• Purity

  >90%, by SDS-PAGE under reducing conditions and visualized by Colloidal Coomassie® Blue stain

• Activity

  Reaction conditions for stimulation of AMSH will need to be optimized for each specific application.  Binds AMSH protein with Kd = ~7 µM. In     in vitro assays containing 200 nM AMSH, a ~10-fold increase in the rate of hydrolysis of K63-linked diubiquitin FRET substrate was achieved upon the addition of STAM. Half-maximal increase occurred at 0.4 μM STAM.

• Source

  E. coli-derived

• Accession #

• Predicted Molecular Mass

  60 kDa

Background: STAM-1

Signal Transducing Adaptor Molecule-1 (STAM-1) is a member the STAM family of adaptor molecules. This ubiquitously expressed protein is 540 amino acids (aa) in length with a predicted molecular weight of 59.18 kDa. Human STAM-1 shares 91% and 92% aa sequence identity with the rat and mouse orthologs, respectively. It contains multiple domains including a VHS domain (aa 16-143) and a Ubiquitin-interacting motif (aa 171-190), both of which bind ubiquitinated proteins, a SH3 domain (aa 210-269) that associates with the zinc metalloprotease STAMBP, and an ITAM domain (aa 370-387), which contains a Hrs-binding site and interacts with Janus kinases (Jaks) (1-6). STAM-1 is involved in downstream signaling stimulated by cytokines and growth factors. It is tyrosine phosphorylated by Jaks in response to a variety of cytokines including IL-2, IL-3, IL-4, IL-7, GM-CSF, EGF, and PDGF, and has been shown to induce DNA synthesis and MYC expression (1,2,5). Additionally, STAM-1 has been shown to regulate CXCR4 signaling and appears to be important for T cell development and survival (7,8). Besides its role in signal transduction, STAM-1 may also be important for the regulation of endocytic membrane trafficking. It associates with Hrs to form the endosomal sorting complex required for transport-0 (ESCRT-0) complex, which binds to ubiquitinated membrane proteins on early endosomes and directs them to the ESCRT-1 complex for lysosomal degradation (6, 9-11). STAM-1 has also been shown to interact with coat protein II complexes and function in trafficking vesicles from the endoplasmic reticulum to the Golgi apparatus (12). This full-length recombinant human protein has no intrinsic deubiquitinase activity but is useful in stimulating the in vitro activity of the JAMM-class deubiquitinase AMSH.

• References:

1. Takeshita, T.         et al. (1996) Biochem. Biophys. Res. Commun.         225:1035.

2. Takeshita, T.         et al. (1997) Immunity         6:449.

3. Asao, H.         et al. (1997) J. Biol. Chem.         272:32785.

4. Tanaka, N.         et al. (1999) J. Biol. Chem.         274:19129.

5. Lohi, O. & V.P. Lehto (2001) FEBS Lett.         508:287.

6. Mizuno, E.         et al. (2003) Mol. Biol. Cell         14:3675.

7. Yamada, M.         et al. (2002) Mol. Cell. Biol.         22:8648.

8. Malik, R.         et al. (2012) J. Biol. Chem.         287:9013.

9. Bache, K.G.         et al. (2003) J. Biol. Chem.         278:12513.

10. Mizuno, E.         et al. (2004) J. Biochem.         135:385.

11. Ren, X. & J.H. Hurley (2010) EMBO J.         29:1045.

12. Rismanchi, N.         et al. (2009) Traffic         10:201.

• Long Name:

  Signal Transducing Adaptor Molecule 1

• Entrez Gene IDs:

  8027 (Human); 20844 (Mouse); 498798 (Rat)

• Alternate Names:

  DKFZp686J2352; HSE1 Homolog; signal transducing adapter molecule 1; signal transducing adaptor molecule (SH3 domain and ITAM motif) 1; STAM; STAM1; STAM-1; STAM1STAM-1