Repair or Lysophagy: Dealing with Damaged Lysosomes

Area of Science:

• Cell Biology
• Molecular Biology
• Disease Pathogenesis

Background:

• Lysosomal damage is a critical stress in diseases like cancer and neurodegeneration.
• The endosomal sorting complex required for transport (ESCRT) machinery can repair minor lysosomal damage.
• Failure to repair leads to lysophagy, a selective form of autophagy for lysosome clearance.

Purpose of the Study:

• To review cellular mechanisms governing lysosome repair versus lysophagy.
• To highlight the role of damage-induced glycan exposure in triggering lysophagy.
• To discuss regulatory factors in lysosome homeostasis.

Main Methods:

• Literature review of recent data on cellular damage sensing.
• Analysis of ubiquitination and autophagy pathways.
• Examination of regulatory proteins like VCP/p97.

Main Results:

• Exposure of lysosomal luminal glycans to the cytosol is a key trigger for ubiquitination.
• Ubiquitination tags damaged lysosomes for clearance via lysophagy.
• The AAA-ATPase VCP/p97 processes ubiquitinated proteins, influencing lysophagy.

Conclusions:

• Cellular decision between lysosome repair and lysophagy is tightly regulated.
• Ubiquitination and autophagy pathways are central to lysosome quality control.
• Understanding these mechanisms offers insights into degenerative diseases and cancer therapy.