Regulation of Phosphoinositide-Specific Phospholipase C Activity in Human Platelets

1993 ◽  
pp. 37-47 ◽  
Author(s):  
Yoshinori Nozawa ◽  
Yoshiko Banno ◽  
Koh-ichi Nagata
Keyword(s):  
Phospholipase C ◽  
Human Platelets

Possible regulation of phospholipase C activity in human platelets by phosphatidylinositol 4′,5′-bisphosphate

1984 ◽  
Vol 228 (1) ◽  
pp. 299-308 ◽  
Author(s):  
Gustav Graff ◽  
Nabeel Nahas ◽  
Maria Nikolopoulou ◽  
Viswanathan Natarajan ◽  
Harald H.O. Schmid
Keyword(s):  
Phospholipase C ◽  
Human Platelets ◽  
Phosphatidylinositol 4

Stimulation by G Protein βγ Subunits of Phospholipase C β Isoforms in Human Platelets

1998 ◽  
Vol 79 (05) ◽  
pp. 1008-1013 ◽  
Author(s):  
Yoshiko Banno ◽  
Tomiko Asano ◽  
Yoshinori Nozawa
Keyword(s):  
Phospholipase C ◽  
G Protein ◽  
G Proteins ◽  
Human Platelet ◽  
Minor Component ◽  
Similar Efficacy ◽  
Human Platelets ◽  
Bovine Brain ◽  
Γ Subunit ◽  
A Minor

SummaryDifferent phospholipase C (PLC) isoforms were located in human platelet cytosol and membranes. PLCγ2 and PLCβ3b were mainly located in the cytosol and PLCβ2 and PLCβ3a were in both cytosol and membranes by using specific antibodies against PLC isozymes (Banno Y, Nakashima S, Ohzawa M, Nozawa Y. J Biol Chem 1996; 271: 14989-94). Three PLC fractions activated by G protein βγ subunits were purified from human platelet cytosol and membrane fractions. Two PLC fractions from membranes were identified as PLCβ2 and PLCβ3a, and one from cytosol was PLCβ3b. These PLCβ isoforms were activated by the purified βγ subunits of brain G proteins in the order PLCβ3b > PLCβ3a > PLCβ2. Western blot analysis of γ subunits of the purified platelet G proteins with antibodies against various standard γ subunits revealed that the major component of the γ subunit of Gi2 and Gq was γ5, and that γ7 was a minor component. Studies using various subtypes of βγ subunits, βγ2, βγ3, and βγ7 purified from bovine brain, βγ5 from bovine lung, or βγ12 from bovine spleen, failed to show differences in their ability to stimulate the isolated platelet PLCβ isoforms. These results suggest that the βγ subunits of Gi2 and Gq have similar efficacy in regulation of effectors in human platelets.

Effect of Phospholipase C on Human Platelets

1975 ◽  
Author(s):  
A.-B. Otnœss
Keyword(s):  
Bacillus Cereus ◽  
Phospholipase C ◽  
Electron Micrographs ◽  
Gel Filtration ◽  
Outer Part ◽  
Human Platelets ◽  
Scanning Electron Micrographs ◽  
Platelet Factor ◽  
Asymmetrical Distribution ◽  
Scanning Electron

The effect on human platelets of phospholipase C (Bacillus cereus) has been studied. Platelets prepared by gel filtration lost 20-30% of their phospholipids when incubated with phospholipase C for 20 min. Phosphatidylethanolamine (PE) was reduced by about 50%, whereas phosphatidylcholine and phosphatidylserine were reduced each by about 20%. Sphingomyelin was not reduced.These data suggest an asymmetrical distribution of phospholipids in the platelet membrane, PE being more accessible and therefore probably mainly located in the outer part of the membrane.The loss of phospholipids was not accompanied by aggregation, nor did the platelets lose their ability to aggregate with thrombin or ADP. Data on release of serotonin, platelet factor 3 and 4 and scanning electron micrographs of treated platelets will be given.

Ionophore A23187 stimulates phosphorylation of the 40, 000dalton protein in human platelets without phospholipase C activation

Life Sciences ◽  
1986 ◽  
Vol 39 (8) ◽  
pp. 751-759 ◽  
Author(s):  
Eduardo G. Lapetina ◽  
Bryan Reep ◽  
Stephen P. Watson
Keyword(s):  
Phospholipase C ◽  
Human Platelets ◽  
Ionophore A23187

Pertussis toxin sensitive G-protein coupling of HDL receptor to phospholipase C in human platelets

1992 ◽  
Vol 67 (5) ◽  
pp. 559-567 ◽  
Author(s):  
H. Nazih ◽  
D. Devred ◽  
F. Martin-Nizard ◽  
V. Clavey ◽  
J.C. Fruchart ◽  
...  
Keyword(s):  
Phospholipase C ◽  
G Protein ◽  
Pertussis Toxin ◽  
Human Platelets ◽  
G Protein Coupling ◽  
Protein Coupling

Evidence for separate effects of U73122 on phospholipase C and calcium channels in human platelets

1998 ◽  
Vol 56 (11) ◽  
pp. 1481-1484 ◽  
Author(s):  
Fabio M. Pulcinelli ◽  
Paolo Gresele ◽  
Margherita Bonuglia ◽  
Pier Paolo Gazzaniga
Keyword(s):  
Calcium Channels ◽  
Phospholipase C ◽  
Human Platelets
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