Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
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The tyrosine aminotransferase (TAT) gene is expressed in a tissue and developmental-specific manner. In addition, this gene is regulated by glucocorticoid and polypeptide hormones and its expression is affected when a regulatory region near the albino locus of the mouse is deleted. In order to allow studies of the molecular effects of these deletion mutations we have isolated and characterized the mouse TAT gene. The gene is 9.2 x 10(3) bases in length and consists of 12 exons which give rise to a 2.3 x 10(3) base long messenger RNA. The DNA sequence at the 5' end of the gene was determined and compared with the corresponding sequence of the rat tyrosine aminotransferase gene. The sequence comparison showed extensive homology over the entire region sequenced. In addition, DNA: DNA heteroduplex studies between the mouse and rat tyrosine aminotransferase genes revealed that this homology extends over the entire gene and its flanking sequences. The mouse tyrosine aminotransferase gene has been mapped distal to the serum esterase-1 locus on mouse chromosome 8, using a restriction fragment length polymorphism between two mouse species. Since the albino deletions are located on mouse chromosome 7, the assignment of the TAT gene to chromosome 8 suggests that a regulatory factor(s) affecting TAT gene expression acts in trans.
J Mol Biol 1985 Aug 05
PMID:Isolation, characterization and chromosomal mapping of the mouse tyrosine aminotransferase gene. 241 15

Beta-glucuronidase and N-AS-D-chloroacetate esterase cytochemistry have been applied to rat liver sinusoidal endothelial cells and Kupffer cells. Both staining procedures allowed a clear-cut differentiation of either cell type. Kupffer cells which had been stained with beta-glucuronidase showed a positive reaction, whereas sinusoidal endothelial cells were completely negative. If the chloroacetate reaction was used, the former stained diffusely while the latter showed a characteristic granular staining pattern. Identity and purity of sinusoidal endothelial cells and Kupffer cells was validated by transmission and scanning electron microscopy as well as by the pattern of released eicosanoids which is characteristic for either cell type. These two staining techniques are a valuable addition to the peroxidase reaction commonly applied for differentiation.
Virchows Arch B Cell Pathol Incl Mol Pathol 1988
PMID:Beta-glucuronidase and chloroacetate-esterase staining discriminates rat liver sinusoidal endothelial cells from Kupffer cells in primary culture. 245 75

In vitro assessment of the efficacy/capacity of toxicants (e.g., cancer chemotherapeutic agents, environmental pollutants, etc.) to damage/kill cells and/or inhibit growth (cell duplication) requires accurate measurement of target cell viability as a function of exposure. Rapid measurement of viability, such as can be achieved employing fluorescent probes of metabolic function in combination with instrumental analysis, is highly desirable. However, we observe that exposure to chemicals (of unrelated type) complicates the interpretation of viability data and, in the case of perturbed cells, questions the validity of viability growth assays based on intrinsic enzyme activity. Viability commonly is determined flow cytometrically (FCM) by the carboxyfluorescein diacetate (CFDA)/propidium iodide (PI) assay. Nonfluorescent CFDA is taken up by diffusion and converted via cytoplasmic esterase-catalyzed hydrolysis to carboxyfluorescein (CF), a negatively charged fluorescent molecule that is retained (incompletely) by the cell. As such, if CF fluorescence intensity is a relative measure of enzyme activity, it also can be considered an index of cellular vigor (metabolic rate). It is generally accepted that the viable cell excludes both basic dyes, such as PI, and acidic dyes, such as trypan blue, and uptake is indicative of irreversible cellular injury presaging cell death. We observe that, following incubation for 4 h with 0.5-1.0 microM tributyltin (TBT), a potent environmental toxicant, murine erythroleukemic cells (MELC) exhibit enhanced (supranormal) CF fluorescence compared to control cells. Apparent cell volume (ACV) is unaltered, and because such cells exclude PI, they are considered viable in terms of the CFDA/PI assay. However, rate of growth (increase in cell number over 48 h) is depressed, suggesting that supranormal CF fluorescence, even in the absence of PI uptake, is indicative of cellular perturbation. In effect, although CF fluorescence is the product of an enzyme-catalyzed reaction and, therefore, an indicator of vital function (enzyme activity), it apparently is not a reliable index of cellular vigor. At higher TBT concentrations (greater than 1.0, but less than 50.0 microM), the cells exhibit both increased CF fluorescence and PI fluorescence and are growth inhibited. MELC exposed to the cancer chemotherapeutic agents adriamycin, m-AMSA, or crisnatol (Burroughs Wellcome 770U82) also exhibit increased cellular CF fluorescence. However, rate of growth is decreased and ACV increased. The latter, measured either as a function of electrical resistance (Coulter volume) or by the FCM parameter axial light loss could account for the increase in mean CF fluorescence.(ABSTRACT TRUNCATED AT 400 WORDS)
Mol Toxicol
PMID:Limitations of the fluorescent probe viability assay. 249 Sep 80

We have demonstrated previously in a mouse model that effective chemotherapy against Schistosoma mansoni with praziquantel (PZQ) is dependent upon an intact host antibody response. In the same study, it was found that worms recovered from PZQ-treated animals display surface-bound antibodies. In order to identify the target antigens of the antibodies involved in the synergy between PZQ and the immune response, monoclonal antibodies (mAbs) and polyclonal antisera recognizing different tegumental components were tested by indirect immunofluorescence (IF) assay for their ability to bind in vitro to the surface of 6-week-old schistosomes perfused from nude (athymic) mice 1 h after PZQ treatment. Nude mice were used as hosts because worms from these animals were found to lack bound anti-schistosome antibodies. Only 5 of the 21 antibodies tested reacted with drug-treated worms. This indicated that the damage caused by PZQ to the schistosome tegument is restricted to specific tegumental components. Of the positive reactions, one group of antibodies gave IF patterns different from, whereas the other group gave IF reactions similar to those seen with worms perfused from immunologically intact mice. Antibodies against a schistosome esterase and alkaline phosphatase produced reaction patterns in the former category. In contrast, two out of three monoclonal antibodies recognizing different epitopes on a 200-kDa glycoprotein abundant in worm tubercles gave IF patterns very similar to those observed on schistosomes from drug-treated, intact mice. The biological significance of these reactions was confirmed by demonstrating that transfer of one of the positive monoclonal antibodies to 6-week-infected, B cell-depleted (mu-suppressed) mice reconstitutes the efficacy of PZQ treatment to normal levels. The above results suggest that the antibodies involved in the mechanism of action of PZQ react with a limited set of antigens. Furthermore, they implicate the 200-kDa tubercle protein as a major target of this response in naturally infected hosts.
Mol Biochem Parasitol 1989 May 01
PMID:Role of host antibody in the chemotherapeutic action of praziquantel against Schistosoma mansoni: identification of target antigens. 249 7

Young adult Wistar rats received 40 mg/kg of cyclosporin perorally for 21 days. Cyclosporin induced almost total disappearance of thymic medulla, whereas the cortex remained preserved. Although the density of cortical macrophages did not change significantly, their characteristics altered markedly and they became enlarged and rounded. In addition to an increase in acid phosphatase and nonspecific esterase activities, cortical macrophages developed very strong succinic dehydrogenase and chloroacetate esterase activities and a fine, granular, aldehyde fuchsin-positive cytoplasmic content. However, these cytoplasmic granules were PAS-negative and were not sudanophilic. Cortical macrophages retained their normal antigenic properties (which were studied by the use of ED1, ED2 and R-MC 41 monoclonal antibodies). Phagocytic cells in the remaining medullary islands retained their usual characteristics. The changes in cortical macrophages after cyclosporin treatment are discussed, especially in relation to the characteristics of macrophages of the cortico-medullary zone in the normal rat thymus.
Virchows Arch B Cell Pathol Incl Mol Pathol 1989
PMID:Macrophages of the rat thymus after cyclosporin treatment. Histochemical, enzymehistochemical and immunohistochemical study. 256 84

The enzyme and immunohistochemical features of lymphnodes showing sinus histiocytosis have been studied. Sinus histiocytes with phenotype OKM1+ OKT4+ Leu3a+ To5+ OKIal- showed strong acid phosphatase and non-specific esterase, weak endogenous peroxidase and no ATPase activities. In nine out of ten lymph nodes, paracortical collections of dendritic OKT6+ OKIal+ cells were observed. In two of the four cases studied these dendritic cells showed strong ATPase activity. We suggest that the dendritic OKT6+ OKIal+ ATPase+ interfollicular cells represent newly arrived veiled cells (VC) which have entered the lymph node by the afferent lymph, settled in the interfollicular area and are probably involved in the induction of a cellular immune response. OKT6+ OKIal+ ATPase+ VC may subsequently transform into mature, OKT6- OKIal+ ATPase+ interdigitating reticulum cells which are involved in the negative feedback of the cellular immune response. The association with sinus histiocytosis is probably related to the fact that an increase in mononuclear phagocytes in the afferent lymph is accompanied by a relative increase in VC. Our results demonstrate that in lymph nodes showing sinus histiocytosis, two cell types increase in number, i.e. an Ia- sinusoidal cell, engaged in phagocytosis of foreign material, and an Ia+ dendritic cell in the interfollicular area, probably involved in the induction of a cellular immune response.
Virchows Arch B Cell Pathol Incl Mol Pathol 1985
PMID:The paracortical area in reactive lymph nodes demonstrating sinushistiocytosis. An enzyme- and immunohistochemical study. 258 Mar 89

Regulation of the metabolism of [3H]25-hydroxyvitamin D3 ([ 3H]25-(OH)D3) in vitro to material with the characteristics of [3H]24,25-dihydroxyvitamin D3 ([3H]24,25-(OH)2D3) has been studied in the human promyelocytic cell line HL60. Synthesis of 24,25-(OH)2D3 was induced in a dose-dependent manner in cells pretreated with 0.1-100 nM 1 alpha,25-dihydroxyvitamin D3 (1 alpha,25-(OH)2D3) for 4 days. This treatment also inhibited cell proliferation and stimulated differentiation to a macrophage phenotype that was characterized by staining for non-specific esterase (NSE) activity. The ability to synthesize [3H]24,25-(OH)2D3 from [3H]25-(OH)D3 and the expression of NSE activity both responded to changes in concentration of 1 alpha,25-(OH)2D3 in the culture medium in a parallel manner. Synthesis of [3H]24,25-(OH)2D3 was linear when the incubation time was between 1 and 8 h and the cell number between 1 and 12 x 10(6) cells/incubation. The optimum substrate concentration for its synthesis was 125 nM, giving an apparent Michaelis constant of 360 nM. The identity of the [3H]24,25-(OH)2D3 synthesized by these cells was confirmed by co-chromatography with authentic 24,25-(OH)2D3 on normal-phase and reverse-phase high-performance liquid chromatography systems and by its reaction to sodium-m-periodate. Cells that had been exposed to 100 nM 1 alpha,25-(OH)2D3 for 4 days synthesized 2.17 +/- 0.07 (S.E.M.) pmol 24,25-(OH)2D3/10(6) cells per h.(ABSTRACT TRUNCATED AT 250 WORDS)
J Mol Endocrinol 1989 Nov
PMID:Metabolism of 25-hydroxyvitamin D3 to 24,25-dihydroxyvitamin D3 and its sensitivity to ketoconazole in 1 alpha,25-dihydroxyvitamin D3-differentiated HL60 cells. 259 Mar 83

In vitro transcription of D. virilis esterase S gene and it's dependence on reaction conditions and template configuration was studied. Localization of major in vivo transcription initiation points were proved. In vitro transcription can start from alternative points, localised at positions -125 and -342. Dependence of the transcription efficiency of the presence of the 5'-flanking region is shown.
Mol Biol (Mosk)
PMID:[In vitro transcription of esterase S gene in Drosophila virilis]. 263 37

The level of resistance to infection in inbred mice with the murine malaria species Plasmodium chabaudi AS is genetically determined. Resistant C57BL/6, which are able to eliminate the parasite by 4 weeks, develop marked splenomegaly and survive the infection. Susceptible A/J mice, which succumb to infection (mean survival time = 10 days), develop only minimal splenomegaly. In order to determine if gross differences in the organization, number, and type of spleen cells are related to the outcome of infection with P. chabaudi AS, the development of splenomegaly was examined by enzyme and immunohistochemical methods during the first week after infection. Cryostat sections of spleens removed from normal animals of both strains and at 4 and 7 days after intraperitoneal infection with 10(6) parasitized erythrocytes were stained for enzyme (acid phosphatase and nonspecific esterase) and immunohistochemistry with conventional monoclonal antibodies against T cells, B cells, and macrophages as well as with novel rat anti-mouse monoclonal antibodies which define discrete subpopulations of macrophages in the mouse spleen. The livers of normal and infected animals of each strain were also examined. The results of this study demonstrate (1) differences between normal, uninfected B6 and A/J mice in the organization and number of one subpopulation of macrophages in the spleen, the marginal metallophilic macrophages, and (2) marked histological changes in the spleen and liver during the course of infection in both resistant C57BL/6 and susceptible A/J mice. These changes include depletion of cells from the marginal zone of the spleen which, in the case of the marginal metallophilic macrophages, appears to be more severe in susceptible A/J mice.
Exp Mol Pathol 1989 Aug
PMID:Histological changes in the spleen and liver of C57BL/6 and A/J mice during Plasmodium chabaudi AS infection. 278 81

The gene encoding pectin methyl esterase (pme) has been cloned from Erwinia chrysanthemi B374. Expression of pme in Escherichia coli allowed the enzyme to be characterized. Pectin methyl esterase (PME) was found to have an apparent molecular weight of 36,000 Daltons and an isoelectric point of approximately 9.9. The structural gene was sequenced and consists of a 1098-bp open reading frame encoding a polypeptide of 39,318 Daltons, which includes an amino-terminal signal peptide. The isolation of the Erwinia gene provides a simple method for the production of PME free from depolymerizing pectinases thereby extending its potential uses.
Mol Microbiol 1988 Mar
PMID:Molecular cloning and nucleotide sequence of the pectin methyl esterase gene of Erwinia chrysanthemi B374. 283 15


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