Phosphatidylinositol-3-phosphate Clearance Plays a Key Role in Autophagosome Completion
Overview
Authors
Affiliations
Background: The biogenesis of autophagosomes, the hallmark of autophagy, depends on the function of the autophagy-related (Atg) proteins and the generation of phosphatidylinositol-3-phosphate (PtdIns3P) at the phagophore assembly site (PAS), the location where autophagosomes arise. The current model is that PtdIns3P is involved primarily in the recruitment of Atg proteins to the PAS and that once an autophagosome is complete, the Atg machinery is released from its surface back into the cytoplasm and reused for the formation of new vesicles.
Results: We have identified a PtdIns3P phosphatase, Ymr1, that is essential for the normal progression of both bulk and selective types of autophagy. This protein is recruited to the PAS at an early stage of formation of this structure through a process that requires both its GRAM domain and its catalytic activity. In the absence of Ymr1, Atg proteins fail to dissociate from the limiting membrane of autophagosomes, and these vesicles accumulate in the cytoplasm.
Conclusions: Our data thus reveal a key role for PtdIns3P turnover in the regulation of the late steps of autophagosome biogenesis and indicate that the disassembly of the Atg machinery from the surface of autophagosomes is a requisite for their fusion with the vacuole.
Autophagosomes coated in situ with nanodots act as personalized cancer vaccines.
Huang W, You W, Zhu Y, Gao F, Wu Z, Chen G Nat Nanotechnol. 2025; .
PMID: 39753731 DOI: 10.1038/s41565-024-01826-8.
Temporal dissection of the roles of Atg4 and ESCRT in autophagosome formation in yeast.
Li H, Song J, He C, Xie M, Zhang Z, Zhou Y Cell Death Differ. 2024; .
PMID: 39715823 DOI: 10.1038/s41418-024-01438-8.
Lipids associated with autophagy: mechanisms and therapeutic targets.
Jarocki M, Turek K, Saczko J, Tarek M, Kulbacka J Cell Death Discov. 2024; 10(1):460.
PMID: 39477959 PMC: 11525783. DOI: 10.1038/s41420-024-02224-8.
Liu J, Ma H, Wu Z, Ji Y, Liang Y Int J Mol Sci. 2024; 25(20).
PMID: 39456939 PMC: 11508585. DOI: 10.3390/ijms252011160.
The multifaceted roles of selective autophagy receptors in viral infections.
Luo R, Wang T, Lan J, Lu Z, Chen S, Sun Y J Virol. 2024; 98(10):e0081424.
PMID: 39212450 PMC: 11494948. DOI: 10.1128/jvi.00814-24.