The effect of triiodothyronine on cyclic AMP, phosphorylase, and adenyl cyclase in rat heart

1969 ◽  
Vol 47 (11) ◽  
pp. 913-916 ◽  
Author(s):  
John H. McNeill ◽  
Lawrence D. Muschek ◽  
Theodore M. Brody
Keyword(s):  
Thyroid Hormone ◽  
Cyclic Amp ◽  
Rat Heart ◽  
Adenyl Cyclase

Pretreatment with triiodothyronine (T3) greatly enhanced the epinephrine-induced increase in rat cardiac phosphorylase a. T3 treatment, however, did not increase the level of adenosine-3′,5′-monophosphate (cyclic AMP) in rat heart. T3 treatment also did not increase the activity of rat heart adenyl cyclase or change the sensitivity of the enzyme to epinephrine when activity was determined in vitro. It is suggested that if thyroid hormone affects the activity of adenyl cyclase in vivo the effect is lost in the preparation of the enzyme for assay in vitro.

scholarly journals Thyroid hormone increases beta‐catenin levels through PI3K in rat heart in vivo and in vitro

2008 ◽  
Vol 22 (S1) ◽  
Author(s):  
Marcela Sorelli Carneiro‐Ramos ◽  
Gabriela Placoná Diniz ◽  
Maria Luiza Morais Barreto‐Chaves ◽  
Anselmo Sigari Moriscot
Keyword(s):  
Thyroid Hormone ◽  
Rat Heart ◽  
Beta Catenin

scholarly journals Selective labelling and inactivation of creatine kinase isoenzymes by the thyroid hormone derivative N-bromoacetyl-3,3′,5-tri-iodo-l-thyronine

1993 ◽  
Vol 291 (2) ◽  
pp. 463-472 ◽  
Author(s):  
M Wyss ◽  
T Wallimann ◽  
J Köhrle
Keyword(s):  
Creatine Kinase ◽  
Thyroid Hormone ◽  
Thyroid Hormones ◽  
Rat Heart ◽  
Covalent Modification ◽  
Regulation Of Transcription ◽  
Selective Labelling ◽  
Mitochondrial Fractions

Besides their well-known regulation of transcription by binding to nuclear receptors, thyroid hormones have been suggested to have direct effects on mitochondria. In a previous study, incubation of rat heart mitochondria with 125I-labelled N-bromoacetyl-3,3′,5-tri-iodo-L-thyronine (BrAcT3), a thyroid hormone derivative with an alkylating side chain, resulted in the selective labelling of a protein doublet around M(r) 45,000 on SDS/polyacrylamide gels [Rasmussen, Köhrle, Rokos and Hesch (1989) FEBS Lett. 255, 385-390]. Now, this protein doublet has been identified as mitochondrial creatine kinase (Mi-CK). Immunoblotting experiments with the cytoplasmic and mitochondrial fractions of rat heart, brain and liver, as well as inactivation studies with the purified chicken CK isoenzymes have further demonstrated that all four CK isoenzymes (Mia-, Mib-, M- and B-CK) are indeed selectively labelled by BrAcT3. However, in contrast with their bromoalkyl derivatives, thyroid hormones themselves did not compete for CK labelling, suggesting that not the thyroid hormone moiety but rather the bromoacetyl-driven alkylation of the highly reactive ‘essential’ thiol group of CK accounts for this selective labelling. Therefore the assumption that CK isoenzymes are thyroid-hormone-binding proteins has to be dismissed. Instead, bromoacetyl-based reagents may allow a very specific covalent modification and inactivation of CK isoenzymes in vitro and in vivo.

scholarly journals Influence of thyroid hormone on the in vitro translational activity of specific mRNAs in the rat heart.

1983 ◽  
Vol 258 (12) ◽  
pp. 7738-7745 ◽  
Author(s):  
W H Dillmann ◽  
A Barrieux ◽  
W E Neeley ◽  
P Contreras
Keyword(s):  
Thyroid Hormone ◽  
Rat Heart ◽  
Translational Activity ◽  
Specific Mrnas

Transcription from a murine T-cell receptor V beta promoter depends on a conserved decamer motif similar to the cyclic AMP response element

1989 ◽  
Vol 9 (11) ◽  
pp. 4835-4845
Author(s):  
S J Anderson ◽  
S Miyake ◽  
D Y Loh
Keyword(s):  
Cyclic Amp ◽  
Regulatory Region ◽  
Cell Receptor ◽  
Transcription Activator ◽  
Mobility Shift ◽  
Response Element ◽  
Cyclic Amp Response Element ◽  
Gel Mobility Shift

We identified a regulatory region of the murine V beta promoter by both in vivo and in vitro analyses. The results of transient transfection assays indicated that the dominant transcription-activating element within the V beta 8.3 promoter is the palindromic motif identified previously as the conserved V beta decamer. Elimination of this element, by linear deletion or specific mutation, reduced transcriptional activity from this promoter by 10-fold. DNase I footprinting, gel mobility shift, and methylation interference assays confirmed that the palindrome acts as the binding site of a specific nuclear factor. In particular, the V beta promoter motif functioned in vitro as a high-affinity site for a previously characterized transcription activator, ATF. A consensus cyclic AMP response element (CRE) but not a consensus AP-1 site, can substitute for the decamer in vivo. These data suggest that cyclic AMP response element-binding protein (ATF/CREB) or related proteins activate V beta transcription.

ADR1c mutations enhance the ability of ADR1 to activate transcription by a mechanism that is independent of effects on cyclic AMP-dependent protein kinase phosphorylation of Ser-230

1992 ◽  
Vol 12 (4) ◽  
pp. 1507-1514
Author(s):  
C L Denis ◽  
S C Fontaine ◽  
D Chase ◽  
B E Kemp ◽  
L T Bemis
Keyword(s):  
Protein Kinase ◽  
Cyclic Amp ◽  
Transcriptional Activation ◽  
Growth Conditions ◽  
Dependent Protein Kinase ◽  
Inactive Form ◽  
Dependent Protein ◽  
Kinase Phosphorylation

Four ADR1c mutations that occur close to Ser-230 of the Saccharomyces cerevisiae transcriptional activator ADR1 and which greatly enhance the ability of ADR1 to activate ADH2 expression under glucose-repressed conditions have been shown to reduce or eliminate cyclic AMP-dependent protein kinase (cAPK) phosphorylation of Ser-230 in vitro. In addition, unregulated cAPK expression in vivo blocks ADH2 depression in an ADR1-dependent fashion in which ADR1c mutations display decreased sensitivity to unregulated cAPK activity. Taken together, these data have suggested that ADR1c mutations enhance ADR1 activity by blocking cAPK phosphorylation and inactivation of Ser-230. We have isolated and characterized an additional 17 ADR1c mutations, defining 10 different amino acid changes, that were located in the region defined by amino acids 227 through 239 of ADR1. Three observations, however, indicate that the ADR1c phenotype is not simply equivalent to a lack of cAPK phosphorylation. First, only some of these newly isolated ADR1c mutations affected the ability of yeast cAPK to phosphorylate corresponding synthetic peptides modeled on the 222 to 234 region of ADR1 in vitro. Second, we observed that strains lacking cAPK activity did not display enhanced ADH2 expression under glucose growth conditions. Third, when Ser-230 was mutated to a nonphosphorylatable residue, lack of cAPK activity led to a substantial increase in ADH2 expression under glucose-repressed conditions. Thus, while cAPK controls ADH2 expression and ADR1 is required for this control, cAPK acts by a mechanism that is independent of effects on ADR1 Ser-230. It was also observed that deletion of the ADR1c region resulted in an ADR1c phenotype. The ADR1c region is, therefore, involved in maintaining ADR1 in an inactive form. ADR1c mutations may block the binding of a repressor to ADR1 or alter the structure of ADR1 so that transcriptional activation regions become unmasked.

Reduced high-energy phosphate levels in rat hearts. I. Effects of alloxan diabetes

1976 ◽  
Vol 230 (6) ◽  
pp. 1744-1750 ◽  
Author(s):  
TB Allison ◽  
SP Bruttig ◽  
Crass MF ◽  
RS Eliot ◽  
JC Shipp
Keyword(s):  
Oxidative Metabolism ◽  
Oxygen Delivery ◽  
Rat Heart ◽  
High Energy ◽  
Diabetic Rat ◽  
High Energy Phosphate ◽  
Atp Production ◽  
Rat Hearts

Significant alterations in heart carbohydrate and lipid metabolism are present 48 h after intravenous injection of alloxan (60 mg/kg) in rats. It has been suggested that uncoupling of oxidative phosphorylation occurs in the alloxanized rat heart in vivo, whereas normal oxidative metabolism has been demonstrated in alloxan-diabetic rat hearts perfused in vitro under conditions of adequate oxygen delivery. We examined the hypothesis that high-energy phosphate metabolism might be adversely affected in the alloxan-diabetic rat heart in vivo. Phosphocreatine and ATP were reduced by 58 and 45%, respectively (P is less than 0.001). Also, oxygen-dissociation curves were shifted to the left by 4 mmHg, and the rate of oxygen release from blood was reduced by 21% (P is less than 0.01). Insulin administration normalized heart high-energy phosphate compounds. ATP production was accelerated in diabetic hearts perfused in vitro with a well-oxygenated buffer. These studies support the hypothesis that oxidative ATP production in the alloxan-diabetic rat heart is reduced and suggest that decreased oxygen delivery may have a regulatory role in the oxidative metabolism of the diabetic rat heart.

scholarly journals Cyclic AMP-dependent protein kinase inhibits the activity of myogenic helix-loop-helix proteins.

1992 ◽  
Vol 12 (10) ◽  
pp. 4478-4485 ◽  
Author(s):  
L Li ◽  
R Heller-Harrison ◽  
M Czech ◽  
E N Olson
Keyword(s):  
Protein Kinase ◽  
Cyclic Amp ◽  
Transcriptional Activation ◽  
Consensus Sequence ◽  
Signal Transduction Pathway ◽  
Specific Gene ◽  
Dependent Protein Kinase ◽  
Dependent Protein

Differentiation of skeletal muscle cells is inhibited by the cyclic AMP (cAMP) signal transduction pathway. Here we report that the catalytic subunit of cAMP-dependent protein kinase (PKA) can substitute for cAMP and suppress muscle-specific transcription by silencing the activity of the MyoD family of regulatory factors, which includes MyoD, myogenin, myf5, and MRF4. Repression by the PKA catalytic (C) subunit is directed at the consensus sequence CANNTG, the target for DNA binding and transcriptional activation by these myogenic regulators. Phosphopeptide mapping of myogenin in vitro and in vivo revealed two PKA phosphorylation sites, both within the basic region. However, repression of myogenin function by PKA does not require direct phosphorylation of these sites but instead involves an indirect mechanism with one or more intermediate steps. Regulation of the transcriptional activity of the MyoD family by modulation of the cAMP signaling pathway may account for the inhibitory effects of certain peptide growth factors on muscle-specific gene expression and may also determine the responsiveness of different cell types to myogenic conversion by these myogenic regulators.

Cannabinoid effects on adenylate cyclase and phosphodiesterase activities of mouse brain

1977 ◽  
Vol 55 (4) ◽  
pp. 934-942 ◽  
Author(s):  
Thomas W. Dolby ◽  
Lewis J. Kleinsmith
Keyword(s):  
Cyclic Amp ◽  
Adenylate Cyclase ◽  
Mouse Brain ◽  
Biogenic Amine ◽  
Specific Activity ◽  
Intraperitoneal Administration ◽  
The Brain

The experiments presented in this paper examine the mechanisms underlying the ability of cannabinoids to alter the in vivo levels of cyclic adenosine 3′,5′-monophosphate (cyclic AMP) in mouse brain. It was found that changes in cyclic AMP levels are a composite result of direct actions of cannabinoids on adenylate cyclase (EC 4.6.1.1) activity and indirect actions involving the potentiation or inhibition of biogenic amine induced activity of adenylate cyclase. Furthermore, the long-term intraperitoneal administration of 1-(−)-Δ-tetrahydrocannabinol to mice produced a form of phosphodiesterase (EC 3.1.4.17) in the brain whose activity is not stimulated by Ca2+, although its basal specific activity is similar to that of control animals. In vitro, the presence of the cannabinoids caused no significant changes in activity of brain PDE at the concentrations tested. Some correlations are presented which imply that many of the observed behavioral and physiological actions of the cannabinoids in mammalian organisms may be mediated via cyclic AMP mechanisms.

Cyclic AMP-dependent protein kinase inhibits the activity of myogenic helix-loop-helix proteins

1992 ◽  
Vol 12 (10) ◽  
pp. 4478-4485
Author(s):  
L Li ◽  
R Heller-Harrison ◽  
M Czech ◽  
E N Olson
Keyword(s):  
Protein Kinase ◽  
Cyclic Amp ◽  
Transcriptional Activation ◽  
Consensus Sequence ◽  
Signal Transduction Pathway ◽  
Specific Gene ◽  
Dependent Protein Kinase ◽  
Dependent Protein

Differentiation of skeletal muscle cells is inhibited by the cyclic AMP (cAMP) signal transduction pathway. Here we report that the catalytic subunit of cAMP-dependent protein kinase (PKA) can substitute for cAMP and suppress muscle-specific transcription by silencing the activity of the MyoD family of regulatory factors, which includes MyoD, myogenin, myf5, and MRF4. Repression by the PKA catalytic (C) subunit is directed at the consensus sequence CANNTG, the target for DNA binding and transcriptional activation by these myogenic regulators. Phosphopeptide mapping of myogenin in vitro and in vivo revealed two PKA phosphorylation sites, both within the basic region. However, repression of myogenin function by PKA does not require direct phosphorylation of these sites but instead involves an indirect mechanism with one or more intermediate steps. Regulation of the transcriptional activity of the MyoD family by modulation of the cAMP signaling pathway may account for the inhibitory effects of certain peptide growth factors on muscle-specific gene expression and may also determine the responsiveness of different cell types to myogenic conversion by these myogenic regulators.

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