Cellular autophagy process

Autophagy is an evolutionarily conserved cellular degradation process that targets cytoplasmic materials—including proteins, macromolecules, and unwanted organelles—for lysosome-dependent breakdown. It is essential for maintaining cellular homeostasis by removing damaged components and recycling nutrients during periods of stress such as starvation or hypoxia. There are three main types—macroautophagy (the most studied), microautophagy, and chaperone-mediated autophagy—each with distinct mechanisms but all serving the purpose of intracellular quality control. Autophagic dysfunction is implicated in various diseases including cancer, neurodegenerative disorders, infections, and aging-related conditions. The process involves several key steps: initiation by stress signals; nucleation via complexes like Beclin1-VPS34; elongation involving ATG proteins; fusion with lysosomes; followed by degradation/recycling of cargo. While critical for cell survival under adverse conditions, dysregulation can have pathological consequences.

Other names

AutophagyMacroautophagyMicroautophagyChaperone-mediated autophagy (CMA)