We have established a highly sensitive functional screen for the isolation of cDNAs encoding cAMP phosphodiesterases (PDEs) by complementation of defects in a Saccharomyces cerevisiae strain lacking both endogenous cAMP PDE genes, PDE1 and PDE2. Three groups of cDNAs corresponding to three distinct human genes encoding cAMP-specific PDEs were isolated from a human glioblastoma cDNA library using this functional screen. Two of these genes are closely related to the Drosophila dunce cAMP-specific PDE. The third gene, which we named HCP1, encoded a novel cAMP-specific PDE. HCP1 has an amino acid sequence related to the sequences of the catalytic domains of all cyclic nucleotide PDEs. HCP1 is a high affinity cAMP-specific PDE (Km = 0.2 microM) that does not share other properties of the cAMP-specific PDE family, i.e. extensive sequence homology to the Drosophila dunce cAMP PDE and sensitivity to rolipram and R020-1724. The PDE activity of HCP1 is not sensitive to cGMP or other inhibitors of the cGMP-inhibitable PDEs, such as milrinone. The biochemical and pharmacological properties of HCP1 suggest that it is a member of a previously undiscovered cyclic nucleotide PDE family. Northern blot analysis indicates that high levels of HCP1 mRNA are present in human skeletal muscle.

• PMID: 8389765
• PubMed
• PubTator

Reference Type

Comparative Study | Journal Article | Research Support, Non-U.S. Gov't | Research Support, U.S. Gov't, P.H.S.

Authors

Michaeli T, Bloom TJ, Martins T, Loughney K, Ferguson K, Riggs M, Rodgers L, Beavo JA, Wigler M

Primary Lit For

Additional Lit For

Review For