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 approximately 9 kb and approximately 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.

Copyright 1998 Academic Press.