G-protein linked receptors activate the G proteins by decreasing the strength of GDP binding. This outcomes in rapid dissociation of bound GDP, which is then replaced by the GTP, which is present in the cytosol in much higher concentrations than GDP. What effects would outcome from a mutation in the alpha subunit of the G protein which caused its affinity for GDP to be decreased without significantly changing its affinity for GTP? Compare the consequences of this mutation with the effects of cholera toxin.