Overview of Autophagy

Autophagy plays a direct or indirect role in health and disease. A simplifi ed defi nition of autophagy is that it is an exceedingly complex process which degrades modified, superfluous (surplus), or damaged ­cellular macromolecules and whole organelles using hydrolytic enzymes in the lysosomes. It consists of sequential steps of induction of autophagy, formation of autophagosome precursor, formation of ­autophagosomes, fusion between autophagosome and lysosome, degradation of cargo contents, efflux transportation of degraded products to the cytoplasm, and lysosome reformation. This chapter discusses specific functions of autophagy, the process of autophagy, major types of autophagy, influences on autophagy, and the role of autophagy in disease, immunity, and defense