AMPK destabilizes C/EBPβ via T188 dephosphorylation.

<p>A: MIN6 cells were co-transfected with expression vectors for C/EBPβ, T188A-mutant C/EBPβ, or T188E-mutant and mock or DN-AMPK (leftmost and second right). Quantitation of C/EBPβ expression is normalized to β-actin (second left and rightmost). B: MIN6 cells were co-transfected with expression vectors for C/EBPβ or T188A-mutant C/EBPβ, T188E-mutant and mock or CA-AMPK (leftmost and second right). Quantitation of C/EBPβ expression is normalized to β-actin (second left and rightmost). C, D: MIN6 cells were transfected with expression vectors for C/EBPβ or HA-tagged C/EBPβ. The cells were pretreated with 1 μg/mL CHX and incubated with 1 μg/mL CHX and 1 μM thapsigargin. C/EBPβ (C) or T188A-mutant C/EBPβ (D) expression was measured by western blot analysis (C; left and middle, D; left). Quantitation of C/EBPβ expression is normalized to β-actin (right). Data are means ± SE of 3 independent experiments. *<i>P</i> < 0.05, **<i>P</i> < 0.01. n.s., not significant.