Figure 2.

D4 induces the appearance of apoptotic cell death markers in Jurkat cells. Jurkat cells were cultured for the indicated time periods in the presence of 10 μg/ml anisomycin (An), 0.15% H₂O₂, or 1% D4. Cell lysates were analyzed by western blotting using patient sera reactive with (A) U1-70K or (B) Topo I. Note that the anti-U1-70K serum is also reactive with the Sm-B/B’ proteins. The apoptotic cleavage products of U1-70K and Topo I are indicated with arrowheads (40 K and 70 K, respectively); the necrotic cleavage product of Topo I is indicated with an asterisk (45 K). The positions of molecular weight markers are indicated on the left. Note that both panels were composed with different (cropped) parts of the same blot, indicated by the dividing lines, as further illustrated in the Supplementary Information. The intensity of the major cleavage products of U1-70K (40 K) and of Topo I (45 K) was quantified and normalized based upon the Sm-B/B’ signals. a.u.: arbitrary units.