NEU 301 Lecture Notes - Lecture 29: Adenylyl Cyclase, Pertussis, Membrane Protein
Document Summary
A single polypeptide chain that snakes back and forth through the pm 7 times. Signal binds to gpcr, which changes shape, decreasing alpha subunit"s affinity for gdp. It is exchanged for gtp causing activation and separation from activated by subunit. These interact with target proteins in the pm that relay the signal to other places. G-protein structure alpha, beta, and gamma subunits, 2 tethered to the protein membrane. The longer it is bound to the target protein, the longer the signal is relayed. The alpha subunit hydrolyzes gtp to gdp, causing all subunits to unbind from their target proteins and form one inactive g-protein unit. It produces a protein that modifies the alpha subunit of a g-protein in the intestine, inhibiting it from hydrolyzing gtp to gdp. It is thus locked in the active state, continually stimulating adenylyl cyclase, inc. camp, activating. Pk, opening chloride channels, causing sodium to leave. Thus water leaves the gut, causing diarrhea and dehydration.
