The conversion mechanism of GTP to cGMP by guanyl cyclase is shown below:

Figure 6: Regulatory Pathway of cGMP

 

Interesting facts:

1. Cyclic GMP is synthesized from the nucleotide GTP using the enzyme guanylyl cyclase .
2. Cyclic GMP serves as the second messenger for atrial natriuretic peptide (ANP), nitric oxide (NO), the response of the rods of the retina to light.
3. Some of the effects of cGMP are mediated through Protein Kinase G (PKG) a cGMP-dependent protein kinase that phosphorylates target proteins in the cell.