Ina search for genes regulated in response to cAMPwe have identified a newprotein, p76 RBE , whosemRNAand protein expression is enhanced in thyrocytes following thyrotropin stimulation of the cAMP transduction cascade. This protein presents important similarities with Rhophilin and contains different protein–protein interactionmotifs. The presence of HR1 and PDZ motifs as well as a potential PDZ binding domain motif suggests that p76 RBE could be implicated in targeting or scaffolding processes