Autophagy genes are required for lifespan extension in calcineurin defective C. elegans strains

Abstract

Autophagy, the word derived from Greek language, meaning auto - self and phagy - to eat. The process of autophagy is evolutionary conserved in all eukaryotic organisms, ranging from yeasts to human. Various reports suggest that lifespan extension is dependent on autophagic pathways. A recent study showed an extended lifespan in the calcineurin mutants of C. elegans. Calcineurin (CaN) is a serine/threonine phosphatase, activated by Ca2+/calmodulin (Ca2+/CaM). CaN is known to regulate various cellular responses in different organisms. In this study, we report that lifespan extension in calcineurin mutants is mediated through autophagy. In addition, we found two essential autophagy genes (bec-1 and atg-7) are required for the lifespan extension in calcineurin null mutant [cnb-1(jh103)]. Thus, for the first time we suggest that autophagy is required for the regulation of C. elegans lifespan, not only by insulin signaling and dietary restriction, but also through calcineurin pathway.