Figure 6. Ectopic expression of active form of PKCδ facilitates ubiquitination of C/EBPα protein.

(A) NB4 cells were treated with or without 25 nM of NSC606985 for 12 hours and/or 10 µM MG132 for 5 hours before harvest. (B) After pretreatment for 2 hours in the presence or absence of 1 µM of rottlerin, NB4 cells were treated with or without 25 nM of NSC606985 for additional 12 hours. (C) HEK293T cells were transfected with C/EBPα, ubiquitin and other plasmids as indicated for 24 hours. Then, cells were treated with or without 20 µM MG132 for 5 hours before harvest. Cell lysates were co-immunoprecipitated with anti-C/EBPα antibody, and precipitates or total lysate (input) were detected by western blots for GFP, PKCδ, C/EBPα and ubiquitin.