XMD17-109 (ERK5-IN-1) is a new selective ERK-5 inhibitor (EC50: 4.2 uM, HEK293 cells).

At the cellular level, ERK5-IN-1 inhibits endothelial growth factor-induced ERK5 autophosphorylation (EC50: 90 nM). It also effectively inhibits the biochemical properties of ERK5 (IC50: 162 nM).

HeLa cells are maintained in DMEM supplemented with 10% FBS, 2 mM?l-glutamine, 50 U/mL penicillin G, and 50 μg/mL streptomycin. Before use HeLa cells are serum starved for 16 h in DMEM supplemented with 2 mM?l-glutamine, 50 U/mL penicillin G, and 50 μg/mL streptomycin. HeLa cells are then incubated with ERK5-IN-1 at the indicated concentrations for 1 h prior to stimulation with 0.5mol/Lsorbitol for 30 min. Cells are lysed in Triton lysis buffer (50 mM Tris-HCl, pH 7.5, 1 mM EGTA, 1 mM EDTA, 1 mM sodium orthovanadate, 50 mM sodium fluoride, 1 mM sodium pyrophosphate, 0.27mol/Lsucrose, 1 μM microcystin-LR, 1% (v/v) Triton X-100, 0.1% (v/v) 2-mercaptoethanol) and 20 μg of protein loaded per well. Samples are run on 8% polyacrylamide gels using standard methods. Proteins are transferred onto nitrocellulose membranes and specific proteins detected by immunoblotting.