Figure 3.

Shown is an illustration demonstrating through which excessive cellular stress at the ER activates other two forms of autophagy (microautophagy or CMA) as an efficient cellular compensatory process to reduce cellular stress and improve cell survival. CMA requires a specific cytosolic protein containing a KFERQ-like pentapeptide sequence that is recognized by HSC70 and subsequently translocated into the lysosomal lumen via interaction with LAMP2A for degradation. Microautophagy involves direct incorporation of cytoplasmic materials into endosomes or lysosomes for either degradation or export outside to reduce cellular stress. Microautophagy is also involved in the exosome secretion of cytoplasmic cargo to reduce cellular stress.