Figure 5.

Absence of an effect of mutant Drp1 on the endocytic pathway. The function of the endocytic pathway was monitored by following LDL uptake. Cells transfected with the indicated Drp1 or dynamin constructs were incubated at 37°C in serum-free medium with Bodipy-LDL. After 25 min the cells were washed and fixed for staining with anti-Drp1 or anti-dynamin antibody. Cells that overexpress mutant or wild-type Drp1 or dynamin were identified by double labeling with anti-Drp1 or anti-dynamin antibody as indicated by the gray outlines. LDL does not appear in the lysosomes of 70% of cells transfected with mutant dynamin (Dyn1-K44A), demonstrating the validity of this approach. There was no detectable difference in the distribution of lysosomes in cells transfected with wild-type Drp1 (Drp1-wt), the K38A mutant (Drp1-K38A), or in untransfected cells, showing that mutant Drp1 does not affect the endocytic pathway.