HeLa cells were either mock-transfected (-) or transfected (+) with siRNA against MAPKAP-K2, siRNA against MAPKAP-K3 or siRNA against both MAPKAP-K2 and MAPKAP-K3 (+) as indicated. The HeLa cells were then left untreated or exposed for 30 min to 10 μg/ml anisomycin. The HeLa cells were lysed, then 30 μg of protein was separated by SDS-PAGE, transferred to nitrocellulose membrane and blotted with the appropriate antibody. The upper panel was probed with the anti-Nogo B Ser 107 phospho-specific antibody [S444A] and the lower panel with the anti-Nogo B antibody. Binding of the primary antibody was detected using rabbit peroxidase conjugated anti- sheep IgG antibody (1 in 10, 000 dilution, Pierce) followed by enhanced chemiluminescence (ECL, Amersham).