scholarly journals State-Selective Frustration as a Key Driver of Allosteric Pluripotency

2021 ◽  
Author(s):  
Jung Ah Byun ◽  
Bryan VanSchouwen ◽  
Nishi Parikh ◽  
Madoka Akimoto ◽  
Eric Tyler McNicholl ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Protein Kinase A ◽  
Experimental Conditions ◽  
Allosteric Effector ◽  
Key Driver ◽  
Kinase A

Allosteric pluripotency arises when an allosteric effector switches from agonist to antagonist depending on the experimental conditions. For example, the Rp-cAMPS ligand of Protein Kinase A (PKA) switches from agonist...

scholarly journals ATP stimulates lysosomal sulphate transport at neutral pH: evidence for phosphorylation of the lysosomal sulphate carrier

1997 ◽  
Vol 327 (3) ◽  
pp. 781-786 ◽  
Author(s):  
Hsu-Fang CHOU ◽  
Merry PASSAGE ◽  
J. Adam JONAS
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Protein Kinase A ◽  
Atp Hydrolysis ◽  
Experimental Conditions ◽  
Protein Kinase C Inhibitors ◽  
Sulphate Transport ◽  
Sulphate Uptake ◽  
Kinase C ◽  
Kinase A

ATP markedly stimulated sulphate uptake by rat liver lysosomes that had been treated with N-ethylmaleimide to block the effects of the lysosomal proton-translocating ATPase (H+-ATPase). Maximal stimulation required millimolar concentrations of ATP and neutral buffer pH. ATP-stimulated transport exhibited saturation kinetics with a Km of 175 μM, identical with the Km for lysosomal sulphate uptake at pH 5.0, a process that does not require ATP. The requirement for ATP was specific: other nucleotides such as AMP, ADP, CTP, GTP, ITP and UTP failed to stimulate transport. Adenosine 5ʹ-[β,γ-imido]triphosphate, the non-hydrolysable analogue of ATP, also failed to stimulate sulphate uptake, suggesting a requirement for ATP hydrolysis. Lysosomal pH, membrane potential and glucose transport were unchanged by the presence of ATP under the experimental conditions, consistent with a direct effect of ATP on the sulphate transporter. Exposure of lysosomes to protein kinase A and protein kinase C inhibitors did not alter the stimulation of sulphate transport by ATP. The lysosomal sulphate transport protein might be subject to regulation by a phosphorylation pathway that is not dependent on protein kinase A or protein kinase C.

Regulation of spontaneous and induced resumption of meiosis in mouse oocytes by different intracellular pathways

Reproduction ◽  
2000 ◽  
pp. 377-383 ◽  
Author(s):  
L Leonardsen ◽  
A Wiersma ◽  
M Baltsen ◽  
AG Byskov ◽  
CY Andersen
Keyword(s):  
Signal Transduction ◽  
Protein Kinase ◽  
Protein Kinase A ◽  
Mitogen Activated Protein Kinase ◽  
Meiotic Maturation ◽  
Mouse Oocytes ◽  
Mitogen Activated Protein ◽  
Dependent Signal ◽  
Kinase Pathway ◽  
Kinase A

The mitogen-activated protein kinase-dependent and the cAMP-protein kinase A-dependent signal transduction pathways were studied in cultured mouse oocytes during induced and spontaneous meiotic maturation. The role of the mitogen-activated protein kinase pathway was assessed using PD98059, which specifically inhibits mitogen-activated protein kinase 1 and 2 (that is, MEK1 and MEK2), which activates mitogen-activated protein kinase. The cAMP-dependent protein kinase was studied by treating oocytes with the protein kinase A inhibitor rp-cAMP. Inhibition of the mitogen-activated protein kinase pathway by PD98059 (25 micromol l(-1)) selectively inhibited the stimulatory effect on meiotic maturation by FSH and meiosis-activating sterol (that is, 4,4-dimethyl-5alpha-cholest-8,14, 24-triene-3beta-ol) in the presence of 4 mmol hypoxanthine l(-1), whereas spontaneous maturation in the absence of hypoxanthine was unaffected. This finding indicates that different signal transduction mechanisms are involved in induced and spontaneous maturation. The protein kinase A inhibitor rp-cAMP induced meiotic maturation in the presence of 4 mmol hypoxanthine l(-1), an effect that was additive to the maturation-promoting effect of FSH and meiosis-activating sterol, indicating that induced maturation also uses the cAMP-protein kinase A-dependent signal transduction pathway. In conclusion, induced and spontaneous maturation of mouse oocytes appear to use different signal transduction pathways.

Regulation of Hepatic Glucose Production by Transforming Growth Factor Beta 1 via Protein Kinase A

Diabetes ◽  
2018 ◽  
Vol 67 (Supplement 1) ◽  
pp. 2441-PUB ◽  
Author(s):  
QUAN PAN ◽  
YUNMEI CHEN ◽  
HUI YAN ◽  
WANBAO YANG ◽  
ZHENG SHEN ◽  
...  
Keyword(s):  
Growth Factor ◽  
Protein Kinase ◽  
Protein Kinase A ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Hepatic Glucose Production ◽  
Glucose Production ◽  
Hepatic Glucose ◽  
Growth Factor Beta ◽  
Kinase A
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