scholarly journals The requirement of guanine nucleotides for glucagon stimulation of adenylate cyclase in rat liver plasma membranes.

1977 ◽  
Vol 252 (11) ◽  
pp. 3829-3835 ◽  
Author(s):  
N Kimura ◽  
N Nagata
Keyword(s):  
Adenylate Cyclase ◽  
Rat Liver ◽  
Plasma Membranes ◽  
Guanine Nucleotides ◽  
Liver Plasma Membranes ◽  
Rat Liver Plasma Membranes ◽  
Stimulation Of

scholarly journals Effect of guanine nucleotides on polyphosphoinositide synthesis in rat liver plasma membranes

1990 ◽  
Vol 271 (3) ◽  
pp. 591-597 ◽  
Author(s):  
C Benistant ◽  
A P Thomas ◽  
R Rubin
Keyword(s):  
Rat Liver ◽  
Plasma Membranes ◽  
Atp Hydrolysis ◽  
Guanine Nucleotides ◽  
The Other ◽  
Gtp Binding ◽  
Liver Plasma Membranes ◽  
Rat Liver Plasma Membranes ◽  
Stimulation Of ◽  
Rapid Incorporation

The effect of guanosine 5′-[gamma-thio]triphosphate (GTP[S]) on PtdIns and PtdIns(4)P kinase activities was measured in rat liver plasma membranes. The addition of [32P]ATP resulted in the rapid incorporation of 32P into PtdIns(4)P and PtdIns(4,5)P2, with maximal levels reached within 30 s. GTP[S] (25-500 microM) increased the rate and magnitude of [32P]PtdIns(4)P and [32P]PtdIns(4,5)P2 formation by 50 and 120% respectively. Similar stimulatory effects were induced by guanosine 5′-[beta gamma-imido]triphosphate, GTP, GDP and guanosine 5′-[beta-thio]diphosphate. The stimulation of PtdIns phosphorylation by GTP[S] occurred in the presence of 2 mM-EGTA, a condition which fully inhibited phosphoinositide-specific phospholipase C. GTP[S] did not stimulate phosphomonoesterase activity, and its action was not due to the binding of magnesium. However, the overall ATP-hydrolysing activity of the membrane preparation was inhibited by GTP[S] and the other guanine nucleotides. There was a direct correlation between the extent of this inhibition and the stimulation of polyphosphoinositide formation. The results indicate that stimulation of polyphosphoinositide formation by guanine nucleotides in rat liver plasma membranes can be accounted for by an inhibition of ATP hydrolysis. These data are inconsistent with a specific GTP-binding protein (G-protein)-mediated stimulation of PtdIns or PtdIns(4)P kinase.

scholarly journals Lysophosphatidylcholines can modulate the activity of the glucagon-stimulated adenylate cyclase from rat liver plasma membranes

1979 ◽  
Vol 178 (1) ◽  
pp. 217-221 ◽  
Author(s):  
M D Houslay ◽  
R W Palmer
Keyword(s):  
Adenylate Cyclase ◽  
Rat Liver ◽  
Plasma Membranes ◽  
Hormone Receptors ◽  
Cyclase Activity ◽  
Adenylate Cyclase Activity ◽  
Liver Plasma Membranes ◽  
Rat Liver Plasma Membranes ◽  
Increased Sensitivity

1. Synthetic lysophosphatidylcholines inhibit the glucagon-stimulated adenylate cyclase activity of rat liver plasma membranes at concentrations two to five times lower than those needed to inhibit the fluoride-stimulated activity. 2. Specific 125I-labelled glucagon binding to hormone receptors is inhibited at concentrations similar to those inhibiting the fluoride-stimulated activity. 3. At concentrations of lysophosphatidylcholines immediately below those causing inhibition, an activation of adenylate cyclase activity or hormone binding was observed. 4 These effects are essentially reversible. 5. We conclude that the increased sensitivity of glucagon-stimulated adenylate cyclase to inhibition may be due to the lysophosphatidylcholines interfering with the physical coupling between the hormone receptor and catalytic unit of adenylate cyclase. 6. We suggest that, in vivo, it is possible that lysophosphatidylcholines may modulate the activity of adenylate cyclase only when it is in the hormone-stimulated state.

Effects of 4-hydroxynonenal on adenylate cyclase and 5′-nucleotidase activities in rat liver plasma membranes

1985 ◽  
Vol 53 ◽  
pp. 209-217 ◽  
Author(s):  
Luciana Paradisi ◽  
Carla Panagini ◽  
Maurizio Parola ◽  
Giuseppina Barrera ◽  
Mario U. Dianzani
Keyword(s):  
Adenylate Cyclase ◽  
Rat Liver ◽  
Plasma Membranes ◽  
Liver Plasma Membranes ◽  
Rat Liver Plasma Membranes

scholarly journals The effect of fluoride on the state of aggregation of adenylate cyclase in rat liver plasma membranes

1980 ◽  
Vol 188 (1) ◽  
pp. 137-140 ◽  
Author(s):  
B R Martin ◽  
J M Stein ◽  
E L Kennedy ◽  
C A Doberska
Keyword(s):  
Adenylate Cyclase ◽  
Rat Liver ◽  
Plasma Membranes ◽  
The State ◽  
Target Size ◽  
Liver Plasma Membranes ◽  
Rat Liver Plasma Membranes

Irradiation inactivation was used to monitor changes in the state of adenylate cyclase in rat liver plasma membranes in the presence of F-.F- caused a decrease in the target size from 328000 to 237000 at 0 degrees C and from 329000 to 219000 at 30 degrees C. Adenylate cyclase was activated by F- at both 0 degrees C and 30 degrees C. The effect of F- was biphasic, activating up to a concentration of 10mM and inhibiting at higher concentrations. If adenylate cyclase weas maximally activated with glucagon and p[NH]ppG ([beta gamma-imido]GTP) all concentrations of F- were inhibitory. The implications of the results with respect to the mechanism of activation of adenylate cyclase are discussed.

Sign in / Sign up

Export Citation Format

Share Document