No correlation between binding of glucocorticosteroids to specific cytoplasmic proteins in vivo and enzyme induction in the rat liver

Time- and dose-dependence of the formation of the different cytoplasmic hormone-protein complexes were studied in the rat liver after administration in vivo of [3H]cortisol or [3H]dexamethasone and compared with the stimulation of RNA polymerase B and induction of tyrosine aminotransferase and tryptophan oxygenase. No correlation could be found between formation in vivo of any of the five cytoplasmic hormone-protein complexes found and stimulation of RNA polymerase B activity or enzyme induction. After administration of [3H]cortisol, different metabolites of cortisol could be demonstrated in the isolated hormone-protein complexes. No time- or dose-dependence of the metabolite patterns could be observed after application of hormone doses that were in the range of the biologically active doses. After administration of [3H]dexamethasone, the same hormone-protein complexes were observed, which contained, however, the injected steroid instead of metabolites. These results seem to indicate that the cytoplasmic binding components present in the rat liver are enzymes involved in the metabolism of the glucocorticosteroids and that dexamethasone binds to these enzymes as a substrate analogue.

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Enzyme induction in rat liver: The effects of Be2+in vivo

Bioscience Reports ◽

10.1007/bf01114907 ◽

1981 ◽

Vol 1 (3) ◽

pp. 217-222 ◽

Cited By ~ 7

Author(s):

Margery G. Ord ◽

Lloyd A. Stocken

Keyword(s):

Protein Kinase ◽

Rat Liver ◽

Enzyme Induction ◽

Orotic Acid ◽

Tyrosine Aminotransferase ◽

Cytoplasmic Protein ◽

Ribonucleoprotein Particles ◽

Liver Nuclei

Rats given an LD50 dose of Be2+ showed reduced activities of ornithine decarboxytase and tyrosine aminotransferase in liver in response to dexamethasone induction. Control fed animals showed ‘superinduction’. Be2+ also inhibited the uptake of [3H]orotic acid into rapidly labelled RNA of ribonucleoprotein particles extracted from liver nuclei in isomolar solutions at pH 8.0. Consistent with inhibition of cytoplasmic protein kinase reported previously (Kaser et at., 1980), the uptake of [32P]Pi into proteins in the ribonucleoprotein particles was also diminished.

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Modification of rat liver RNA polymerase I after in vivo stimulation by hydrocortisone or methylisobutylxanthine

Journal of Biological Chemistry ◽

10.1016/s0021-9258(17)30416-7 ◽

1978 ◽

Vol 253 (13) ◽

pp. 4514-4516

Author(s):

J.A. Todhunter ◽

H. Weissbach ◽

N. Brot

Keyword(s):

Rna Polymerase ◽

Rat Liver ◽

Rna Polymerase I ◽

Polymerase I

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The effects of salicylate on the activity of rat liver tyrosine–2-oxoglutarate aminotransferase in vitro and in vivo

Biochemical Journal ◽

10.1042/bj1260347 ◽

1972 ◽

Vol 126 (2) ◽

pp. 347-350 ◽

Cited By ~ 2

Author(s):

A. A.-B. Badawy

Keyword(s):

Rat Liver ◽

Pyridoxal Phosphate ◽

Actinomycin D ◽

Sodium Salicylate ◽

Intraperitoneal Administration ◽

Tyrosine Aminotransferase ◽

Major Effect ◽

Endogenous Activity

1. Salicylate, in concentrations of 0.25mm and above, enhances the basal activity of tyrosine–2-oxoglutarate aminotransferase in homogenates of rat liver incubated in the absence of added pyridoxal 5′-phosphate (endogenous activity). The effect is decreased by increasing the concentration of the cofactor. 2. The intraperitoneal administration of sodium salicylate enhances the activity of rat liver tyrosine aminotransferase; the major effect during the first hour being on the enzyme in the absence of added pyridoxal phosphate. Actinomycin D prevents the induction of the enzyme by cortisol and tryptophan. Induction by pyridoxine or salicylate is 50% inhibited by actinomycin D. The effects of the injections of various combinations of cortisol, pyridoxine and salicylate were also studied in the absence or presence of actinomycin D. 3. It is suggested that salicylate induces rat liver tyrosine aminotransferase by displacing its protein-bound cofactor and that a cofactor-type induction of the hepatic enzyme occurs in pyridoxine-treated rats.

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Stimulation of the mouse rRNA gene promoter by a distal spacer promoter.

Molecular and Cellular Biology ◽

10.1128/mcb.15.8.4648 ◽

1995 ◽

Vol 15 (8) ◽

pp. 4648-4656 ◽

Cited By ~ 14

Author(s):

M H Paalman ◽

S L Henderson ◽

B Sollner-Webb

Keyword(s):

Rna Polymerase ◽

Gene Promoter ◽

Rna Polymerase I ◽

Rrna Gene ◽

Transcriptional Terminator ◽

Wide Range ◽

Polymerase I ◽

Enhancer Sequences ◽

Stimulation Of

We show that the mouse ribosomal DNA (rDNA) spacer promoter acts in vivo to stimulate transcription from a downstream rRNA gene promoter. This augmentation of mammalian RNA polymerase I transcription is observed in transient-transfection experiments with three different rodent cell lines, under noncompetitive as well as competitive transcription conditions, over a wide range of template concentrations, whether or not the enhancer repeats alone stimulate or repress expression from the downstream gene promoter. Stimulation of gene promoter transcription by the spacer promoter requires the rDNA enhancer sequences to be present between the spacer promoter and gene promoter and to be oriented as in native rDNA. Stimulation also requires that the spacer promoter be oriented toward the enhancer and gene promoter. However, stimulation does not correlate with transcription from the spacer promoter because the level of stimulation is not altered by either insertion of a functional mouse RNA polymerase I transcriptional terminator between the spacer promoter and enhancer or replacement with a much more active heterologous polymerase I promoter. Further analysis with a series of mutated spacer promoters indicates that the stimulatory activity does not reside in the major promoter domains but requires the central region of the promoter that has been correlated with enhancer responsiveness in vivo.

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Inactivation of tyrosine aminotransferase in neutral homogenates and rat liver slices

Biochemical Journal ◽

10.1042/bj1291131 ◽

1972 ◽

Vol 129 (5) ◽

pp. 1131-1138 ◽

Cited By ~ 20

Author(s):

F. Auricchio ◽

L. Mollica ◽

A. Liguori

Keyword(s):

Amino Acid ◽

Rat Liver ◽

Acid Concentration ◽

Tyrosine Aminotransferase ◽

Amino Acid Concentration ◽

Acidic Ph ◽

Ph Values ◽

Neutral Ph ◽

Liver Slices

Inactivation of tyrosine aminotransferase induced in vivo by triamcinolone was studied in a homogenate incubated at neutral pH values. The integrity and the presence of subcellular particles together with a compartment of acidic pH are necessary for inactivation of tyrosine aminotransferase. It is suggested that tyrosine aminotransferase is inactivated inside lysosomes. The system responsible for inactivation of tyrosine aminotransferase was partially purified and identified with lysosomal cathepsins B and B1. Inactivation of tyrosine aminotransferase in liver slices is controlled by the amino acid concentration and strongly stimulated by cysteine. 3,3′,5-Tri-iodo-l-thyronine reversibly and strongly decreases the rate of inactivation of tyrosine aminotransferase. The effect is not due to an increased rate of tyrosine aminotransferase synthesis.

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Erythropoiesis in steel mutant mice: effects of erythropoietin in vitro

Blood ◽

10.1182/blood.v45.3.427.427 ◽

1975 ◽

Vol 45 (3) ◽

pp. 427-433 ◽

Cited By ~ 5

Author(s):

DH Chui ◽

BV Loyer

Keyword(s):

Culture System ◽

Marrow Cell ◽

Biologically Active ◽

Mutant Mice ◽

Erythroid Cell ◽

Biochemical Modification ◽

Normochromic Anemia ◽

Stimulation Of

Abstract Adult SI/SI-d mutant mice have severe macrocytic, normochromic anemia. Moreover these animals are unresponsive to the stimulation of erythropoietin in vivo. By means of a bone marrow cell suspension culture system, the present investigation shows that in adult SI/SI-d marrow, there are cells capable of responding in vitro to erythropoietin in a normal fashion. Moreover, the erythropoietin present in SI/SI-d serum is biologically active in vitro without any prior biochemical modification. These observations support the suggestion that there is a defect in differentiation in the erythroid cell lines of SI/SI-d mice in vivo due to an abnormal hemopoietic microenvironment.

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Biotin-mediated protein biosynthesis

Biochemical Journal ◽

10.1042/bj1400549 ◽

1974 ◽

Vol 140 (3) ◽

pp. 549-556 ◽

Cited By ~ 24

Author(s):

R. L. Boeckx ◽

K. Dakshinamurti

Keyword(s):

Protein Synthesis ◽

Amino Acid ◽

Rat Liver ◽

Intestinal Mucosa ◽

Protein Biosynthesis ◽

Amino Acid Incorporation ◽

Acid Incorporation ◽

Stimulation Of

The effect of administration of biotin to biotin-deficient rats on protein biosynthesis was studied. Biotin treatment resulted in stimulation by more than twofold of amino acid incorporation into protein, both in vivo and in vitro in rat liver, pancreas, intestinal mucosa and skin. Analysis of the products of amino acid incorporation into liver proteins in vivo and in vitro indicated that the synthesis of some proteins was stimulated more than twofold, but others were not stimulated at all. This indicates a specificity in the stimulation of protein synthesis mediated by biotin.

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Genetic interaction mapping informs integrative structure determination of protein complexes

Science ◽

10.1126/science.aaz4910 ◽

2020 ◽

Vol 370 (6522) ◽

pp. eaaz4910 ◽

Cited By ~ 1

Author(s):

Hannes Braberg ◽

Ignacia Echeverria ◽

Stefan Bohn ◽

Peter Cimermancic ◽

Anthony Shiver ◽

...

Keyword(s):

Rna Polymerase ◽

Rna Polymerase Ii ◽

Structure Determination ◽

Genetic Interaction ◽

Protein Complexes ◽

Point Mutations ◽

Genetic Interactions ◽

Cellular Functions ◽

Cross Links

Determining structures of protein complexes is crucial for understanding cellular functions. Here, we describe an integrative structure determination approach that relies on in vivo measurements of genetic interactions. We construct phenotypic profiles for point mutations crossed against gene deletions or exposed to environmental perturbations, followed by converting similarities between two profiles into an upper bound on the distance between the mutated residues. We determine the structure of the yeast histone H3-H4 complex based on ~500,000 genetic interactions of 350 mutants. We then apply the method to subunits Rpb1-Rpb2 of yeast RNA polymerase II and subunits RpoB-RpoC of bacterial RNA polymerase. The accuracy is comparable to that based on chemical cross-links; using restraints from both genetic interactions and cross-links further improves model accuracy and precision. The approach provides an efficient means to augment integrative structure determination with in vivo observations.

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