The BARA necessities of PtdIns 3-kinase activation in autophagy

Novel PtdIns(3)P-binding protein Etf1 functions as an effector of the Vps34 PtdIns 3-kinase in autophagy

Autophagy is the process whereby cytoplasmic cargo (e.g., protein and organelles) are sequestered within a double membrane-enclosed transport vesicle and degraded after vesicle fusion with the vacuole/lysosome. Current evidence suggests that the Vps34 phosphatidylinositol 3-kinase is essential for macroautophagy, a starvation-induced autophagy pathway (Kihara et al., 2001). Here, we characteriz...

1 Dynamics and function of PtdIns ( 3 ) P in autophagy

Dynamics and function of PtdIns(3)P in autophagy.

Phosphorylation of phosphatidylinositol (PtdIns) by PtdIns 3-kinase is essential for autophagy. However, the distribution and function of the enzymatic product, PtdIns 3-phosphate (PtdIns(3)P), has been unknown. We monitored PtdIns(3)P distribution during autophagy by live imaging, biochemistry, and electron microscopy, and found that PtdIns(3)P is massively delivered into the vacuole via autop...

PtdIns(3,4,5)P3-Dependent Activation of the mTORC2 Kinase Complex.

UNLABELLED mTOR serves as a central regulator of cell growth and metabolism by forming two distinct complexes, mTORC1 and mTORC2. Although mechanisms of mTORC1 activation by growth factors and amino acids have been extensively studied, the upstream regulatory mechanisms leading to mTORC2 activation remain largely elusive. Here, we report that the pleckstrin homology (PH) domain of SIN1, an esse...

PtdIns 3-Kinase Orchestrates Autophagosome Formation in Yeast

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) pro...