Guanine Nucleotide Regulatory Proteins, Gq and Gi1/2, Mediate Platelet-Activating Factor-Stimulated Phosphoinositide Metabolism in Immortalized Hippocampal Cells

2002 ◽  
Vol 67 (4) ◽  
pp. 1478-1484 ◽  
Author(s):  
Leng-Chu Shi ◽  
Hoau-Yan Wang ◽  
Joel Horwitz ◽  
Eitan Friedman
Keyword(s):  
Platelet Activating Factor ◽  
Regulatory Proteins ◽  
Phosphoinositide Metabolism ◽  
Guanine Nucleotide ◽  
Guanine Nucleotide Regulatory Proteins

scholarly journals Platelet activating factor and U44069 stimulate a GTPase activity in human platelets which is distinct from the guanine nucleotide regulatory proteins, Ns and Ni

1986 ◽  
Vol 234 (3) ◽  
pp. 737-740 ◽  
Author(s):  
M D Houslay ◽  
D Bojanic ◽  
A Wilson
Keyword(s):  
Regulatory Protein ◽  
Platelet Activating Factor ◽  
Phospholipid Metabolism ◽  
Human Platelets ◽  
Regulatory Proteins ◽  
Guanine Nucleotide ◽  
Gtpase Activity ◽  
Guanine Nucleotide Regulatory Proteins ◽  
Gtpase Activation ◽  
Guanine Nucleotide Regulatory Protein

Platelet-activating factor (PAF, 2-acetyl-1-alkyl-sn-glycero-3-phosphocholine) and the stable thromboxane-receptor agonist U44069 (9 alpha, 11 beta-epoxymethanoprostaglandin H2) stimulated GTPase activity in platelet membranes in a dose-dependent fashion, yielding Ka values of 12 nM and 27 nM respectively. The degree of GTPase activation elicited by these agents was found to be additive with the GTPase activation due to either the stimulatory (Ns) or inhibitory (Ni) guanine nucleotide regulatory proteins when activated by prostaglandin E1 and adrenaline (+propranolol) respectively. Treatment of membranes with either cholera or pertussis toxins, which inhibited markedly the receptor-mediated stimulation of the GTPase activities of Ns and Ni respectively, had no or only a small effect, respectively, on the GTPase activity stimulated by PAF and U44069. It is suggested that PAF and U44069, which stimulate inositol phospholipid metabolism in platelets, exert actions through a guanine nucleotide regulatory protein which is distinct from Ns and Ni.

Thrombin-induced prostacyclin biosynthesis in human endothelium: Role of guanine nucleotide regulatory proteins in stimulus/coupling responses

1990 ◽  
Vol 142 (1) ◽  
pp. 186-193 ◽  
Author(s):  
Joe G. N. Garcia ◽  
Richard G. Painter ◽  
John W. Fenton ◽  
Denis English ◽  
Karleen S. Callahan
Keyword(s):  
Regulatory Proteins ◽  
Guanine Nucleotide ◽  
Guanine Nucleotide Regulatory Proteins ◽  
Human Endothelium

An intronless gene encoding a potential member of the family of receptors coupled to guanine nucleotide regulatory proteins

Nature ◽  
1987 ◽  
Vol 329 (6134) ◽  
pp. 75-79 ◽  
Author(s):  
Brian K. Kobilka ◽  
Thomas Frielle ◽  
Sheila Collins ◽  
Theresa Yang-Feng ◽  
Tong Sun Kobilka ◽  
...  
Keyword(s):  
Regulatory Proteins ◽  
Guanine Nucleotide ◽  
Gene Encoding ◽  
Intronless Gene ◽  
The Family ◽  
Guanine Nucleotide Regulatory Proteins ◽  
Potential Member

scholarly journals Thrombin, unlike vasopressin, appears to stimulate two distinct guanine nucleotide regulatory proteins in human platelets

1986 ◽  
Vol 238 (1) ◽  
pp. 109-113 ◽  
Author(s):  
M D Houslay ◽  
D Bojanic ◽  
D Gawler ◽  
S O'Hagan ◽  
A Wilson
Keyword(s):  
Pertussis Toxin ◽  
Plasma Membranes ◽  
Regulatory Protein ◽  
Platelet Activating Factor ◽  
Phospholipid Metabolism ◽  
Human Platelets ◽  
Regulatory Proteins ◽  
Guanine Nucleotide ◽  
Gtpase Activity ◽  
Guanine Nucleotide Regulatory Protein

The thrombin-stimulated GTPase activity of human platelets was additive with respect to the GTPase stimulation effected by prostaglandin E1, but not with that stimulated by adrenaline, vasopressin and platelet-activating factor (PAF). Treatment of platelet membranes with pertussis toxin partially inhibited the thrombin-stimulated GTPase, but had no effect on the vasopressin-stimulated GTPase activity, whereas cholera toxin treatment had no effect on either of these stimulated GTPase activities. Thrombin, adrenaline and PAF, but not vasopressin, inhibited the adenylate cyclase activity of isolated plasma membranes through the action of Ni only, this being inhibited by pertussis toxin. It is suggested that thrombin exerts effects through both the inhibitory guanine nucleotide regulatory protein Ni and through the putative guanine nucleotide regulatory protein, Np, involved in regulating receptor-stimulated inositol phospholipid metabolism. However, vasopressin appears to exert its effects solely through the putative Np.

scholarly journals Evidence that adhesion of electrically permeabilized platelets to collagen is mediated by guanine nucleotide regulatory proteins

1992 ◽  
Vol 286 (3) ◽  
pp. 701-705 ◽  
Author(s):  
J L Daniel ◽  
C Dangelmaier ◽  
J B Smith
Keyword(s):  
Monoclonal Antibodies ◽  
Cytochalasin D ◽  
Regulatory Proteins ◽  
Guanine Nucleotide ◽  
Permeabilized Cells ◽  
Collagen Receptors ◽  
Kinase C ◽  
Protein Kinase C Inhibitor ◽  
Guanine Nucleotide Regulatory Proteins ◽  
Collagen Receptor

Adhesion of electrically permeabilized platelets to collagen was found to be essentially independent of free Ca2+ concentration in the medium. Addition of stable GTP analogues increased the proportion of adhering cells about 5-fold. This effect was inhibited by guanosine 5′-[beta-thio]diphosphate, cytochalasin D or monoclonal antibodies to glycoprotein Ia. In contrast, the protein kinase C inhibitor staurosporine had only a small effect on the GTP-analogue-enhanced adhesion of the permeabilized cells to collagen. These results suggest that a guanine nucleotide regulatory (G)-protein is directly linked to the collagen receptor and is involved in the actin-dependent recruitment of additional collagen receptors.

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