Fig. 4.

Upstream kinase for ATF2 phosphorylation and expression. a ATF2 regulates the expression of CyclinD1. Western blot indicating the protein level of CyclinD1 in RBE cells where ATF-2 was stably or transiently depleted (*< 0.05, **< 0.01, ***< 0.001). b The cells were treated with 0, 1, 10, 20, 50, and 100 nM PTHLH for 4 h, and western blot was performed for ATF2, PTHLH and GAPDH (*< 0.05). c The cells were treated with 20 nM PTHLH for the indicated times, and western blot was performed for ATF2, PTHLH and GAPDH (*< 0.05, **< 0.01). d Western blot of the expression of ATF2, JNK and ERK1/2 protein and phosphorylation of JNK (Thr183/Thr185), ERK1/2 (T202/Y204), MKK4 (S257) and ATF-2 (Thr71) in the RBE cells (*< 0.05). e Cells were pre-treated with U0126 (10 μM) or SP600125 (20 μM) and then treated with 20 nM PTHLH for 4 h. Cell distribution was determined by flow cytometry (*< 0.05), and the expression of related proteins was determined by western blot (**< 0.01, ***< 0.001)