• Register
Forgot Password

If you have forgotten your password you can enter your email here and get a temporary password sent to your email.


Leaving Community

Are you sure you want to leave this community? Leaving the community will revoke any permissions you have been granted in this community.


AMSH is an endosome-associated ubiquitin isopeptidase.

The JAMM (JAB1/MPN/Mov34 metalloenzyme) motif has been proposed to provide the active site for isopeptidase activity associated with the Rpn11/POH1 subunit of the 19S-proteasome and the Csn5-subunit of the signalosome. We have looked for similar activity in associated molecule with the SH3 domain of STAM (AMSH), a JAMM domain-containing protein that associates with the SH3-domain of STAM, a protein, which regulates receptor sorting at the endosome. We demonstrate isopeptidase activity against K48-linked tetraubiquitin and K63-linked polyubiquitin chains to generate di-ubiquitin and free ubiquitin, respectively. An inactivating mutation (D348A) in AMSH leads to accumulation of ubiquitin on endosomes and the concomitant stabilization of a ubiquitinated form of STAM, which requires an intact ubiquitin interaction motif (UIM) within STAM. Short interfering RNA knockdown of AMSH enhances the degradation rate of EGF receptor (EGFR) following acute stimulation and ubiquitinated EGFR provides a substrate for AMSH in vitro. We propose that AMSH is a deubiquitinating enzyme with functions at the endosome, which oppose the ubiquitin-dependent sorting of receptors to lysosomes.

Pubmed ID: 15314065


  • McCullough J
  • Clague MJ
  • UrbĂ© S


The Journal of cell biology

Publication Data

August 16, 2004

Associated Grants


Mesh Terms

  • Amino Acid Motifs
  • Binding Sites
  • Carrier Proteins
  • Catalysis
  • Down-Regulation
  • Endopeptidases
  • Endosomal Sorting Complexes Required for Transport
  • Endosomes
  • Glutathione Transferase
  • Green Fluorescent Proteins
  • HeLa Cells
  • Humans
  • Hydrogen-Ion Concentration
  • Luminescent Proteins
  • Lysosomes
  • Microscopy, Fluorescence
  • Models, Biological
  • Mutation
  • Plasmids
  • Precipitin Tests
  • Protein Binding
  • Protein Structure, Tertiary
  • RNA, Small Interfering
  • Receptor, Epidermal Growth Factor
  • Recombinant Fusion Proteins
  • Recombinant Proteins
  • Time Factors
  • Ubiquitin
  • Ubiquitin Thiolesterase
  • Ubiquitin-Protein Ligases
  • src Homology Domains