Translocation of diacylglycerol kinase in response to chemotactic peptide and phorbol ester in neutrophils.

When neutrophils were stimulated by the chemotactic peptide, fMLP, a rapid, transient increase in the activity of diacylglycerol(DG) kinase in the membrane fraction was detected. DG kinase in cytosol, on the contrary, showed a transient decrease. The total activity in homogenates was not affected. Tetradecanoylphorbol acetate(TPA) and 1-oleoyl-2-acetylglycerol(OAG) also caused an increase in DG kinase activity in the membrane fraction. Km value of DG kinase in membranes was not changed by the treatment of fMLP or TPA, though Vmax was increased. Considering these results, DG kinase may translocate from cytosol to membranes on stimulation by fMLP, TPA or OAG in neutrophils. The translocation may play important roles in regulation of protein kinase C activity, since DG kinase competes with protein kinase C for DG, which is formed by receptor-activation.