Figure 8.

Expression of ATPase-defective hVPS4 affects cholesterol sorting. NRK cells were transfected with GFP-hVPS4(KQ) (A–H) or GFP-hVPS4(wt) (I–L) and examined by conventional fluorescence microscopy for GFP (green; A, E, and I), M6PR (red; B), lgp120 (red; F and J), and cholesterol (blue, filipin staining; C, G, and K). Merged images (D, H, and L) are shown. Examples of vacuoles that costain for GFP, marker, and filipin are indicated by arrows. Note that exposure conditions for filipin staining were identical in all samples. No increase in filipin staining was observed in the cell transfected with GFP-hVPS4(wt) relative to the neighboring untransfected cell.