Constitutive activation of the m5 muscarinic receptor by as series of mutations at the extracellular end of transmembrane 6

The m5 muscarinic receptor constitutive activation was investigated to determine the structural implications and mechanisms involved in the phenomenon. The study utilized a series of mutations at the extracellular end of transmembrane 6. Results of the research showed that the primary effect of substitution favors the formation of the active state without the need for agonists. The results also prove the significant role of a two-state model of receptor function in the activation of muscarinic receptors.