Chaperone-mediated autophagy

Chaperone-mediated autophagy (pronunciation: chap-er-one me-dee-ay-ted aw-to-fa-gee) is a selective form of autophagy that involves the direct translocation of cytosolic proteins across the lysosomal membrane for degradation.

Etymology

The term "chaperone-mediated autophagy" is derived from the role of chaperone proteins in this process. The word "chaperone" comes from the French "chaperon," meaning a protective guide, which is a fitting description for the role these proteins play. "Autophagy" is derived from the Greek words "auto" (self) and "phagein" (to eat), reflecting the process's role in cellular self-degradation.

Process

Chaperone-mediated autophagy begins with the recognition of the target protein by the chaperone protein Hsc70. This complex then binds to the lysosomal receptor protein LAMP2A, which facilitates the unfolding and translocation of the target protein into the lysosome. Inside the lysosome, the protein is degraded by lysosomal hydrolases.

Related Terms

Autophagy: A cellular process of self-degradation, where the cell recycles its own components to provide the necessary building blocks for maintaining cellular functions and adapting to changing conditions.
Macroautophagy: A type of autophagy where cellular components are sequestered into a double-membrane structure called an autophagosome, which then fuses with a lysosome for degradation.
Microautophagy: A type of autophagy where cytosolic components are directly engulfed by the lysosomal membrane for degradation.
Hsc70: A chaperone protein that recognizes and binds to the target protein in chaperone-mediated autophagy.
LAMP2A: A lysosomal receptor protein that facilitates the translocation of the target protein into the lysosome in chaperone-mediated autophagy.
Lysosomal hydrolases: Enzymes inside the lysosome that degrade the target protein in chaperone-mediated autophagy.