Hydrolyzes the second messenger cAMP, which is a key regulator of many important physiological processes (PubMed:18983167). May be involved in maintaining basal levels of the cyclic nucleotide and/or in the cAMP regulation of germ cell development (PubMed:18983167). Binding to RAF1 reduces RAF1 'Ser-259' inhibitory-phosphorylation and stimulates RAF1-dependent EGF-activated ERK-signaling (PubMed:23509299). Protects against cell death induced by hydrogen peroxide and staurosporine (PubMed:23509299). 3',5'-cyclic AMP + H2O = AMP + H(+) Binds 2 divalent metal cations per subunit. Site 1 may preferentially bind zinc ions, while site 2 has a preference for magnesium and/or manganese ions. Inhibited by dipyridimole. Insensitive to selective PDE inhibitors including rolipram and zaprinast as well as to the non-selective inhibitor, IBMX. Unaffected by cGMP. Purine metabolism; 3',5'-cyclic AMP degradation; AMP from 3',5'-cyclic AMP: step 1/1. Interacts with RAF1. The interaction promotes RAF1 activity. Expressed in most tissues except thymus and peripheral blood leukocytes. Highest levels in testis, ovary, small intestine and colon. Composed of a C-terminal catalytic domain containing two putative divalent metal sites and an N-terminal regulatory domain. Phosphorylated at Ser-359 by PKA under elevated cAMP conditions, this enhances catalytic activity. May be produced at very low levels due to a premature stop codon in the mRNA, leading to nonsense-mediated mRNA decay. May be produced at very low levels due to a premature stop codon in the mRNA, leading to nonsense-mediated mRNA decay. May be produced at very low levels due to a premature stop codon in the mRNA, leading to nonsense-mediated mRNA decay. Belongs to the cyclic nucleotide phosphodiesterase family. PDE8 subfamily. Wrong choice of CDS. Wrong choice of CDS. Wrong choice of CDS. Intron retention.