Figure 4.

JMY is regulated by a proteasome-dependent pathway. (A) Endogenous JMY was detected in wild-type (WT) and p53^−/−/Mdm2^−/− mouse embryonic fibroblasts (MEFs) using the JMY L-16 antibody; proliferating-cell nuclear antigen (PCNA) was used as a loading control. (B) The fold increase in JMY level in p53^−/−/Mdm2^−/− compared with WT MEFs. (C) WT or p53^−/−/Mdm2^−/− MEFs were treated with 50 μg/ml cyclohexamide (chx) for the times indicated, and cell extracts immunoblotted with the JMY antibody L-16. PCNA was used as a loading control. (D) The relative JMY levels in WT MEFs as a percentage of total JMY in p53^−/−/Mdm2^−/− MEFs. IB, immunoblotting.