3.4.3 Cyclic GMP
Cyclic GMP (cGMP) is a second messenger with many similarities to cAMP. It is synthesized from GTP by guanylyl cyclase, and degraded to 5´- GMP by cyclic GMP phosphodiesterases. Some of the targets of cGMP are analogous to those of cAMP: cGMP-dependent protein kinase (PKG), and cGMP-gated Na+ ion channels.
We have already discussed a type of receptor that employs cGMP for signal transfer. What type of receptor is it?
Receptors with intrinsic enzymatic activity with an intracellular guanylyl cyclase catalytic domain (Figure 23a).