Physiology 3140A Lecture Notes - Lecture 16: Platelet-Derived Growth Factor, Ephrin, Grb2

• School: Western University
• Department: Physiology
• Course: Physiology 3140A
• Professor: John Di Guglielmo

Document Summary

Their c-terminal either have intrinsic enzymatic activity or are directly associated with cytosolic enzymes. Each subunit of an enzyme-linked receptor has one transmembrane spanning domain. Only insulin receptor family receptors are dimers (inactive) Ligand binding causes a conformational change, bringing two internal kinase domains together. Rtk ligands: cell surface bound growth factors: ephrin, secreted growth factors: e. g. vegef, cell surface bound ligands: Regulate: angiogenesis, axon guidance, synaptic plasticity: secreted growth factors. Egf, pdgf, fgf, hgf, ifg-1, vegf, m-csf, ngf can be dimers or monomers, pdgf is covalently linked as a dimer: dimeric ligand: Pdgf is covalently linked dimer with two distinct receptor binding domains. Pdgf can crosslink and dimerize two adjacent pdgf receptors to initiate intracellular signalling. Dimerization orients the kinase domains: phosphorylation of thyr residues in c- tail of both receptors. Kinases phosphorylate the adjacent tail on several tyrosines: transactivation -> receptor autophosphorylation. Receptor acts a molecular scaffold (like betaarrestin can).