Fig. 1.
BTX binds to GABAAβ3. (a) Rhodamine-BTX labels HEK 293 cells transfected with a plasmid encoding GABAΑR β3. Labeling is blocked by preincubation with unconjugated BTX. Untransfected cells are not labeled. (b and c) BTX specifically labels GABAAR β3-transfected CHO and N2a cells. (d) Labeling of GABAΑR β3-transfected cells by BTX and anti-GABAAR β3 antibody is coincident. Cells in a and d were stained live and then fixed; cells in b and c were fixed and permeabilized before staining. (Scale bars, 5 μm.)