Figure 2. UPS-dependent regulation of Bcl-2 family protein levels.
The UPS regulates the ratio of pro- and anti-apoptotic proteins in Bcl-2 family. Distinct E3 Ub ligases (E3) are either activated or inhibited upon induction of apoptosis. This leads to a regulated degradation of anti-apoptotic Bcl-2 proteins (e.g. Mcl-1 or Bcl-2) or stabilization of pro-apoptotic Bcl-2 family proteins (e.g. Bim or Baxβ) and thereby activation of downstreamcell death program. Red arrows: depict activation of respective proteins by specific E3 Ub ligases (E3). Green “Ts” depict inhibition of respective proteins by specific E3 Ub Ligases (E3). *Usp9x is a deubiquitinase (DUB) that inhibits Mcl-1 degradation. For details see text and Table1.