Bone marrow derived macrophages from wild-type and MAPKAP-K2-deficient mice were pre-treated or not for 15 min with 10 μM SB 203580 (SB) and either left untreated or stimulated with 50 ng/ml LPS for 1 hr. The cells were lysed, separated by SDS- PAGE, transferred to nitrocellulose membrane and blotted with the appropriate antibody. The upper panel was probed with the anti-hnRNP A0 Ser84 phospho-specific antibody [S729A] and the lower panel with the anti-hnRNP A0 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).