Now, what exactly is the function of CA and P? Well, camp can go on and basically stimulate many affector molecules and effectors can be enzymes or proteins or transcription factors. But inside our body, the most important job of CA and P, in this particular case in the epinephrine signal and transduction pathway is the fact that the cyclic Amp goes on and stimulates it activates protein kinase A molecules. Now, recall from our previous discussion on protein kinase A, or simply PKA. The structure of protein kinase A consists of two types of domains. So we have two regulatory domains and we have two catalytic domains.