PMID- 2136853
OWN - NLM
STAT- MEDLINE
DCOM- 19900221
LR  - 20210210
IS  - 0021-9258 (Print)
IS  - 0021-9258 (Linking)
VI  - 265
IP  - 3
DP  - 1990 Jan 25
TI  - A guanine nucleotide-binding protein participates in IgE receptor-mediated 
      activation of endogenous and reconstituted phospholipase A2 in a permeabilized 
      cell system.
PG  - 1459-64
AB  - Activation of phospholipase A2 (PLA2) by the aggregation of receptors for 
      immunoglobulin E (IgE) can be studied in streptolysin O-permeabilized rat 
      basophilic leukemia cells. Under these conditions, 40 microM guanosine 
      5'-O-(3-thio)triphosphate (GTP gamma S) stimulates PLA2 activity 5-6-fold when 
      free Ca2+ concentrations are buffered at 10(-7)-10(-5) M. Antigen-mediated 
      cross-linking of receptors for IgE synergizes with low concentrations of GTP 
      gamma S (0.1 microM) to cause similar stimulation. When the endogenous PLA2 
      activity is inactivated by chemical modification, we find that exogenously 
      supplied PLA2 from porcine pancreas and Naja naja venom is also activated by the 
      aggregation of cell-surface IgE receptors in these permeabilized cells. As with 
      endogenous PLA2, GTP gamma S synergizes with IgE receptor-aggregation to activate 
      exogenous PLA2 approximately 10-fold at 10(-7)-10(-6) M free Ca2+. These data 
      indicate that receptor-mediated activation of a guanine nucleotide-binding 
      protein can shift the Ca2+ dependence of PLA2 activity resulting in greatly 
      enhanced activity at physiological concentrations of intracellular free Ca2+. The 
      partial reconstitution of various PLA2 forms into such a broken-cell system 
      offers a new approach for studying the mechanisms of G-protein-mediated 
      activation of PLA2.
FAU - Narasimhan, V
AU  - Narasimhan V
AD  - Section of Biochemistry, Molecular and Cell Biology, Cornell University, Ithaca, 
      New York.
FAU - Holowka, D
AU  - Holowka D
FAU - Baird, B
AU  - Baird B
LA  - eng
GR  - AI18306/AI/NIAID NIH HHS/United States
GR  - AI22449/AI/NIAID NIH HHS/United States
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, Non-P.H.S.
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - J Biol Chem
JT  - The Journal of biological chemistry
JID - 2985121R
RN  - 0 (Antigen-Antibody Complex)
RN  - 0 (Antigens, Differentiation, B-Lymphocyte)
RN  - 0 (Receptors, Fc)
RN  - 0 (Receptors, IgE)
RN  - 0 (Thionucleotides)
RN  - 37341-29-0 (Immunoglobulin E)
RN  - 37589-80-3 (Guanosine 5'-O-(3-Thiotriphosphate))
RN  - 86-01-1 (Guanosine Triphosphate)
RN  - EC 3.1.- (Phospholipases)
RN  - EC 3.1.1.32 (Phospholipases A)
RN  - EC 3.1.1.4 (Phospholipases A2)
RN  - EC 3.6.1.- (GTP-Binding Proteins)
RN  - SY7Q814VUP (Calcium)
SB  - IM
MH  - Animals
MH  - Antigen-Antibody Complex/physiology
MH  - Antigens, Differentiation, B-Lymphocyte/*metabolism
MH  - Basophils/*physiology
MH  - Calcium/physiology
MH  - Cell Membrane Permeability
MH  - Enzyme Activation
MH  - GTP-Binding Proteins/*physiology
MH  - Guanosine 5'-O-(3-Thiotriphosphate)
MH  - Guanosine Triphosphate/analogs & derivatives/pharmacology
MH  - Immunoglobulin E/*physiology
MH  - Phospholipases/*metabolism
MH  - Phospholipases A/*metabolism
MH  - Phospholipases A2
MH  - Rats
MH  - Receptors, Fc/*metabolism
MH  - Receptors, IgE
MH  - Thionucleotides/pharmacology
MH  - Tumor Cells, Cultured
EDAT- 1990/01/25 00:00
MHDA- 1990/01/25 00:01
CRDT- 1990/01/25 00:00
PHST- 1990/01/25 00:00 [pubmed]
PHST- 1990/01/25 00:01 [medline]
PHST- 1990/01/25 00:00 [entrez]
AID - S0021-9258(19)40038-0 [pii]
PST - ppublish
SO  - J Biol Chem. 1990 Jan 25;265(3):1459-64.