FIGURE 7.

Model for BMXΔN degradation. Our proposed model is that the caspase-generated BMXΔN is recognized by the degenerate UBR1 and UBR2 E3 ubiquitin ligases. UBR1/2 recognize the N-terminal tryptophan of BMXΔN, which then ubiquitinates the protein, targeting it to the proteasome for degradation and thus attenuating its pro-apoptotic function. Phosphorylation of BMXΔN at tyrosine 566 is required its pro-apoptotic function and relatively inhibits its degradation by the N-end rule pathway. PH, pleckstrin homology domain.