Figure 6

Ratjadone A protects CRM1 from proteolysis. Lysates from Rev-transfected 293 T cells were mock-treated with DMSO or incubated with 200 nM ratjadone A or leptomycin B and digested with Pronase. Samples were loaded on a SDS-PAGE gel and developed by Western Blot (see Materials and methods). Lane 1: undigested DMSO control; Lane 2: digested DMSO control; Lane 3: digested sample incubated with RaTA; Lane 4: digested sample incubated with LMB. Percentages of protection relative to undigested controls are shown below the protein bands. Both RaTA and LMB protect CRM1 (upper row) but not Rev (middle row) from degradation. Tubulin was used as a loading control (lower row). The drug solvent concentration (0.1% DMSO) in every sample was constant. Abbreviations: RAT = Ratjadone A; LMB = Leptomycin B; DMSO = dimethyl sulfoxide; n.a. = not applicable.