Epidermal growth factor and platelet-derived growth factor promote translocation of phospholipase C-gamma from cytosol to membrane.
Treatment of HER 14 cells with epidermal growth factor (EGF) or platelet-derived growth factor (PDGF) induced a translocation of phospholipase C-gamma (PLC-gamma) from cytosol to membrane. In such growth factor-treated cells, cytosolic PLC-gamma was found to contain more phosphotyrosine than membrane-associated enzyme. Because these growth factors have been shown to promote both the physical association of PLC-gamma with their receptors and the subsequent phosphorylation of the enzyme directly by the membrane-bound receptor tyrosine kinases, the membrane association of PLC-gamma may simply be due to the formation of transient enzyme (receptor)-substrate (PLC-gamma) complexes. If this is the case, membrane-associated PLC-gamma would be expected to be released from membrane after undergoing tyrosine phosphorylation. However, tyrosine phosphorylation of membrane-associated PLC-gamma by the EGF receptor in vitro did not result in the release of PLC-gamma from membrane. Thus, the association of PLC-gamma with membrane would appear to involve more than enzyme-substrate complex.
Kim
U H
UH
Laboratory of Biochemistry, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892.
Kim
H S
HS
Rhee
S G
SG
D000818:Animals; D001692:Biological Transport / Q000502:physiology; D002462:Cell Membrane / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D004815:Epidermal Growth Factor / Q000502:physiology*; D066246:ErbB Receptors / Q000378:metabolism; D006801:Humans; D010766:Phosphorylation; D010982:Platelet-Derived Growth Factor / Q000502:physiology*; D011233:Precipitin Tests; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000378:metabolism; D017479:Receptors, Platelet-Derived Growth Factor; D010738:Type C Phospholipases / Q000378:metabolism*
D010982:Platelet-Derived Growth Factor; D011956:Receptors, Cell Surface; D004815:Epidermal Growth Factor; D066246:ErbB Receptors; D011505:Protein-Tyrosine Kinases; D017479:Receptors, Platelet-Derived Growth Factor; D010738:Type C Phospholipases