Phosphodiesterase 7A (PDE7A)

HCP1 had an amino acid sequence related to the sequences of the catalytic domains of all cyclic nucleotide PDEs. It is a high-affinity cAMP-specific PDE that does not share other properties of the cAMP-specific PDE family, however. The PDE activity of HCP1 was not sensitive to cGMP or other inhibitors of the cGMP-inhibitable PDEs. The biochemical and pharmacologic properties of HCP1 suggested to Michaeli et al. (1993) that it is a member of a previously undiscovered cyclic nucleotide PDE family, which they designated as family VII. Northern blot analysis indicated the presence of high levels of an HCP1 mRNA in human skeletal muscle.PDE7A variants A1 and A2 are expressed in human umbilical vein endothelial cells (HUVEC). Their steady state level decreased following treatment with TNFA.