Fbxw7α- and GSK3-mediated degradation of p100 is a pro-survival mechanism in multiple myeloma.

Fbxw7α is a member of the F-box family of proteins, which function as the substrate-targeting subunits of SCF (Skp1/Cul1/F-box protein) ubiquitin ligase complexes. Using differential purifications and mass spectrometry, we identified p100, an inhibitor of NF-κB signalling, as an interactor of Fbxw7α. p100 is constitutively targeted in the nucleus for ...
proteasomal degradation by Fbxw7α, which recognizes a conserved motif phosphorylated by GSK3. Efficient activation of non-canonical NF-κB signalling is dependent on the elimination of nuclear p100 through either degradation by Fbxw7α or exclusion by a newly identified nuclear export signal in the carboxy terminus of p100. Expression of a stable p100 mutant, expression of a constitutively nuclear p100 mutant, Fbxw7α silencing or inhibition of GSK3 in multiple myeloma cells with constitutive non-canonical NF-κB activity results in apoptosis both in cell systems and xenotransplant models. Thus, in multiple myeloma, Fbxw7α and GSK3 function as pro-survival factors through the control of p100 degradation.
Mesh Terms:
Cell Cycle Proteins, Cell Survival, F-Box Proteins, Glycogen Synthase Kinase 3, HEK293 Cells, HeLa Cells, Humans, Multiple Myeloma, NF-kappa B p52 Subunit, Tumor Cells, Cultured, Ubiquitin-Protein Ligases
Nat. Cell Biol.
Date: Apr. 01, 2012
Download Curated Data For This Publication
139139
Switch View:
  • Interactions 24