2.4 The role of OPTN in lysosome quality control
Lysosomes are organelles central to degradation and recycling processes in animal cells. In autophagy, autophagosome fuses with a lysosome containing degrading enzymes and leads to the digestion of the autophagosome content. Therefore, although lysosomes often appear as autolysosome in autophagy, the normal function of lysosomes is very important to ensure that autophagy proceeds without a hitch. Claudioet al . using high-resolution and live-cell CLEM in AS-stimulated microglial cells demonstrated that both TBK1 and OPTN are recruitment to ubiquitylated lysosomes to handle with lysosomal quality impairment and restore lysosomal quality control by autophagy, which also called lysophagy named by autophagy substrate(Bussi et al. , 2018). In general, autophagy induction is frequently associated by up-regulated hydrolase synthesis and increased lysosome biogenesis(Ghavami et al. , 2014). When lysosomes are out of stabilizing or their function is impaired, the autophagy inhibitors tend to lessen the stress of autophagic on dysfunctional lysosomes by reducing the delivery of autophagic cargo rather than through an excessively aggressive autophagy process (Ghavami et al. , 2014). Therefore, the normal function of lysosomes is important for autophagy.