Related Experiment Video
Updated: Jun 2, 2026

Study of Protein-protein Interactions in Autophagy Research
Published on: September 9, 2017
PtdIns 3-Kinase Orchestrates Autophagosome Formation in Yeast
Keisuke Obara1, Yoshinori Ohsumi
1Faculty of Pharmaceutical Sciences, Hokkaido University, Kita-12 jo Nishi-6 chome, Kitaku, Sapporo 060-0812, Japan.
Abstract:
Eukaryotic cells can massively transport their own cytoplasmic contents into a lytic compartment, the vacuole/lysosome, for recycling through a conserved system called autophagy. The key process in autophagy is the sequestration of cytoplasmic contents within a double-membrane structure, the autophagosome. Autophagosome formation requires the elaborate cooperation of Atg (autophagy-related) proteins and lipid molecules. Phosphorylation of phosphatidylinositol (PtdIns) by a PtdIns 3-kinase, Vps34, is a key step in coordinating Atg proteins and lipid molecules. Vps34 forms two distinct protein complexes, only one of which is involved in generating autophagic membranes. Upon induction of autophagy, PtdIns(3)P, the enzymatic product of PtdIns 3-kinase, is massively transported into the lumen of the vacuole via autophagy. PtdIns(3)P is enriched on the inner membrane of the autophagosome. PtdIns(3)P recruits the Atg18-Atg2 complex and presumably other Atg proteins to autophagic membranes, thereby coordinating lipid molecules and Atg proteins.
Related Concept Videos
PI3K/mTOR/AKT Signaling Pathway
Tail-anchoring of Proteins in the ER Membrane
mTOR Signaling and Cancer Progression
The mTOR pathway or the...
MAPK Signaling Cascades
Phosphoinositides and PIPs
Different phosphoinositides are synthesized and recruited on the cytosolic face of the plasma membrane. The localization of specific phosphoinositides concentrated in separate membrane...
Autophagy
An autophagic pathway consists of a series of signaling events activated in response to diverse stress and physiological conditions such as food deprivation,...

