| Using the cytoplasmic C terminus of synaptophysin as bait in a yeast two hybrid screen , we identified two synaptophysin binding proteins , Siah 1A and Siah 2 , which are rat homologues of Drosophila Seven in Absentia . ^^^ We demonstrated that Siah 1A and Siah 2 associate with synaptophysin both in vitro and in vivo and defined the binding domains of synaptophysin and Siah that mediate their association . ^^^ |