In a signal transduction cascade using G-proteins and cAMP, which of the following is not a signal amplification step?

In a signal transduction cascade using G-proteins and cAMP, which of the following is not a signal amplification step?

In a signal transduction cascade using G-proteins and cAMP, which of the following is not a signal amplification step?





  1. Activation of G-proteins by an activated receptor
  2. Activation of adenylyl cyclase molecules by G-proteins
  3. Creation of cAMP molecules by adenylyl cyclase
  4. Phosphorylation of target proteins by protein kinase A
  5. All of the above are steps in which amplification occurs.

Answer: 2