Fig. 4. GTPγS binding and GTPase activities of RhoA polyaminated by DNT. The recombinant RhoA (5 μM) was treated with DNT (50 nM) in the presence of 250 μM spermidine and examined for GTPγS binding (A) and GTPase activities (B). (○), Control RhoA; (□), spermidine-linked RhoA. In (B), GAP-stimulated GTPase activities of control RhoA (•) and spermidine-linked RhoA (▪) were also determined. Three independent experiments were performed and representative results are shown.