This gene is a member of the type IV, cyclic AMP (cAMP)-specific, cyclic nucleotide phosphodiesterase (PDE) family. The encoded protein regulates the cellular concentrations of cyclic nucleotides and thereby play a role in signal transduction. Altered activity of this protein has been associated with schizophrenia and bipolar affective disorder. Alternative splicing and the use of alternative promoters results in multiple transcript variants encoding different isoforms. [provided by RefSeq, Jul 2014],alternative products:Additional isoforms seem to exist,catalytic activity:Adenosine 3′,5′-cyclic phosphate + H(2)O = adenosine 5′-phosphate.,enzyme regulation:Inhibited by rolipram.,function:May be involved in mediating central nervous system effects of therapeutic agents ranging from antidepressants to antiasthmatic and anti-inflammatory agents.,pathway:Purine metabolism; cAMP degradation; AMP from cAMP: step 1/1.,similarity:Belongs to the cyclic nucleotide phosphodiesterase family.,tissue specificity:Expressed in brain, heart, lung and skeletal muscle.,