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Updated: Jun 25, 2026

Study of Protein-protein Interactions in Autophagy Research
Published on: September 9, 2017
Two Beclin 1-binding proteins, Atg14L and Rubicon, reciprocally regulate autophagy at different stages
Kohichi Matsunaga1, Tatsuya Saitoh, Keisuke Tabata
1Department of Cellular Regulation, Research Institute for Microbial Diseases, Osaka University, Suita, Japan.
Abstract:
Beclin 1, a protein essential for autophagy, binds to hVps34/Class III phosphatidylinositol-3-kinase and UVRAG. Here, we have identified two Beclin 1 associated proteins, Atg14L and Rubicon. Atg14L and UVRAG bind to Beclin 1 in a mutually exclusive manner, whereas Rubicon binds only to a subpopulation of UVRAG complexes; thus, three different Beclin 1 complexes exist. GFP-Atg14L localized to the isolation membrane and autophagosome, as well as to the ER and unknown puncta. Knockout of Atg14L in mouse ES cells caused a defect in autophagosome formation. GFP-Rubicon was localized at the endosome/lysosome. Knockdown of Rubicon caused enhancement of autophagy, especially at the maturation step, as well as enhancement of endocytic trafficking. These data suggest that the Beclin 1-hVps34 complex functions in two different steps of autophagy by altering the subunit composition.
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