Regulation of G protein function: Implications for heart disease

1996 ◽  
pp. 31-38
Author(s):  
Johanna T. A. Meij
Keyword(s):  
Heart Disease ◽  
G Protein ◽  
Protein Function

Disturbing Gtp-Binding Protein Function Through Microinjection Into The Visual Cell Of Limulus

1992 ◽  
Vol 47 (11-12) ◽  
pp. 915-921 ◽  
Author(s):  
Henmg Stieve ◽  
Barbara Niemeyer ◽  
Klaus Aktories ◽  
Heidi E. Hamm
Keyword(s):  
Monoclonal Antibody ◽  
G Protein ◽  
Protein Function ◽  
Clostridium Botulinum ◽  
Functional Role ◽  
Electrical Response ◽  
Visual Cell ◽  
Gtp Binding ◽  
Dim Light ◽  
Ventral Nerve Photoreceptor

We have tested the action of three agents microinjected into the ventral nerve photoreceptor of Limulus on the electrical response to dim light. 1. A monoclonal antibody (mAb 4 A) against the Gɑ subunit of frog transducin reduces the size of the receptor current to 60%, suggesting an interaction with Gɑ in the Limulus photoreceptor. 2. Injection of Clostridium botulinum ADPribosyltransferase C 3 reduces the size to 46%; latency is not affected. The results imply that small GTP-binding proteins play a functional role in photoreception of invertebrates. 3. Injection of GD P-β-S reduces dose-dependently the size of the receptor current to 15% and prolongs the latency to 200%, presumably by reducing number and rate of G-protein activations

β-Adrenoceptor control of G protein function in the neonate: determinant of desensitization or sensitization

2002 ◽  
Vol 283 (5) ◽  
pp. R1236-R1244 ◽  
Author(s):  
J. T. Auman ◽  
F. J. Seidler ◽  
T. A. Slotkin
Keyword(s):  
G Protein ◽  
Strong Evidence ◽  
Protein Function ◽  
Membrane Fraction ◽  
Repeated Administration ◽  
Receptor Function ◽  
Newborn Rats ◽  
Selective Agonist ◽  
The Face ◽  
Tissue Selectivity

Neonatal β-adrenoceptors (β-ARs) are resistant to agonist-induced desensitization. We examined the functioning of Gi and Gs after repeated administration of β-AR agonists to newborn rats. Isoproterenol (β1/β2 agonist) obtunded Gi function in the heart but not the liver; in contrast, terbutaline, a β2-selective agonist, enhanced Gi function. Isoproterenol, but not terbutaline, increased membrane-associated Gsα, which would enhance receptor function. In addition, isoproterenol increased and terbutaline maintained the proportion of the short-splice (S) variant of Gsα in the membrane fraction; GsαS is functionally more active than the long-splice variant. Either isoproterenol or terbutaline treatment increased Gsα in the cytosolic fraction, a characteristic usually associated with desensitization in the adult. Decreased Gi activity, coupled with increased membrane-associated Gsαconcentrations and maintenance or increases in membrane GsαS, provide strong evidence that unique effects on G protein function underlie the ability of the immature organism to sustain β-AR cell signaling in the face of excessive or prolonged stimulation; these mechanisms also contribute to tissue selectivity of the effects of β-agonists with divergent potencies toward different β-AR subtypes.

scholarly journals Pertussis toxin treatment of whole blood. A novel approach to assess G protein function in congestive heart failure.

Circulation ◽  
1990 ◽  
Vol 81 (4) ◽  
pp. 1198-1204 ◽  
Author(s):  
A S Maisel ◽  
M C Michel ◽  
P A Insel ◽  
C Ennis ◽  
M G Ziegler ◽  
...  
Keyword(s):  
Heart Failure ◽  
Congestive Heart Failure ◽  
G Protein ◽  
Pertussis Toxin ◽  
Whole Blood ◽  
Protein Function ◽  
Novel Approach

Yeast Small G-Protein Function

2010 ◽  
pp. 1813-1817
Author(s):  
Keith G. Kozminski ◽  
Hay-Oak Park
Keyword(s):  
G Protein ◽  
Protein Function ◽  
Small G Protein
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