scholarly journals Phospholipase C Gamma

2020 ◽  
Author(s):  
Keyword(s):  
Phospholipase C ◽  
Phospholipase C Gamma

scholarly journals Nerve growth factor stimulates phosphorylation of phospholipase C-gamma in PC12 cells

1991 ◽  
Vol 266 (3) ◽  
pp. 1359-1362 ◽  
Author(s):  
U H Kim ◽  
D Fink ◽  
H S Kim ◽  
D J Park ◽  
M L Contreras ◽  
...  
Keyword(s):  
Nerve Growth Factor ◽  
Growth Factor ◽  
Phospholipase C ◽  
Pc12 Cells ◽  
Nerve Growth ◽  
Phospholipase C Gamma

scholarly journals Efficient coupling with phosphatidylinositol 3-kinase, but not phospholipase C gamma or GTPase-activating protein, distinguishes ErbB-3 signaling from that of other ErbB/EGFR family members.

1994 ◽  
Vol 14 (1) ◽  
pp. 492-500 ◽  
Author(s):  
P Fedi ◽  
J H Pierce ◽  
P P di Fiore ◽  
M H Kraus
Keyword(s):  
Growth Factor ◽  
Phospholipase C ◽  
Recombinant Expression ◽  
Chimeric Receptor ◽  
Phosphatidylinositol 3 Kinase ◽  
Gtpase Activating Protein ◽  
Ligand Activation ◽  
Phospholipase C Gamma ◽  
Nih 3T3 ◽  
Phosphatidylinositol 3

Recombinant expression of a chimeric EGFR/ErbB-3 receptor in NIH 3T3 fibroblasts allowed us to investigate cytoplasmic events associated with ErbB-3 signal transduction upon ligand activation. An EGFR/ErbB-3 chimera was expressed on the surface of NIH 3T3 transfectants as two classes of receptors possessing epidermal growth factor (EGF) binding affinities comparable to those of the wild-type EGF receptor (EGFR). EGF induced autophosphorylation in vivo of the chimeric receptor and DNA synthesis of EGFR/ErbB-3 transfectants with a dose response similar to that of EGFR transfectants. However, the ErbB-3 and EGFR cytoplasmic domains exhibited striking differences in their interactions with several known tyrosine kinase substrates. We demonstrated strong association of phosphatidylinositol 3-kinase activity with the chimeric receptor upon ligand activation comparable in efficiency with that of the platelet-derived growth factor receptor, while the EGFR exhibited a 10- to 20-fold-lower efficiency in phosphatidylinositol 3-kinase recruitment. By contrast, both phospholipase C gamma and GTPase-activating protein failed to associate with or be phosphorylated by the ErbB-3 cytoplasmic domain under conditions in which they coupled with the EGFR. In addition, though certain signal transmitters, including Shc and GRB2, were recruited by both kinases, EGFR and ErbB-3 elicited tyrosine phosphorylation of distinct sets of intracellular substrates. Thus, our findings show that ligand activation of the ErbB-3 kinase triggers a cytoplasmic signaling pathway that hitherto is unique within this receptor subfamily.

Structural requirements for enhancement of T-cell responsiveness by the lymphocyte-specific tyrosine protein kinase p56lck

1992 ◽  
Vol 12 (6) ◽  
pp. 2720-2729
Author(s):  
L Caron ◽  
N Abraham ◽  
T Pawson ◽  
A Veillette
Keyword(s):  
T Cell ◽  
Protein Phosphorylation ◽  
Phospholipase C ◽  
Interleukin 2 ◽  
Cell Receptor ◽  
Amino Terminal ◽  
Src Homology ◽  
Phospholipase C Gamma ◽  
Domain 3

To understand the mechanism(s) by which p56lck participates in T-cell receptor (TCR) signalling, we have examined the effects of mutations in known regulatory domains of p56lck on the ability of F505 p56lck to enhance the responsiveness of an antigen-specific murine T-cell hybridoma. A mutation of the amino-terminal site of myristylation (glycine 2), which prevents stable association of p56lck with the plasma membrane, completely abolished the ability of F505 p56lck to enhance TCR-induced tyrosine protein phosphorylation. Alteration of the major site of in vitro autophosphorylation, tyrosine 394, to phenylalanine diminished the enhancement of TCR-induced tyrosine protein phosphorylation by F505 p56lck. Such a finding is consistent with the previous demonstration that this site is required for full activation of p56lck by mutation of tyrosine 505. Strikingly, deletion of the noncatalytic Src homology domain 2, but not of the Src homology domain 3, markedly reduced the improvement of TCR-induced tyrosine protein phosphorylation by F505 Lck. Additional studies revealed that all the mutations tested, including deletion of the Src homology 3 region, abrogated the enhancement of antigen-triggered interleukin-2 production by F505 p56lck, thus implying more stringent requirements for augmentation of antigen responsiveness by F505 Lck. Finally, it was also observed that expression of F505 p56lck greatly increased TCR-induced tyrosine phosphorylation of phospholipase C-gamma 1, raising the possibility that phospholipase C-gamma 1 may be a substrate for p56lck in T lymphocytes. Our results indicate that p56lck regulates T-cell antigen receptor signalling through a complex process requiring multiple distinct structural domains of the protein.

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