Abstract
Mouse SKD1 AAA ATPase is involved in the sorting and transport from endosomes; cells overexpressing a dominant-negative mutant, SKD1E235Q were defective in endosomal transport to both the plasma membranes and lysosomes (Yoshimori et al., 2000). In the present study, we demonstrated that overexpression of SKD1E235Q using an adenovirus delivery system caused a defect in autophagy-dependent bulk protein degradation. Morphological observations suggested that this inhibition of autophagy results from an impairment of autolysosome formation. SKD1E235Q overexpression also inhibited transport from endosomes to autophagosomes, an event normally occurring prior to fusion with lysosomes. These results indicate that SKD1-dependent endosomal membrane trafficking is required for formation of autolysosomes.
