CELL201 Lecture Notes - Lecture 11: Protein Kinase, Dissociation Constant, Agonist

• School: University of Alberta
• Department: Cell Biology
• Course: CELL201
• Professor: Paul Lapointe

Document Summary

Reduce density of receptors on their surface vis receptor- mediated endocytosis. Desensitisation (lower affinity for ligand and prevent downstream intracellular events)- phosphorylation. Categories of receptors: g proteins, receptor-linked kinases. Protein kinase associated receptors: receptors and kinases, ligand binding stimulates kinase activities, signalling of these receptor protein kinases is transmitted through a phosphorylation cascade. Growth factors binds to protein kinase associated receptors. Receptors form dimers upon ligand binding and phosphorylate each other (autophosphorylation) Non receptor tyrosine kinase- receptor and protein kinase are separate proteins, jak binds to receptor and is activates upon ligand binding. Tyrosine kinase- src, regulated in two phosphorylation sites. Phosphorylated tyrosine residues can be recognised by sh2 domains. Proteins containing sh2 are recruited to proteins containing phosphorylated tyrosine residues: activation of receptor tyrosine kinases (rtk) leads to the activation of ras to raf kinase to map kinase. Ras is important for regulating cell growth, it is a small monomeric g-protein. Requires gef- (sos) to acquire a gtp molecule.