Structural basis of E2-25K/UBB+1 interaction leading to proteasome inhibition and neurotoxicityKo, S., Kang, G.B., Song, S.M., Lee, J.-G., Shin, D.Y., Yun, J.-H., Sheng, Y., Cheong, C., Jeon, Y.H., Jung, Y.-K., Arrowsmith, C.H., Avvakumov, G.V., Dhe-Paganon, S., Yoo, Y.J., Eom, S.H., Lee, W.
(2010) J Biol Chem 285: 36070-36080
- PubMed: 20826778
- DOI: https://doi.org/10.1074/jbc.M110.145219
- Primary Citation of Related Structures:
- PubMed Abstract:
E2-25K/Hip2 is an unusual ubiquitin-conjugating enzyme that interacts with the frameshift mutant of ubiquitin B (UBB(+1)) and has been identified as a crucial factor regulating amyloid-β neurotoxicity. To study the structural basis of the neurotoxicity mediated by the E2-25K-UBB(+1) interaction, we determined the three-dimensional structures of UBB(+1), E2-25K and the E2-25K/ubiquitin, and E2-25K/UBB(+1) complex. The structures revealed that ubiquitin or UBB(+1) is bound to E2-25K via the enzyme MGF motif and residues in α9 of the enzyme. Polyubiquitylation assays together with analyses of various E2-25K mutants showed that disrupting UBB(+1) binding markedly diminishes synthesis of neurotoxic UBB(+1)-anchored polyubiquitin. These results suggest that the interaction between E2-25K and UBB(+1) is critical for the synthesis and accumulation of UBB(+1)-anchored polyubiquitin, which results in proteasomal inhibition and neuronal cell death.
Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749, Korea.