Figure 6-2
Phosphorylation
(Illustration of transphosphorylation following receptor clustering – intrinsic kinase activity of hormone (SCF) receptor)
• Advantages of Phosphorylation: rapid, doesn’t require protein synthesis, easily reversed and thus regulated – can easily be returned to unstimulated state which allows a time limit to be set, and allows the signaling pathway to get ready to receive another signal
•First tier of transduction in lymphocytes is accomplished by protein kinases (first, tyrosine kinases, then serine/threonine kinases)
• With antigen receptors these will be Nonreceptor/Receptor associated tyrosine kinases activated following clustering (Src kinases, initiates cascade)
•Some of the kinases will transphosphorylate