Figure 3. Analysis of protein phosphorylation by Western blot analysis. Human gingival fibroblasts were stimulated with LPS from Porphyromonas gingivalis (P-LPS) in the presence or absence of anti-CD14 monoclonal antibody (anti-CD14 mAb). (A) The cells were subjected to Western blotting with anti-phosphotyrosine monoclonal antibody. (B) The immunoprecipitate was analyzed with anti-mitogen-activated protein kinase (MAPK: ERK2 and ERK1) kinase monoclonal antibody (Wang et al., 1996, 1998). The lanes are as follows: non-stimulated cells (lane 1), LPS-stimulated (lane 2), anti-CD14 mAb (lane 3), and both LPS and anti-CD14 mAb (lane 4).