ऑटोफेगी

Every cell in our body is equipped with a form of housecleaning machinery called autophagy. Autophagy is universally present in all cells — from yeast to humans. During nutrient starvation, autophagic processes promote cell survival by degrading superfluous cytoplasmic proteins and organelles. The cytoplasmic cargo is captured by a cup-shaped structure called the phagophore, which elongates and expands to form vesicles known as autophagosomes. These autophagosomes fuse with lysosomes, where lysosomal proteases degrade the cargo into basic building blocks for recycling.

Autophagy not only clears superfluous and unwanted cellular components but also plays a vital role in degrading several intracellular pathogens, including bacteria (Salmonella, Shigella, Mycobacterium, Group A Streptococcus, etc.) and viruses (herpes simplex virus, HIV, etc.).

Furthermore, autophagy serves a neuroprotective function by clearing large aggregates of mutant polyubiquitylated proteins that are resistant to proteasomal degradation. Beyond neurodegenerative and infectious diseases, autophagy has been implicated in heart diseases, atherosclerosis, certain myopathies, innate and adaptive immune responses, Crohn's disease, and cancer.