Figure 4. Effect of DMS on in vitro SphK2 activity.

Affinity-purified recombinant Sphk2 expressed in insect cells was assayed for its ability to phosphorylate sphingosine (100 μM (A, C, D), 0.2 μM (B, E) or absence (C) ) using [γ-³²P]ATP in the presence of various concentrations of DMS as specified. After termination of the reaction, radio-labeled S1P was separated by thin-layer chromatography followed by autoradiography. One of the representative data from three independent experiments is shown (A). The bands corresponding to S1P were quantitated using a Fujix Bio-Imaging Analyzer. Data are means ± s.e.m. from 3 independent experiments (B).