| In this work , we show that STAM 1 and STAM 2 , as well as an endocytic regulator protein , Eps 15 , can be co immunoprecipitated with Hrs both from membrane and cytosolic fractions and that recombinant Hrs , STAM1 / STAM2 , and Eps 15 form a ternary complex . ^^^ Moreover , STAM 2 , like Hrs and Eps 15 , binds ubiquitin , and Hrs , STAM 2 , and Eps 15 colocalize with ubiquitinated proteins in clathrin containing endosomal microdomains . ^^^ The localization of Hrs , STAM 2 , Eps 15 , and clathrin to endosome membranes is controlled by the AAA ATPase mVps 4 , which has been implicated in multivesicular body formation . ^^^ |