Atg14 : A Key Player in Orchestrating Autophagy

Abstract EN

Phosphorylation of phosphatidylinositol (PtdIns) by a PtdIns 3-kinase is an essential process in autophagy.

Atg14, a specific subunit of one of the PtdIns 3-kinase complexes, targets the complex to the probable site of autophagosome formation, thereby, sorting the complex to function specifically in autophagy.

The N-terminal half of Atg14, containing coiled-coil domains, is required to form the PtdIns 3-kinase complex and target it to the proper site.

The C-terminal half of yeast Atg14 is suggested to be involved in the formation of a normal-sized autophagosome.

The C-terminal half of mammalian Atg14 contains the Barkor/Atg14(L) autophagosome-targeting sequence (BATS) domain that preferentially binds to the highly curved membranes containing PtdIns(3)P and is proposed to target the PtdIns 3-kinase complex efficiently to the isolation membrane.

Thus, the N- and C-terminal halves of Atg14 are likely to have an essential core function and a regulatory role, respectively.