BIO 360 Chapter Notes - Chapter 12: Insulin Receptor, Irs1, Peptide Hormone
Document Summary
* most common catalytic domains have tyrosine kinase activity. Adds a phosphate group to itself (autophosphorylation " conformational change allowing binding + catalytic phosphorylation of specific target proteins. Adds a phosphate group to a tyrosine in specific target proteins. * some catalytic domains have guanylyl cyclase activity convert gtp to cgmp , a secondary messenger. Insulin interacts with cell via receptor tyrosine kinase. Peptide hormone that is produced by 13 cells of islets of langerhans in pancreas. Reaches target cells ( liver , muscle, or fat cells ) v1 a bloodstream. Binding to receptor initiates a cascade of events ( leads to increased glucose uptake and metabolism. Inability to make / sense insulin = diabetes. Insulin binds to extracellular domains of receptor activates catalytic domain inside cell catalytic domain in one receptor phosphorylates tyr residues in another receptor. Receptor autophosphorylation allows binding and phosphorylation of protein irs -1.