Fig. 3. MIB2 ubiquitylates cFLIP_L in a RING domain-dependent manner.

a Domain structures of MIB2 and their mutants. ZF, zinc finger; ANK, ankyrin repeats; R, RING finger domain. X indicates the RING finger mutants in which active cysteines at 900 and 977 are replaced by serines, including R1M (C900S), R2M (C977S), and R1MR2M (CC900/977SS). b HEK293 cells were transfected and analysed as Fig. 1c. c Deletion mutants of MIB2. Numbers indicate the amino acids included in the respective mutant. d HEK293 cells were transfected and analysed as in Fig. 1e. C8C/S indicates a protease-inactive mutant of caspase 8. Results are representative of two independent experiments (b, d).