Growth Factors and Growth Factor Receptors

Growth factors are proteins secreted by a variety of cells, act through cell surface receptors and can elicit responses in their target cells, leading to cell proliferation and differentiation. Some growth factors are versatile and promote growth in a variety of cells, however others may be specific for a particular cell type. Major families of growth factor receptors are the tyrosine kinases, the small G-protein-coupled receptors (GPCRs), and the serine/threonine kinases.

The figure below shows how cell proliferation is stimulated by growth factors signaling through the lipid signaling pathway. The interaction of a growth factor with its receptor leads to the activation of membrane-associated phospholipase C that hydrolyzes phosphatidylinositol 4,5-diphosphate (PIP2) leading to the formation of diacylglycerol (DAG) and inositol 1,4,5-trisphosphate (IP3). The IP3 causes the release of endogenous Ca2+ that binds to the cytosolic PKC and exposes the phospholipid-binding site. The binding of Ca2+ translocates PKC to the membrane where it interacts with DAG to transform PKC into a fully active enzyme.

Cell proliferation is stimulated by growth factors signaling through the lipid signaling pathway.

Cell proliferation is stimulated by growth factors signaling through the lipid signaling pathway.