This receptor is directly associated with one of its ultimate effectors, the class C L-type calcium channel CaV1.2. This receptor-channel complex is coupled to the Gs G protein, which activates adenylyl cyclase, catalysing the formation of cyclic adenosine monophosphate (cAMP) which then activates protein kinase A, and the counterbalancing phosphatase PP2A. The assembly of the signaling complex provides a mechanism that ensures specific and rapid signaling. A two-state biophysical and molecular model has been proposed to account for the pH and REDOX sensitivity of this and other GPCRs.[6]