The protein encoded by this gene belongs to the cyclic nucleotide phosphodiesterase (PDE) family, and PDE4 subfamily. This PDE hydrolyzes the second messenger, cAMP, which is a regulator and mediator of a number of cellular responses to extracellular signals. Thus, by regulating the cellular concentration of cAMP, this protein plays a key role in many important physiological processes. Alternatively spliced transcript variants encoding different isoforms have been described for this gene.[provided by RefSeq, Jul 2011],catalytic activity:Adenosine 3,5-cyclic phosphate + H(2)O = adenosine 5-phosphate.,enzyme regulation:Inhibited by rolipram.,pathway:Purine metabolism, cAMP degradation, AMP from cAMP: step 1/1.,similarity:Belongs to the cyclic nucleotide phosphodiesterase family.,tissue specificity:Expressed in various tissues but not in cells of the immune system.,
