Phosphorylation of erythrocyte membrane liberates calcium
Phosphorylation of permeabilized erythrocyte ghost membranes with ATP results in an increase free calcium level as measured with the help of Ca/sup 2 +/ electrode and /sup 45/Ca. This effect could not be observed in the presence of p/sup -/ chloromercuric benzoate, an inhibitor of kinases. The rise in the free calcium due to phosphorylation of the membrane was accompanied by a decrease in the level of phosphatidylinositol (PI) and an increase in phosphatidylinositolmonophosphate (PIP) and phosphatidylinositolbisphosphate (PIP/sub 2/). These results support the proposal that an inositol shuttle, PI in equilibrium PIP in equilibrium PIP/sub 2/, operates to maintain the intracellular calcium concentration. The cation is believed to be sequestered in a cage formed by the head groups of two acidic phospholipid molecules, e.g., phosphatidylserine and phosphatidylinositol, with the participation of both PO and fatty acid ester CO groups. When the inositol group of such a cage is phosphorylated, inter-headgroup hydrogen bonding between the lipids is broken. As a result the cage opens and calcium is released.
- Research Organization:
- Institute for Basic Research in Developmental Disabilities, Staten Island, NY
- OSTI ID:
- 5096448
- 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
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Related Subjects
CALCIUM COMPOUNDS
SECRETION
CELL MEMBRANES
PHOSPHORYLATION
PHOSPHOLIPIDS
ATP
CALCIUM 45
CATIONS
ERYTHROCYTES
INOSITOL
ALKALINE EARTH ISOTOPES
ALKALINE EARTH METAL COMPOUNDS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY FLUIDS
CALCIUM ISOTOPES
CARBOHYDRATES
CELL CONSTITUENTS
CHARGED PARTICLES
CHEMICAL REACTIONS
DAYS LIVING RADIOISOTOPES
ESTERS
EVEN-ODD NUCLEI
INOSITOLS
INTERMEDIATE MASS NUCLEI
IONS
ISOTOPES
LIPIDS
MATERIALS
MEMBRANES
MONOSACCHARIDES
NUCLEI
NUCLEOTIDES
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
RADIOISOTOPES
SACCHARIDES
550201* - Biochemistry- Tracer Techniques