Figure 1.

Treatment of 3T3-L1 adipocytes with BoNT D blocks insulin-stimulated GLUT4–vesicle translocation to the plasma membrane. (A) SLO-permeabilized 3T3-L1 adipocytes were pretreated for 20 min with buffer alone (control) or buffer containing 100 nM BoNT D or BoNT C, followed by an additional 10-min incubation with insulin. Plasma membrane sheets were then prepared and GLUT4 was detected by immunofluorescence. (B) Following treatment of permeabilized cells with buffer alone (−) or BoNT D (+), an LDM subcellular membrane fraction was prepared and LDM-resident proteins were examined by immunoblot analysis using antisera against the proteins indicated.