Article

Human WIPI-1 puncta-formation: a novel assay to assess mammalian autophagy.

Autophagy Laboratory, Department of Molecular Biology, University of Tuebingen, Auf der Morgenstelle 15, 72076 Tuebingen, Germany.
FEBS Letters (Impact Factor: 3.34). 08/2007; 581(18):3396-404. DOI: 10.1016/j.febslet.2007.06.040
Source: PubMed

ABSTRACT Autophagy depends on the activity of phosphoinositide-3 kinase class III to generate PI(3)P. We identified the human WIPI protein family of PI(3)P-binding factors and showed that WIPI-1 (Atg18) is linked to autophagy in human cells. Induction of autophagy by rapamycin, gleevec, thapsigargin and amino acid deprivation led to an accumulation of WIPI-1 at LC3-positive membrane structures (WIPI-1 puncta-formation), suggested to represent autophagosomal isolation membranes. WIPI-1 puncta-formation is inhibited by wortmannin and LY294002, and PI(3)P-binding-deficient WIPI-1 is puncta-formation-incompetent. Quantification of WIPI-1 puncta should be suitable to assay mammalian autophagy.

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