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)

Regulation of the level of thyrotropin-releasing hormone (TRH) receptor (TRH-R) mRNA appears to involve both modulation of gene transcription and of mRNA degradation. To study regulation of TRH-R mRNA degradation and circumvent any physiological effect on transcription, we use cells stably transfected with mouse TRH-R cDNA under control of the constitutively active cytomegalovirus promoter. In stably transfected GH pituitary cells, we find that phorbol 12-myristate 13-acetate (PMA), like TRH, down-regulates TRH-R mRNA by increasing the rate of TRH-R mRNA degradation. In contrast, in stably transfected AtT-20 pituitary cells and in nonpituitary cell lines, neither TRH nor PMA decreased TRH-R mRNA levels. These findings are consistent with the idea that activation of protein kinase C leads to enhanced degradation of TRH-R mRNA in a cell-type-specific manner.
Mol Cell Neurosci 1994 Dec
PMID:Phorbol myristate acetate enhances degradation of TRH receptor mRNA in a pituitary cell type-specific manner. 770 31

In total, 4165 medaka (Oryzias latipes) oocytes were injected with three DNA constructs separately, and results showed that exogenous lacZ expression was transient and stage-dependent. The initiation of the transgene expression was at the mid-blastula stage for embryos derived from oocytes injected with pmiwZ, containing the long terminal repeat (LTR) of the Rous sarcoma virus, and with pCAGGS-lacZ, containing the enhancer and promoter of the immediate early gene of the human cytomegalovirus, respectively, whereas embryos derived from oocytes injected with pMoZtk, containing the LTR of the Moloney murine leukemia virus, started expression at the late-blastula stage. These reveal that the earliest onset of the exogenous lacZ gene should be by the mid-blastula stage. Therefore the mid-blastula transition phenomenon in embryogenesis known in other animal species exists in medaka embryos.
Mol Mar Biol Biotechnol 1995 Mar
PMID:Initiation of the transgenic lacZ gene expression in medaka (Oryzias latipes) embryos. 774 60

We demonstrated that MIF-1, identified initially as a binding activity that associated with the intron I element of the c-myc gene, consists of two polypeptides, the myc intron-binding peptide (MIBP1) and the major histocompatibility class II promoter-binding protein, RFX1. Using a polyclonal antiserum directed against either oligonucleotide affinity-purified MIBP1 or a peptide derived from RFX1, we showed that MIBP1 and RFX1 are distinct molecules that associate in vivo and are both present in DNA-protein complexes at the c-myc (MIF-1) and major histocompatibility complex class II (RFX1) binding sites. We have also found that MIBP1 and RFX1 bind to a regulatory site (termed EP) required for enhancer activity of hepatitis B virus. In addition, we have identified MIF-1-like sequences within regulatory regions of several other viral genes and have shown that MIBP1 binds to these sites in cytomegalovirus, Epstein-Barr virus, and polyomavirus. We have also demonstrated that the MIF-1 and EP elements can function as silencers in the hepatocarcinoma HepG2 and the cervical carcinoma HeLa cell lines. These findings indicate that MIBP1 and EP/RFX1 can associate in vivo and may regulate the expression of several distinct cellular and viral genes.
Mol Cell Biol 1995 Jun
PMID:The myc intron-binding polypeptide associates with RFX1 in vivo and binds to the major histocompatibility complex class II promoter region, to the hepatitis B virus enhancer, and to regulatory regions of several distinct viral genes. 776 Aug

The complete DNA sequence of equine herpesvirus 2 (EHV-2) strain 86/67 was determined. The genome is 184,427 bp in size and has a base composition of 57.5% G + C. Unusually for a herpesvirus, about a third of the sequence distributed in several large blocks appears not to encode proteins. The 79 open reading frames that were identified as probably polypeptide-coding are predicted to encode 77 distinct proteins. Amino acid sequence comparisons confirmed that EHV-2 is a gamma-herpesvirus that is genetically collinear with herpesvirus saimiri (HVS; a gamma 2-herpesvirus) and Epstein-Barr virus (EBV; a gamma 1-herpesvirus), with a closer relationship to the former. Moreover, EHV-2 specifies eight proteins that have counterparts in HVS but not in EBV and only a single protein that has a homologue in EBV but not in HVS (EBV BCRF1, which encodes an interleukin 10-like protein). EHV-2 also encodes three potential G protein-coupled receptors, one with a counterpart in HVS that is specific for alpha chemokines, another with a counterpart in human cytomegalovirus (a beta-herpesvirus), which is specific for beta chemokines, and a third that is assigned more tentatively and lacks detectable counterparts in other herpesviruses.
J Mol Biol 1995 Jun 09
PMID:The DNA sequence of equine herpesvirus 2. 778 7

Early experience with recombinant adenoviruses for gene transfer to airway epithelium suggests that these vectors are associated with the development of inflammation. The mechanisms for this are unclear, but previous work has shown that respiratory viruses can cause increased expression of intercellular adhesion molecule-1 (ICAM-1) on airway epithelial cells. We therefore hypothesized that recombinant adenoviruses may induce ICAM-1 expression and thereby facilitate the development of airway inflammation. To address this, primary cultures of human bronchial epithelial cells were examined for ICAM-1 expression by flow cytometry after infection with a serotype 5, E1/E3-deleted recombinant adenovirus containing the Escherichia coli LacZ reporter gene driven by the cytomegalovirus promoter (Ad.CMVlacZ). Compared with control cells, ICAM-1 expression was unchanged after infection with Ad.CMVlacZ, but increased after infection with wild-type adenovirus. Treatment of Ad.CMVlacZ-infected cells with interferon-gamma (IFN) resulted in increased ICAM-1 expression, but to a lower level than that seen in cells treated with IFN alone, indicating that recombinant adenovirus infection blunted IFN-induced up-regulation of ICAM-1. Adhesion of human leukocytes to human bronchial epithelial cells was not increased after Ad.CMVlacZ infection, thereby excluding an ICAM-1-independent increase in leukocyte-epithelial adhesion. The results for ICAM-1 expression were confirmed in vivo, as immunostaining of human bronchial xenografts infected with Ad.CMVlacZ revealed basilar epithelial staining with ICAM-1, but no increased expression on cells expressing beta-galactosidase. This study demonstrates that unlike other respiratory viruses, recombinant E1/E3-deleted adenovirus does not cause increased ICAM-1 expression on human bronchial epithelium in vitro or in vivo nor increased leukocyte adhesion in vitro.
Am J Respir Cell Mol Biol 1995 Feb
PMID:ICAM-1 expression on bronchial epithelium after recombinant adenovirus infection. 786 13

Owing to the persistence of viral DNA in leukocytes after primary CMV infection, detection of CMV DNA in these cells does not necessarily represent active infection. To identify CMV replication more precisely we have analysed immediate-early, early and late CMV transcripts by RNA amplification. The assay seems to be specific for active infection since no RNA-derived PCR products were obtained from healthy seropositive persons. The late UL83 transcript was detected in 80% of the patients with active CMV infections. Diagnosis of CMV replication by amplification of early and immediate-early transcripts was considerably less sensitive. In the case of continual CMV DNA detection in blood leukocytes by PCR without pp65 antigenemia the analysis of defined CMV transcripts would allow differentiation of active and non-active infection. In two cases the RNA assay became negative prior to DNA PCR analysis and pp65 antigen detection upon antiviral treatment, indicating that RNA amplification could be a suitable assay for early detection of the end of viral replication. No strong correlation was found between RNA detection and appearance of clinical symptoms. The development of CMV disease probably depends more on the extent of the functional impairment of the immune system.
Mol Cell Probes 1994 Aug
PMID:Identification of active cytomegalovirus infection by analysis of immediate-early, early and late transcripts in peripheral blood cells of immunodeficient patients. 787 68

We used polymerase chain reaction (PCR) to detect cytomegalovirus (CMV) deoxyribonucleic acid (DNA) in the bronchoalveolar lavages (BAL) of 16 CMV-infected patients with active disease. We also tested PCR on a control group of 20 patients including latently infected patients without evidence of active CMV infection. Results were compared with those of CMV culture and of a rapid method of diagnosis which detects CMV in BAL cells by nucleic acid hybridization. PCR allowed the diagnosis in 93% of the actively infected patients compared to 73% for the CMV culture. Among the 20 control patients without evidence of active CMV infection, PCR was negative in all the 24 BAL tested. Hybridization on BAL cells with the CMV probe detected nine out of 10 actively infected patients, but the specificity of the test was only 68.5%. In our experience, PCR appears to be at least as sensitive as CMV culture, it provides results faster and it performs better than the detection of the virus by hybridization on BAL cells. Only active CMV infection was detected with the PCR conditions used in our study. This suggests that the PCR can be applied to bronchoalveolar lavage fluids as a rapid method to detect CMV lung infection.
Mol Cell Probes 1994 Aug
PMID:Rapid diagnosis of cytomegalovirus lung infection by DNA amplification in bronchoalveolar lavages. 787 69

A tetracycline-controlled transrepressor protein has been engineered to silence transcriptional activities of eukaryotic promoters that are stably integrated into the chromatin of human cells. By fusing the KRAB domain of human Kox1 to the Tet repressor derived from Tn10 of Escherichia coli, a tetracycline-controlled hybrid protein (TetR-KRAB) was generated and constitutively expressed in HeLa cells. The TetR-KRAB protein binds to tet operator (tetO) sequences in the absence but not in the presence of tetracycline. When TetR-KRAB bound to tetO sequences upstream of the immediate-early promoter-enhancer of human cytomegalovirus (CMV), the expression of a CMV-driven luciferase reporter construct (ptetO7-CMV-L) was repressed in transient transfection experiments. This silencing was found to operate on different promoters and from tetO sequences placed more than 3 kb from the transcriptional start site. We constructed a stable, doubly transfected cell line (TIS-10) carrying a chromosomally integrated ptetO7-CMV-L reporter construct and expressing the TetR-KRAB protein. Upon addition of tetracycline, luciferase expression was induced more than 50-fold above the baseline level, with half-maximal induction by 2 days. Furthermore, a protein of around 110 kDa was found to coimmunoprecipitate with the TetR-KRAB fusion protein. This protein might play a role as an adaptor protein mediating the silencing exerted by the TetR-KRAB protein. The TetR-KRAB silencing system should be useful as a genetic switch for regulating the expression of chromosomally integrated heterologous and endogenous genes present in mammalian genomes.
Mol Cell Biol 1995 Apr
PMID:Tetracycline-reversible silencing of eukaryotic promoters. 789 84

We have undertaken to characterize the role of cytoplasmic 5'-nucleotidase (EC 3.1.3.5) in the phosphorylation of the anti-herpes simplex virus and anti-human cytomegalovirus agent ganciclovir (GCV) in MOLT-4 cells, a human T cell line adapted to grow in suspension culture. The rate of formation of GCV triphosphate was found to be approximately doubled by preincubation of nontransfected MOLT-4 cells with agents that cause the accumulation of IMP, such as ribavirin (20 microM) and mycophenolic acid (1 microM), and the reaction rate was found to be unaffected by high levels of thymidine (100 microM). With herpes simplex virus-1 thymidine kinase (HStk) gene-transduced MOLT-4 cells, the rate of GCV phosphorylation was approximately 40-fold faster than that in uninfected cells and, in marked contrast to uninfected cells, the reaction was significantly inhibited both by IMP dehydrogenase inhibitors and by thymidine. These latter effects appear to be the result of 1) the accumulation of high levels of dTTP in IMP dehydrogenase inhibitor-treated cells, with consequent feedback inhibition of HStk, and 2) direct competitive substrate inhibition by thymidine of the HStk-catalyzed phosphorylation of GCV. Thus, agents that enhance 5'-nucleotidase-catalyzed phosphorylation of GCV in uninfected cells do not play a similar role in HStk-transfected cells, a consequence of the quantitative predominance of the viral thymidine kinase-catalyzed reaction over that attributable to endogenous cytoplasmic 5'-nucleotidase.
Mol Pharmacol 1994 Apr
PMID:Effects of IMP dehydrogenase inhibitors on the phosphorylation of ganciclovir in MOLT-4 cells before and after herpes simplex virus thymidine kinase gene transduction. 791 Mar 73

Normal human bronchial epithelial (NHBE) cells are the putative progenitor cells of all types of lung cancer. NHBE cells immortalized by SV40 T-antigen retain many characteristics of the primary cells and are a useful model for investigating the role of oncogenes, tumor suppressor genes, and certain chemical carcinogens in the molecular pathogenesis of lung cancer. In this study, SV40 T-antigen-positive cells (BEAS-2B) were characterized for their metabolic functions and were shown to continue to express epoxide hydrolase, glutathione S-transferase pi, glutathione peroxidase, and catalase. To increase their metabolic activity towards human procarcinogens, human cytochrome P450 1A2 (CYP1A2) was stably expressed by introducing CYP1A2 cDNA into BEAS-2B cells either by infection with a high-titer recombinant retrovirus (pXT-1A2) or by transfection with a CYP1A2 expression vector (pCMV1A2), which produced the cell lines B-1A2 and B-CMV1A2, respectively. Cell lines established with either expression system expressed enzymatically active CYP1A2 protein and were 50- to 400-fold more sensitive to the cytotoxic effect of the carcinogen aflatoxin B1 (AFB1) than the corresponding control cell lines. The cytotoxic effects of AFB1 were paralleled by increased metabolism of AFB1 and enhanced formation of the AFB1-N7 guanine adduct in B-CMV1A2 cells. Cytotoxicity and adduct formation correlated with a significantly higher protein expression of CYP1A2 by the cytomegalovirus promoter-driven plasmid. Since this human epithelial cell line is the precursor cell type of lung cancer, has normal phase II enzymes, and exhibits highly reproducible expression of phase I enzymes, this in vitro model should aid in the evaluation of putative human carcinogens and anticarcinogens.
Mol Carcinog 1994 Oct
PMID:Activation of promutagens in a human bronchial epithelial cell line stably expressing human cytochrome P450 1A2. 791 94


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