LPS-induced LKB1 loss via proteasome-dependent degradation.
A, real-time PCR quantification of LKB1 mRNA levels in RAW 264.7 cells treated with LPS (100 ng/ml) for different time periods (n = 3). B, RAW 264.7 cells were treated with cycloheximide (CHX; 10 μm) in the presence or absence of LPS (100 ng/ml) for the indicated time periods. C, quantification of LKB1 protein levels as in B (n = 3). D, RAW 264.7 cells were treated with or without LPS for 16 h, and whole cell lysates were immunoprecipitated (IP) with anti-LKB1 antibodies and stained with anti-ubiquitin (Ub) or anti-LKB1 antibodies. The blot is representative of three blots from three individual experiments. IB, immunoblot. E, RAW 264.7 cells were treated with or without LPS (100 ng/ml) and different concentrations of MG132 for 24 h. The blot is representative of three blots from three individual experiments.