Selectivity of phospholipase C isozymes in growth factor signaling.
Xenopus laevis oocytes were injected with mRNA extracted from growth factor-responsive CCL39, Chinese hamster lung fibroblasts. The expression of functional growth factor receptors on the oocytes was demonstrated by growth factor-induced 45Ca2+ efflux. To determine the isozyme(s) of phospholipase C (PLC) coupled to growth factor receptors, growth factor-induced 45Ca2+ efflux were measured following coinjection of mRNA from CCL39 cells with PLC antibodies. PLC-gamma 1 antibody did not lead to loss of 45Ca2+ efflux induced by thrombin but resulted in loss of that induced by platelet-derived growth factor (PDGF). In contrast, PLC-delta 1 antibody did not block PDGF-induced 45Ca2+ efflux but led to inhibition of thrombin-induced 45Ca2+ efflux. PLC-beta 1 antibody did not affect Ca2+ efflux by the treatment of either thrombin or PDGF. These results suggest that these growth factor receptors are coupled to specific effectors, i.e. thrombin receptor to PLC-delta 1 and PDGF receptor to PLC-gamma 1.
Cho
Y S
YS
Department of Biochemistry, Chonbuk National University Medical School, Korea.
Han
M K
MK
Chae
S W
SW
Park
C U
CU
Kim
U H
UH
D000818:Animals; D002118:Calcium / Q000378:metabolism; D002460:Cell Line; D006224:Cricetinae; D015151:Immunoblotting; D007527:Isoenzymes / Q000378:metabolism*; D010982:Platelet-Derived Growth Factor / Q000378:metabolism; D017479:Receptors, Platelet-Derived Growth Factor / Q000378:metabolism*; D018179:Receptors, Thrombin / Q000378:metabolism*; D015398:Signal Transduction; D013917:Thrombin / Q000378:metabolism; D010738:Type C Phospholipases / Q000378:metabolism*; D014982:Xenopus laevis
D007527:Isoenzymes; D010982:Platelet-Derived Growth Factor; D018179:Receptors, Thrombin; D017479:Receptors, Platelet-Derived Growth Factor; D010738:Type C Phospholipases; D013917:Thrombin; D002118:Calcium