Binding of SH2 domains of phospholipase C gamma 1, GAP, and Src to activated growth factor receptors

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作者：

D Anderson，C Koch，L Grey，C Ellis，M Moran，T Pawson

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摘要：

Phospholipase C$_\gamma$1 (PLC$_\gamma$1) and p21$^{ras}$ guanosine triphosphatase (GTPase) activating protein (GAP) bind to and are phosphorylated by activated growth factor receptors. Both PLC$_\gamma$1 and GAP contain two adjacent copies of the noncatalytic Src homology 2 (SH2) domain. The SH2 domains of PLC$_\gamma$1 synthesized individually in bacteria formed high affinity complexes with the epidermal growth factor (EGF)- or platelet derived growth factor (PDGF)-receptors in cell lysates, and bound synergistically to activated receptors when expressed together as one bacterial protein. In vitro complex formation was dependent on prior growth factor stimulation and was competed by intracellular PLC$_\gamma$1. Similar results were obtained for binding of GAP SH2 domains to the PDGF-receptor. The isolated SH2 domains of other signaling proteins, such as p60$^{src}$ and Crk, also bound activated PDGF-receptors in vitro. SH2 domains, therefore, provide a common mechanism by which enzymatically diverse regulatory proteins can physically associate with the same activated receptors and thereby couple growth factor stimulation to intracellular signal transduction pathways.

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关键词：

GTPase-Activating Proteins Proteins Receptor, Epidermal Growth Factor Receptors, Platelet-Derived Growth Factor Receptors, Cell Surface Sequence Homology, Nucleic Acid Phosphorylation Genes, src Type C Phospholipases