Prominin-like, a homolog of CD133, interacts with ND20 to maintain mitochondrial function.

BACKGROUND

Prominin-like is a homolog of mammalian CD133, which is recognized as a biomarker for stem cells. The interacting proteins of CD133 and their biological functions remain elusive.

RESULTS

In this study, we using yeast two-hybrid assays, GST pull-down assay and co-immunoprecipitation (Co-IP) methods found that Prominin-like interacts with ND20, a subunit of mitochondrial respiratory complex I. Bioinformatics analysis suggests that Prominin-like is a six-transmembrane glycoprotein which localizes on cellular membranes. Immunostaining and mitochondrial fractionation indicate that Prominin-like could localize in the mitochondria. The knockdown of - in S2 cells resulted in transient mitochondrial dysfunctions as evidenced by reduced ATP production, elevated ROS generation and an accompanied reduction in mitochondrial proteins. Mitochondrial dysfunctions were detected in aged - mutant flies.

CONCLUSION

Our data indicates that Prominin-like acts to maintain mitochondrial function through its interaction with ND20 which, itself, is active in the mitochondrial electron transport chain. Our study provides insights into a novel molecular mechanism of - and suggests a similar function of CD133 in mammals.