Active ERK1/2 Protein Interacts with the Phosphorylated Nuclear Constitutive Active/Androstane Receptor (CAR; NR1I3), Repressing Dephosphorylation and Sequestering CAR in the Cytoplasm

The nuclear constitutive active/androstane receptor (CAR) is inactivated and sequestered in the cytoplasm when Thr-38 is phosphorylated. Here, we have demonstrated that activated ERK1/2 interacts with phosphorylated CAR to repress dephosphorylation of Thr-38. The phosphorylation-dependent interaction between CAR and ERK1/2 was examined by co-immunoprecipitation experiments of ectopically expressed FLAG-tagged CAR T38A and CAR T38D mutants with...