BIO270H1 Lecture Notes - Lecture 5: Phosphatidylinositol, Cgmp-Dependent Protein Kinase, Adenylyl Cyclase
Document Summary
Signal transduction pathways: convert the change in receptor shape to an intracellular response, 4 components. Conformation change of the receptor which activates. Molecular functions that change in response to signal. Transduction pathway: ligand binds to receptor and continues to activate, amplification of molecules. Most for genomic effects: ligand-gated ion channels. Ligand gated ion channels: ligand binds to transmembrane receptors, receptors open, travels down the electrochemical gradient, direct and rapid. Receptor enzymes: ligand binds to transmembrane receptors, receptors dimerize and autophosphorylate, protein kinases signals to ras protein, ras switches between active and inactive forms. Second mesengers: a short lived intracellular messenger that acts as an intermediate in signal transduction pathway, ca2+, cgmp, camp and phosphatidyl inositol. Guanylate cyclate activates protein kinases (usually protein kinase g) Interaction among transduction pathways: cells have receptor for different ligands, response of the cell depends on complex interactions, ex. Ca2+-cam interacts with adenylate cyclase and camp pde: pka can phosphorylate ca2+-channels.
