Figure 5.

Pin1 binding to Mcl-1 inhibits ubiquitination and degradation of Mcl-1. A, Pin1 binds Mcl-1 at T¹⁶³P. 293T cells were transfected with Mcl-1 wild type and mutants and were treated with 50 ng/ml anisomycin for 30 min to activate the endogenous JNK pathway. Lysates then were subjected to pulldown assays with GST or GST-Pin1. The Mcl-1 input controls are shown also. B, Pin1 binds Mcl-1 in vivo, and its binding to Mcl-1 decreases with injury more rapidly in the wild-type mice as compared with JNK3^−/− mice. The lysates were immunoprecipitated with Mcl-1 or the control IgG, and the bound Pin1 was probed. The levels of Pin1 and Mcl-1 are shown as controls. C, Quantification of the amount of Pin1 bound to Mcl-1 (n = 3). Asterisks represent the time points at which the two genotypes showed a statistical difference (Student's t test, p < 0.05). The difference at 1 h after injury was p = 0.08 (Student's t test).