| Multi PDZ domain protein 1 ( MUPP 1 ) is concentrated at tight junctions through its possible interaction with claudin 1 and junctional adhesion molecule . ^^^ Using the yeast two hybrid system , we identified ZO 1 and MUPP 1 ( multi PDZ domain protein 1 ) as binding partners for the COOH terminus of claudin 1 . ^^^ Multi PDZ domain protein 1 ( MUPP 1 ) is concentrated at tight junctions through its possible interaction with claudin 1 and junctional adhesion molecule . ^^^ In vitro binding assays with recombinant MUPP 1 confirmed the interaction between MUPP 1 and claudin 1 and identified PDZ 10 as the responsible domain for this interaction . ^^^ |