STAMBP (AMSH) was identified as an interacting partner of the SH3 domain of STAM (Tanaka et al. 1999) and later characterized as a Zn2+-dependent ubiquitin isopeptidase with a substrate preference for Lys-63-linked polyubiquitin chains (McCullough et al. 2004, 2006). At the N terminus STAMBP contains a nuclear localization signal and a microtubule-interacting and transport (MIT) domain that can interact with several chromatin-modifying proteins that are components of the Endosomal sorting complex required for transport (ESCRT) III complex (Sierra et al. 2010). STAMBP binds clathrin heavy chains, which anchors it to endosomes (McCullough et al. 2006, Nakamura et al. 2006) and contains a STAM-interacting motif that binds the SH3 domain of STAM, stimulating the deubiquitinating activity of STAMBP (McCullough et al. 2006, Kim et al. 2006, Sierra et al. 2010).