Figure 2. The L1–3 region of the C/EBPδ leucine zipper is required for ubiquitination.

(a) Schematic representation of C/EBPδ constructs. (b) In vivo ubiquitination of C/EBPδ mutants containing lysine deletions. The ‘–’ lane designates co-transfection of HA-Ub plus empty vector control. The bottom panel shows the protein levels of transfected C/EBPδ constructs. Asterisks denote the truncated proteins generated by using internal start codons. (c) Lys²³² is not the target lysine residue for C/EBPδ ubiquitination. Ubiquitination of ΔAD, ΔL1–3 and ΔL1–3K232R is presented (upper panel). The ‘–’ lane designates co-transfection of HA-Ub plus empty vector control. The bottom panel shows the protein levels of transfected C/EBPδ constructs.