title: Architecture and dynamics of the autophagic phosphatidylinositol 3-kinase complex.
abstract: The class III phosphatidylinositol 3-kinase complex I (PI3KC3-C1) that functions in early autophagy consists of the lipid kinase VPS34, the scaffolding protein VPS15, the tumor suppressor BECN1, and the autophagy-specific subunit ATG14. The structure of the ATG14-containing PI3KC3-C1 was determined by single-particle EM, revealing a V-shaped architecture. All of the ordered domains of VPS34, VPS15, and BECN1 were mapped by MBP tagging. The dynamics of the complex were defined using hydrogen-deuterium exchange, revealing a novel 20-residue ordered region C-terminal to the VPS34 C2 domain. VPS15 organizes the complex and serves as a bridge between VPS34 and the ATG14:BECN1 subcomplex. Dynamic transitions occur in which the lipid kinase domain is ejected from the complex and VPS15 pivots at the base of the V. The N-terminus of BECN1, the target for signaling inputs, resides near the pivot point. These observations provide a framework for understanding the allosteric regulation of lipid kinase activity.
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States.
authors.forename: Sulochanadevi
authors.initials: S
authors.lastname: Baskaran
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States.
authors.forename: Lars-Anders
authors.initials: LA
authors.lastname: Carlson
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States.
authors.forename: Goran
authors.initials: G
authors.lastname: Stjepanovic
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States.
authors.forename: Lindsey N
authors.initials: LN
authors.lastname: Young
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States.
authors.forename: Do Jin
authors.initials: DJ
authors.lastname: Kim
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States.
authors.forename: Patricia
authors.initials: P
authors.lastname: Grob
authors.affiliation: Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, United States.
authors.forename: Robin E
authors.initials: RE
authors.lastname: Stanley
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States.
authors.forename: Eva
authors.initials: E
authors.lastname: Nogales
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States.
authors.forename: James H
authors.initials: JH
authors.lastname: Hurley
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001343:Autophagy; D058546:Class III Phosphatidylinositol 3-Kinases / Q000737:chemistry / Q000378:metabolism* / Q000648:ultrastructure; D006801:Humans; D008854:Microscopy, Electron; D008969:Molecular Sequence Data; D011487:Protein Conformation; D017386:Sequence Homology, Amino Acid
chemical_list: D058546:Class III Phosphatidylinositol 3-Kinases
keywords: autophagy; biophysics; human; hydrogen–deuterium exchange; lipid kinase; protein kinase; structural biology; three dimensional electron microscopy