ABSTRACT
In addition to GPCRs, protein tyrosine kinase-linked receptors such as the epidermal growth factor (EGF), platelet-derived growth factor (PDGF), nerve growth factor (NGF), and tropomyosinrelated kinase (Trk) receptors signal through the PLC/IP
/Ca
pathway by phosphorylation-mediated activation of PLC-
γ
and phosphatidylinositol-3
′
kinase (PI3K) [1]. G-proteins are not linked to this tyrosine kinase signaling pathway (Figure 21.1c).
