The unique N-terminal domain of the cAMP phosphodiesterase PDE4D4 allows for interaction with specific SH3 domains

Of the five PDE4D isoenzymes, only the PDE4D4 cAMP specific phosphodiestera se mas able to bind to SH3 domains. Only PDE4D4 and PDE4A5, but not any oth er PDE4A, B, C and D isoforms expressed in rat brain, bound to src, lyn and fyn kinase SH3 domains, Purified PDE4D4 could bind to purified lyn SH3. PD E4D4 and PDE4A5 both exhibited selectivity for binding the SH3 domains of c ertain proteins. PDE4D4 did not bind to WW domains. We suggest that an impo rtant function of the unique N-terminal region of PDE4D4 may be to allow fo r association with certain SH3 domain-containing proteins, (C) 1999 Federat ion of European Biochemical Societies.