protein complementation assay mammalian protein protein interaction trap MI:0231 mappit PSI-MI The MAPPIT(mammalian protein-protein interaction Trap) is a screening method for protein-protein interaction in mammalian cells, based on the reconstitution of a membrane STAT (signal transducers and activators of transcription) receptor. The bait protein is fused to a STAT recruitment-deficient receptor and the prey protein to a functional STAT recruitment sites. In such a configuration, a given baitprey interaction restores a STAT-dependent responses leading to the expression of a reporter gene. This system, enable to demonstrate not only protein interaction but also modification-independent and tyrosine phosphorylation- dependent interactions.