Zones of No Activation

2009 ◽  
pp. 189-205
Author(s):  
Vadrevu Sree Hari Rao ◽  
Ponnada Raja Sekhara Rao
Keyword(s):  
No Activation

scholarly journals Integrin-mediated Activation of Focal Adhesion Kinase Is Required for Signaling to Jun NH2-terminal Kinase and Progression through the G1 Phase of the Cell Cycle

1999 ◽  
Vol 145 (7) ◽  
pp. 1461-1470 ◽  
Author(s):  
Maja Oktay ◽  
Kishore K. Wary ◽  
Michael Dans ◽  
Raymond B. Birge ◽  
Filippo G. Giancotti
Keyword(s):  
Cell Cycle ◽  
Focal Adhesion Kinase ◽  
Focal Adhesion ◽  
G1 Phase ◽  
Normal Cells ◽  
Jnk Signaling ◽  
Stringent Control ◽  
No Activation ◽  
Stimulation Of

The extracellular matrix exerts a stringent control on the proliferation of normal cells, suggesting the existence of a mitogenic signaling pathway activated by integrins, but not significantly by growth factor receptors. Herein, we provide evidence that integrins cause a significant and protracted activation of Jun NH2-terminal kinase (JNK), while several growth factors cause more modest or no activation of this enzyme. Integrin-mediated stimulation of JNK required the association of focal adhesion kinase (FAK) with a Src kinase and p130CAS, the phosphorylation of p130CAS, and subsequently, the recruitment of Crk. Ras and PI-3K were not required. FAK–JNK signaling was necessary for proper progression through the G1 phase of the cell cycle. These findings establish a role for FAK in both the activation of JNK and the control of the cell cycle, and identify a physiological stimulus for JNK signaling that is consistent with the role of Jun in both proliferation and transformation.

scholarly journals Butyl Isocyanide as a Probe of the Activation Mechanism of Soluble Guanylate Cyclase

2007 ◽  
Vol 282 (49) ◽  
pp. 35741-35748 ◽  
Author(s):  
Emily R. Derbyshire ◽  
Michael A. Marletta
Keyword(s):  
Nitric Oxide ◽  
Binding Site ◽  
Guanylate Cyclase ◽  
Electronic Absorption ◽  
Soluble Guanylate Cyclase ◽  
Activation Mechanism ◽  
Activation Process ◽  
Absorbance Maximum ◽  
No Activation ◽  
Allosteric Activator

Nitric oxide (NO) is a physiologically relevant activator of the hemoprotein soluble guanylate cyclase (sGC). In the presence of NO, sGC is activated several hundredfold above the basal level by a mechanism that remains to be elucidated. The heme ligand n-butyl isocyanide (BIC) was used to probe the mechanism of NO activation of sGC. Electronic absorption spectroscopy was used to show that BIC binds to the sGC heme, forming a 6-coordinate complex with an absorbance maximum at 429 nm. BIC activates sGC 2-5-fold, and synergizes with the allosteric activator YC-1, to activate the enzyme 15-25-fold. YC-1 activates the sGC-BIC complex, and leads to an increase in both the Vmax and Km. BIC was also used to probe the mechanism of NO activation. The activity of the sGC-BIC complex increases 15-fold in the presence of NO, without displacing BIC at the heme, which is consistent with previous reports that proposed the involvement of a non-heme NO binding site in the activation process.

Suppression of chromosome condensation during meiotic maturation induces parthenogenetic development of mouse oocytes

Development ◽  
1988 ◽  
Vol 104 (1) ◽  
pp. 97-103 ◽  
Author(s):  
H.J. Clarke ◽  
J. Rossant ◽  
Y. Masui
Keyword(s):  
Protein Synthesis ◽  
Blastocyst Stage ◽  
Chromosome Condensation ◽  
Meiotic Maturation ◽  
Dibutyryl Cyclic Amp ◽  
Developmental Arrest ◽  
Mouse Oocytes ◽  
Parthenogenetic Development ◽  
No Activation ◽  
Metaphase I

Mouse oocytes at metaphase I were treated with puromycin, which caused the chromosomes to become decondensed within an interphase nucleus. When the oocytes were allowed to resume protein synthesis, they returned to metaphase within 8–10 h and neither synthesized DNA nor cleaved, indicating that they had not been parthenogenetically activated by the puromycin treatment. However, when dibutyryl cyclic AMP was added to the medium after protein synthesis resumed, the oocytes remained in interphase. These oocytes maintained in interphase began DNA synthesis beginning 20 h after puromycin withdrawal, even though no activation stimulus had been given to them. After transfer to the oviducts of foster mothers, the oocytes could develop to the blastocyst stage. These results indicate that oocytes whose chromosomes were decondensed by puromycin treatment at metaphase I could begin parthenogenetic development in the absence of an activating stimulus, provided that they were prevented from returning to metaphase. In contrast, when the puromycin-treated oocytes were allowed to return to metaphase, they became developmentally arrested at the end of maturation. This suggests that the mechanism responsible for the developmental arrest of mature oocytes at metaphase II depends on cytoplasmic conditions that cause chromosome condensation to the metaphase state.

CircRNA circ-0110102 Function as Anti-oncogenic Gene in Hepatocellular Carcinoma through Modulating miR-580-5p/CCL2 Pathway

2020 ◽  
Author(s):  
Xinxing Wang ◽  
Wei Sheng ◽  
Tao Xu ◽  
Jiawen Xu ◽  
Juntao Chen ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Molecular Mechanisms ◽  
Tumor Biology ◽  
Luciferase Assay ◽  
Migration And Invasion ◽  
Circular Rnas ◽  
Dependent Manner ◽  
Activation Effect ◽  
Cox 2 ◽  
No Activation

Abstract Background Circular RNAs (circRNAs) have been shown to have critical regulatory roles in tumor biology, whereas their contributions in hepatocellular carcinoma (HCC) still remains enigmatic. The purpose of this study was to investigate the molecular mechanisms involved in hsa_circ_0110102 in the occurrence and development of HCC. Results hsa_circ_0110102 was significantly down-regulated in HCC cell lines and tissues, low hsa_circ_0110102 expression levels were associated with poor prognosis. Knockdown hsa_circ_0110102 significantly inhibited cell proliferation, migration and invasion. In addition, the interaction between hsa_circ_0110102 and miR-580-5p was predicted and verified by luciferase assay and RNA pull-down, indicating that hsa_circ_0110102 function as sponge of miR-580-5p. Moreover, miR-580-5p which could directly bind to the 3’-UTR of CCL2 and induce its expression, then active the COX-2/PGE2 pathway in macrophage via FoxO1 in p38 MAPK dependent manner. Furthermore, the Δ256 mutant of FoxO1 showed no activation effect. These results concluded that hsa_circ_0110102 act as a sponge for miR-580-5p and decreased CCL2 secretion in HCC cells, then inhibits pro-inflammatory cytokine release from activated macrophage by regulating the COX-2/PGE2 pathway. Conclusions These results indicating that hsa_circ_0110102 serves as a potential prognostic predictor or therapeutic target for HCC.

Carbohydrate metabolism and its response to catecholamines as modified in alkalotic rat

1975 ◽  
Vol 228 (4) ◽  
pp. 1046-1052 ◽  
Author(s):  
M Yajima ◽  
M Ui
Keyword(s):  
Insulin Secretion ◽  
Blood Glucose ◽  
Carbohydrate Metabolism ◽  
Skeletal Muscles ◽  
Glycolytic Pathway ◽  
Glyceric Acid ◽  
Glucose Load ◽  
Metabolic Activities ◽  
No Activation ◽  
Fasted Rats

Metabolic activities and their responses to catecholamines were studied in fasted rats exposed to simulated altitudes. Analysis of hepatic levels of gluconeogenic intermediates revealed the inhibition of gluconeogenesis between glyceric acid 3-P and fructose 6-P associated with a rise of the ratios of redox pairs such as lactate to pyruvate in livers of alkalotic rats. Inhibition of gluconeogenesis was indicated also by the suppressed incorporation of glutamate 14C into blood glucose. Since no activation was detected on glycolytic pathway of skeletal muscles, marked hyperlactacidemia during alkalosis appeared to result from the suppression of hepatic gluconeogenesis. Most of metabolic actions of epinephrine and isoproterenal known to be mediated via the beta receptor were significantly reduced but not completely abolished during alkalosis. Exceptionally, hyperinsulinemia induced by isoproterenol was completely reversed and replaced by hypoinsulinemia during alkalosis. Despite hypoinsulinemia, hyperglycemia induced by glucose load decreased more rapidly in alkalotic than in normal rats. In view of the fact that the adrenergic alpha receptor is involved in theinhibition of insulin secretion, the observed irregular modifications of catecholamine actions could be explained on the basis of a postulate that the adrenergic alpha-receptor functions are potentiated in alkalosis.

scholarly journals Activation of JNK in rat heart by exercise: effect of training

2003 ◽  
Vol 285 (6) ◽  
pp. H2639-H2647 ◽  
Author(s):  
M. O. Boluyt ◽  
A. M. Loyd ◽  
M. H. Roth ◽  
M. J. Randall ◽  
E. Y. M. Song
Keyword(s):  
High Intensity ◽  
Rat Heart ◽  
Dependent Manner ◽  
High Intensity Training ◽  
Long Duration ◽  
Single Bout ◽  
Exercise Effect ◽  
No Activation ◽  
Intensity Training ◽  
Training Protocol

The purpose of the study was to determine whether exercise would activate JNK in the heart and whether chronic exercise training would alter the response. Untrained rats were familiarized with the treadmill and assigned to one of four groups: low intensity (LI), 10 min, 0%, 15 m/min; medium intensity (MI), 10 min, 0%, 33 m/min; high intensity (HI), 10 min, 25%, 33 m/min; long duration (LD), 30 min, 0%, 15 m/min. Another cohort of rats was subjected to a progressive 6 wk high-intensity training protocol that produced a 12% increase in heart mass. In untrained rats, JNK activity was LI: 1.5 (fold nonrun control), MI: 2.0, HI: 2.5, LD: 1.25 immediately after a single bout of exercise. In trained rats, no activation of JNK above baseline was detected after either a 10-min or 1-h bout of exercise. We concluded that treadmill exercise activates JNK in the rat heart in an intensity-dependent manner and that chronic training abrogates the myocardial JNK response to a bout of exercise.

Hydrogenated polycyclic aromatic hydrocarbons (HnPAHs) as catalysts for hydrogenation reactions in the interstellar medium: a quantum chemical model

2019 ◽  
Vol 21 (22) ◽  
pp. 12012-12020 ◽  
Author(s):  
Ricardo M. Ferullo ◽  
Carolina E. Zubieta ◽  
Patricia G. Belelli
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Quantum Chemical ◽  
Density Functional ◽  
Activation Barrier ◽  
Functional Studies ◽  
Quantum Chemical Model ◽  
Polycyclic Aromatic ◽  
Hydrogenation Reactions ◽  
No Activation

Density functional studies show that neutral HnPAHs are able to catalyze the formation of water with no activation barrier.

scholarly journals Defective activation by glucose of hepatic glycogen synthesis in the obese hyperglycaemic mouse

1983 ◽  
Vol 216 (2) ◽  
pp. 491-494 ◽  
Author(s):  
S A Smith ◽  
M A Cawthorne ◽  
A L Levy ◽  
D L Simson
Keyword(s):  
Glycogen Synthase ◽  
Glycogen Synthesis ◽  
Fold Increase ◽  
Hepatic Glycogen ◽  
Oral Glucose ◽  
Oral Glucose Load ◽  
Glucose Load ◽  
No Activation ◽  
Sustained Activation

The administration of an oral glucose load to 24 h-starved lean (+/?) male C57BL/6 mice produced a rapid, 7-fold increase in the rate of hepatic glycogen synthesis and a sustained activation of glycogen synthase. In contrast, glucose produced only a small (4.5-fold), short-lived increase in hepatic glycogen synthesis in genetically obese (ob/ob) mice and no activation of glycogen synthase.

scholarly journals Differential regulation of Ca2+/calmodulin-dependent enzymes by plant calmodulin isoforms and free Ca2+ concentration

2000 ◽  
Vol 350 (1) ◽  
pp. 299-306 ◽  
Author(s):  
Sang Hyoung LEE ◽  
J. David JOHNSON ◽  
Michael P. WALSH ◽  
Jacquelyn E. VAN LIEROP ◽  
Cindy SUTHERLAND ◽  
...  
Keyword(s):  
Myosin Light Chain ◽  
Fold Increase ◽  
Differential Regulation ◽  
Enzyme Activation ◽  
Soya Bean ◽  
Dependent Protein Kinase ◽  
Maximal Activation ◽  
Dependent Protein ◽  
No Activation ◽  
Target Enzyme

Multiple calmodulin (CaM) isoforms are expressed in plants, but their biochemical characteristics are not well resolved. Here we show the differential regulation exhibited by two soya bean CaM isoforms (SCaM-1 and SCaM-4) for the activation of five CaM-dependent enzymes, and the Ca2+ dependence of their target enzyme activation. SCaM-1 activated myosin light-chain kinase as effectively as brain CaM (Kact 1.8 and 1.7nM respectively), but SCaM-4 produced no activation of this enzyme. Both CaM isoforms supported near maximal activation of CaM-dependent protein kinase II (CaM KII), but SCaM-4 exhibited approx.12-fold higher Kact than SCaM-1 for CaM KII phosphorylation of caldesmon. The SCaM isoforms showed differential activation of plant and animal Ca2+-ATPases. The plant Ca2+-ATPase was activated maximally by both isoforms, while the erythrocyte Ca2+-ATPase was activated only by SCaM-1. Plant glutamate decarboxylase was activated fully by SCaM-1, but SCaM-4 exhibited an approx. 4-fold increase in Kact and an approx. 25% reduction in Vmax. Importantly, SCaM isoforms showed a distinct Ca2+ concentration requirement for target enzyme activation. SCaM-4 required 4-fold higher [Ca2+] for half-maximal activation of CaM KII, and 1.5-fold higher [Ca2+] for activation of cyclic nucleotide phosphodiesterase than SCaM-1. Thus these plant CaM isoforms provide a mechanism by which a different subset of target enzymes could be activated or inhibited by the differential expression of these CaM isoforms or by differences in Ca2+ transients.

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