SV40) recombinant viruses containing either wild-type or temperature-sensitive (ts) A mutants of SV40. Cells transformed with the SV40 tsA chimera (HP-A1 and HP-A2), but not the SV40 wild-type chimera (HP-W1), were temperature sensitive for transformation. All three cell lines expressed trophoblast-specific genes, including PSG and the alpha- and beta-subunits of hCG. Human CG alpha expression was greatly stimulated by (Bu)2cAMP in all three cell lines; shifting HP-A1 and HP-A2 cells to the nonpermissive temperature (39.5 C) further increased hCG alpha expression. At both 33 C (permissive temperature) and 39.5 C, the transformed placental cells expressed PSG mRNAs of 2.2 and 1.7 kilobases; expression was greatly stimulated by sodium butyrate. In the absence of an inducer, the three placental lines synthesized a PSG of 64 kilodaltons (kDa). In the presence of butyrate, they synthesized PSGs of 72, 64, and 54 kDa, similar to the placental PSGs. However, in placenta the predominant species is the 72-kDa product. At 39.5 C, butyrate selectively increased synthesis of the 72-kDa PSG in HP-A1 and HP-A2 cells. To characterize PSG promoter activity, we constructed chloramphenicol acetyltransferase (CAT) fusion genes containing -809 to -44 basepairs up-stream of the translational start site of the PSG6 gene. Using transient expression assays, we demonstrated that the -809/-44 region of the PSG6 gene contained cis-acting sequences that can direct CAT expression in human placental cells. Sodium butyrate, which stimulates PSG expression, greatly increased CAT activity, indicating that butyrate-induced PSG expression is regulated primarily at the level of gene transcription.
Mol Endocrinol 1992 May
PMID:Immortalization of virus-free human placental cells that express tissue-specific functions. 131 3

Genomic clones containing 1.7 kilobases of the 5'-flanking region of the rat TSH receptor (TSHR) plus coding sequence from the ATG initiation codon [1 basepair (bp)] to the start of the first intron (170 bp) have been isolated and characterized. RNAase protection, primer extension, and cDNA sequences cloned by the anchored polymerase chain reaction identified multiple transcriptional start sites, the major ones clustered between -89 to -68 bp. This portion of the 5'-flanking region has neither a TATA nor a CCAAT box, is GC rich but has no GC box motif, and has features of promoters seen in "housekeeping" genes. Chimeras containing 1.7 kilobases (-1707 to -2 bp) of the 5'-flanking region, or deletions thereof, and the bacterial chloramphenicol acetyltransferase (CAT) gene expressed significant CAT activity when transfected into rat thyroid cell lines, FRTL-5 and FRT, but not BRL rat liver or HeLa cells. TSH decreased CAT activity in the FRTL-5 thyroid cells that had been stably transfected with the TSHR-CAT chimeric constructs. Negative regulation of promoter activity by TSH was duplicated by 10 microM forskolin in FRT thyroid cells, which express no TSHR mRNA. Deletion analyses indicated that a "minimal" region, exhibiting promoter activity, tissue specificity, and negative regulation by TSH, is located between -195 and -39 bp; this region is highly conserved in rat and human TSHR genes. Differential digestion of genomic DNA by MspI and HpaII revealed that the TSHR promoter is methylated in FRT, but not FRTL-5, cells; methylation of the promoter may be associated with loss of endogenous TSHR gene expression in FRT cells.
Mol Endocrinol 1992 May
PMID:Characterization of the 5'-flanking region of the rat thyrotropin receptor gene. 131 4

Transcription of the complete mouse mammary tumor virus (MMTV) proviral genome in mouse cells is controlled by a strong promoter in its long terminal repeat. In the mouse T lymphoma EL4, there is a second, activation-dependent transcriptional initiation site within the envelope (env) gene, from which a short mRNA is generated, encoding the open reading frame of the long terminal repeat. We now report the isolation of a segment of the MMTV env gene (called META, for MMTV env transcriptional activator) which has the expected transcription-activating properties seen in EL4.E1 cells. Namely, it induces activation-dependent, T-lymphocyte-specific transcription of a chloramphenicol acetyltransferase reporter gene. It is active in mouse or human T-helper lymphocyte lines when they are stimulated to transcribe lymphokine genes but is inactive in unstimulated T-helper cells, fibroblasts, a cytotoxic T-lymphocyte line, and a mastocytoma cell line. Its activity is inhibited by cyclosporin A, a specific inhibitor of lymphokine transcription. Several forms of the META have been isolated from EL4.E1 cells, a mouse T-helper cell hybridoma, and from BALB/c spleen cells. Linked to the heterologous thymidine kinase promoter, a 400-bp portion of it is an inducible, orientation-independent, and cyclosporin A-sensitive transcriptional activator in T-helper cells.
Mol Cell Biol 1992 Jul
PMID:An activation-dependent, T-lymphocyte-specific transcriptional activator in the mouse mammary tumor virus env gene. 132 Jan 98

Transcriptional activation of human heat shock protein (HSP) genes by heat shock or other stresses is regulated by the activation of a heat shock factor (HSF). Activated HSF posttranslationally acquires DNA-binding ability. We previously reported that quercetin and some other flavonoids inhibited the induction of HSPs in HeLa and COLO 320DM cells, derived from a human colon cancer, at the level of mRNA accumulation. In this study, we examined the effects of quercetin on the induction of HSP70 promoter-regulated chloramphenicol acetyltransferase (CAT) activity and on the binding of HSF to the heat shock element (HSE) by a gel mobility shift assay with extracts of COLO 320DM cells. Quercetin inhibited heat-induced CAT activity in COS-7 and COLO 320DM cells which were transfected with plasmids bearing the CAT gene under the control of the promoter region of the human HSP70 gene. Treatment with quercetin inhibited the binding of HSF to the HSE in whole-cell extracts activated in vivo by heat shock and in cytoplasmic extracts activated in vitro by elevated temperature or by urea. The binding of HSF activated in vitro by Nonidet P-40 was not suppressed by the addition of quercetin. The formation of the HSF-HSE complex was not inhibited when quercetin was added only during the binding reaction of HSF to the HSE after in vitro heat activation. Quercetin thus interacts with HSF and inhibits the induction of HSPs after heat shock through inhibition of HSF activation.
Mol Cell Biol 1992 Aug
PMID:Inhibition of the activation of heat shock factor in vivo and in vitro by flavonoids. 132 38

The transgenic mouse strain CAT40 carries in its germ line one copy of a DNA construct consisting of the chloramphenicol acetyltransferase gene and the immunoglobulin heavy-chain enhancer. We show that transgene integration has resulted in a recessive lethal mutation that leads to death of homozygous CAT40 embryos shortly after implantation. The transgene has integrated adjacent to the 3' end of the gene coding for the beta subunit of the brain-specific Ca2+/calmodulin-dependent protein kinase II (Camk-2). The complete cDNA sequence of the Camk-2 gene and most of its exon/intron structure was determined. The deduced amino acid sequence is highly homologous to the previously described rat protein. The chromosomal location of the Camk-2 locus was mapped by interspecific backcross analysis to the proximal region of mouse chromosome 11. This region lacks previously identified recessive embryonic lethal mutations. During embryonic development, Camk-2-specific transcripts are first seen in the head section of 12.5-day-old embryos, and in adult mice the gene is expressed almost exclusively in the brain. Although transcription of the Camk-2 gene in heterozygous CAT40 mice is affected by transgene integration, it is unlikely that this gene is responsible for the mutant phenotype, since it is not expressed in blastocysts and the first transcripts during normal development are detected after the death of homozygous CAT40 embryos. Transgene integration is accompanied by a large deletion of cellular DNA; death is therefore most likely caused by the loss of a gene or genes that are important for early postimplantation development.
Mol Cell Biol 1992 Aug
PMID:Structure, expression, and chromosome location of the gene for the beta subunit of brain-specific Ca2+/calmodulin-dependent protein kinase II identified by transgene integration in an embryonic lethal mouse mutant. 132 43


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