LIFE 210 Lecture Notes - Adenylyl Cyclase, Inositol, Transmembrane Protein
Document Summary
A g-protein coupled receptor (gpcr) is a 7 pass transmembrane protein. They use g proteins to relay signals into the cell interior. Gpcr pathways are targets of half of all known drugs. Inactive when the subunit has gdp bound. Gpcr activation induces the subunit to release gdp to bind gtp. An active gpcr catalyzes the activation of many molecules of g protein. Active g protein regulates enzymes or ion channels in the plasma membrane (conformational change) Synthesized by adenylyl cyclase and degraded by a phosphodiesterase. Extracellular signals can increase camp 20x in a few seconds. Different cell types respond differently to increases in camp. One cell type often responds in the same way, regardless of the extracellular signal that causes it. This is because the receptors are different; they bind the same signal, but relay the message differently. Cyclic amp-dependent protein kinase (pka) mediates most of the effects of cyclic amp.
