Data from: Phagolysosomes break down the membrane of a non-apoptotic corpse independent of macroautophagy

Cell corpses must be cleared in an efficient manner to maintain tissue
homeostasis and regulate immune responses. Ubiquitin-like Atg8/LC3 family
proteins promote the degradation of membranes and internal cargo during
both macroautophagy and corpse clearance, raising the question how
macroautophagy contributes to corpse clearance. Studying the clearance of
non-apoptotic dying polar bodies in Caenorhabditis elegans embryos, we
show that the LC3 ortholog LGG-2 is enriched inside the polar body
phagolysosome independent of autophagosome formation. We
demonstrate that ATG-16.1 and ATG-16.2, which promote membrane association
of lipidated Atg8/LC3 proteins, redundantly promote polar body membrane
breakdown in phagolysosomes independent of their role in macroautophagy.
We also show that the lipid scramblase ATG-9 is needed for autophagosome
formation in early embryos but is dispensable for timely polar body
membrane breakdown or protein cargo degradation. These findings
demonstrate that macroautophagy is not required to promote polar body
degradation, in contrast to recent findings with apoptotic corpse
clearance in C. elegans embryos. Determining how factors
regulating Atg8/LC3 promote the breakdown of different types of
cell corpses in distinct cell types or metabolic states is likely to give
insights into the mechanisms of immunoregulation during normal
development, physiology, and disease.