BIOL201 Lecture Notes - Lecture 15: Myosin Light-Chain Kinase, Arteriole, Tyrosine Kinase
Document Summary
Alpha adrenergic receptor signaling: epinephrine binds to receptor on smooth muscle cells in intestinal arterioles. Figure 14-10: gdp goes away and gtp binds to alpha subunit: activates it. Now the alpha subunit can bind to phospholipase c activating it and causing cleavage of pip2 into ip3 and dag. Alpha subunit: is dissociated from beta and gamma, there"s also a conformational change. Pip2 and its cleavage products: ip3 and dag. Hydroxyl is attached to phosphate group with a sugar. Bottom: cleaving: two fatty acid chains bound to glycerol (dag) plus ip3: has. 3 phosphate groups now because one phosphate was taken from up. This is very polar, so it can diffuse away from the membrane. Ip3 diffuses away from the membrane: goes to membrane of er where there is an ip3 receptor channel (ligand gated channel). Channel opens (this channel is specific for allowing the passing of ca2+ through the membrane.