Specific receptor for inositol-1,4,5-trisphosphate in permeabilized rabbit neutrophils

Journal Article · Wed Mar 05 04:00:00 EST 1986 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:6802081

Bradford, P G; Spat, A; Rubin, R P

Neutrophil chemotaxis and degranulation are resultant, in part, from the mobilization of intracellular calcium by inositol-1,4,5-trisphosphate ((1,4,5)IP/sub 3/), one of the products of chemoattractant-stimulated phospholipase C activity. High specific activity (ca. 40 Ci/mmol) (/sup 32/P)(1,4,5)IP/sub 3/ was prepared from (..gamma..-/sup 32/P)ATP-labeled human erythrocyte ghosts and was used in binding assays with saponin-permeabilized rabbit peritoneal neutrophils. At 4/sup 0/C and in the presence of inhibitors of the IP/sub 3/ 5-phosphomonoesterase, (/sup 32/P)(1,4,5)IP/sub 3/ rapidly associated with a specific binding component which saturated within 60s. Nonspecific binding, taken as the residual binding in the presence of 10 ..mu..M (1,4,5)IP/sub 3/, was 15% of the total. No specific binding was detected using intact cells. The specific binding to permeable cells was reversible (t/sup 1/2/ approx. 60s) and could be inhibited in a dose-dependent manner by (1,4,5)IP/sub 3/ (EC/sub 50/ = 30 nM) and by other calcium mobilizing inositol phosphates ((2,4,5)IP/sub 3/) but not by inactive analogs ((1,4)IP/sub 2/, (4,5)IP/sub 2/, (1)IP). The dose-responses of (1,4,5)IP/sub 3/ and (2,4,5)IP/sub 3/ in inhibiting (/sup 32/P)(1,4,5)IP/sub 3/ specific binding correlated well with their abilities to release Ca/sup 2 +/ from nonmitochondrial vesicular stores in the same preparation of cells, suggesting that the authors have identified the physiological receptor for (1,4,5)IP/sub 3/.

• Research Organization: Virginia Commonwealth Univ., Richmond
• OSTI ID: 6802081
• Report Number(s): CONF-8604222-
• Journal Information: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States) Vol. 45:4; ISSN FEPRA
• Country of Publication: United States
• Language: English

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550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALKALINE EARTH METAL COMPOUNDS
ANIMALS
ATP
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY FLUIDS
CALCIUM COMPOUNDS
CARBOHYDRATES
CARBOXYLESTERASES
DAYS LIVING RADIOISOTOPES
DOSE-RESPONSE RELATIONSHIPS
ENZYME ACTIVITY
ENZYMES
ESTERASES
ESTERS
HYDROLASES
INOSITOL
INOSITOLS
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
LEUKOCYTES
LIGHT NUCLEI
LIPASE
MAMMALS
MATERIALS
MEMBRANE PROTEINS
MONOSACCHARIDES
NEUTROPHILS
NUCLEI
NUCLEOTIDES
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
PHOSPHORIC ACID ESTERS
PHOSPHORUS 32
PHOSPHORUS ISOTOPES
PROTEINS
RABBITS
RADIOISOTOPES
REACTION KINETICS
RECEPTORS
SACCHARIDES
TRACER TECHNIQUES
VERTEBRATES