Figure 4.

DdLIMP can localize to macropinosomes in wild-type Dictyostelium cells. Macropinosomes were labeled in growth medium by pulsing cells attached to coverslips with 5 mg/ml fixable TR-dextran for 2 min (C). Cells were fixed, permeabilized, and then incubated with antibodies to DdLIMP followed by the addition of FITC-conjugated secondary antibody (B). Cells were visualized with the use of an Olympus epifluorescence microscope, as described (Seastone et al., 1998, 1999). The large arrow points to a macropinosome (large vacuole in A) that is DdLIMP positive (B) and TR-dextran positive (C), and the small arrow points to one of a number of small DdLIMP-positive punctate structures.