Design and use of a mammalian protein-protein interaction trap (MAPPIT)

Identifying the interaction partners of a protein is a straightforward way to gain insight into the protein's function and to position it in an interaction network such as a signal transduction pathway. Various techniques have been developed to serve this purpose, and some are specifically designed to study posttranslational modifications in mammalian proteins and to clarify their normal physiological context. However, several intrinsic constraints limit the use of these technologies, and most are not suitable for screening for new interacting partners. In the Mammalian Protein-Protein Interaction Trap (MAPPIT) Protocol described here, knowledge of cytokine receptor signaling has been used to design a versatile genetic tool that can be used analytically and for detection of new protein-protein interactions in mammalian cells.