Molecular Cloning and Expression of Human cGMP-Binding cGMP-Specific Phosphodiesterase (PDE5)

A human PDE5 cDNA has been isolated which contains an open reading frame encoding an 875 amino acid, 100,012 Da polypeptide, the expression of which yields a protein of the predicted size and is capable of hydrolyzing cGMP. The deduced amino acid sequence is very similar (95%) to that of bovine PDE5, and comprises a conserved cGMP-binding domain and catalytic domain. Northern analysis reveals a major and minor transcript of ∼9 kb and ∼8 kb respectively, thus indicating the existence of at least two splice variants, the major form being readily detected in bladder, colon, lung, pancreas, placenta, prostate, small intestine, and stomach.