| In attempt to shed light on schwannomin function , we have identified a novel coiled coil protein , SCHIP 1 , that specifically associates with schwannomin in vitro and in vivo . ^^^ Immunofluorescent staining of transiently transfected cells shows a partial colocalization of SCHIP 1 and schwannomin , beneath the cytoplasmic membrane . ^^^ Surprisingly , immunoprecipitation assays reveal that in a cellular context , association with SCHIP 1 can be observed only with some naturally occurring mutants of schwannomin , or a schwannomin spliced isoform lacking exons 2 and 3 , but not with the schwannomin isoform exhibiting growth suppressive activity . ^^^ Our observations suggest that SCHIP 1 interaction with schwannomin is regulated by conformational changes in schwannomin , possibly induced by posttranslational modifications , alternative splicing , or mutations . . ^^^ Cloning and characterization of SCHIP 1 , a novel protein interacting specifically with spliced isoforms and naturally occurring mutant NF 2 proteins . ^^^ |