Platelet activation by bacterial phospholipase C involves phosphoinositide turnover and phosphorylation of 47,000 dalton but not 20,000 dalton protein

Conference · Thu May 01 00:00:00 EDT 1986 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:5179338

Huzoor-Akbar,; Anwer, K

This study was conducted to examine the role of phosphoinositides (PIns) and phosphorylation of 47,000 dalton (P47) and 20,000 dalton (P20) proteins in platelet activation by bacterial phospholipase C (PLC). PLC induced serotonin secretion (SS) and platelet aggregation (PA) in a concentration dependent manner. PLC (0.02 U/ml) caused phosphorylation of P47 in a time dependent manner (27% at 0.5 min to 378% at 7 min). PLC did not induce more than 15% phosphorylation of P20 by 7 min. Aspirin (500 ..mu..M) blocked phosphorylation of P20 but did not inhibit SS, PA or phosphorylation of P47. PLC (0.04 U/ml) decreased radioactivity (cpm) in /sup 32/P labeled phosphatidylinositol (PI), PI-4,5-bis-PO4 (PIP2) and PI-4-PO4 (PIP) by 20%, 12% and 7.5% respectively at 15 sec. The level of PI but not that of PIP2 returned to base line in 3 min. PIP level increased above control values within one min. PLC increased phosphatidic acid level (75% at 0.5 min. to 1545% at 3 min). In other experiments PLC produced diacylglycerol (DAG) in a time and concentration dependent manner. However, no DAG was detectable in the first 60 sec. These data suggest that: (a) PIns turnover and phosphorylation of P47 but not that of P20 is involved in platelet activation by PLC; and (b) DAG production from outer membrane phospholipids is not a prerequisite for platelet activation by PLC.

• Research Organization: Ohio Univ., Athens
• OSTI ID: 5179338
• Report Number(s): CONF-8606151-
• Journal Information: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Vol. 45:6; Conference: 76. annual meeting of the Federation of American Society for Experimental Biology, Washington, DC, USA, 8 Jun 1986
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
BLOOD PLATELETS
BLOOD COAGULATION
LIPASE
ENZYME ACTIVITY
PROTEINS
PHOSPHORYLATION
CELL MEMBRANES
PHOSPHOLIPIDS
PHOSPHORUS 32
TRACER TECHNIQUES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY FLUIDS
CARBOXYLESTERASES
CELL CONSTITUENTS
CHEMICAL REACTIONS
DAYS LIVING RADIOISOTOPES
ENZYMES
ESTERASES
ESTERS
HYDROLASES
ISOTOPE APPLICATIONS
ISOTOPES
LIGHT NUCLEI
LIPIDS
MATERIALS
MEMBRANES
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
PHOSPHORUS ISOTOPES
RADIOISOTOPES
550201* - Biochemistry- Tracer Techniques