title: The Molecular Basis of Aichi Virus 3A Protein Activation of Phosphatidylinositol 4 Kinase IIIβ, PI4KB, through ACBD3.
abstract: Phosphatidylinositol 4-kinase III beta (PI4KIIIβ) is an essential enzyme in mediating membrane transport, and plays key roles in facilitating viral infection. Many pathogenic positive-sense single-stranded RNA viruses activate PI4KIIIβ to generate phosphatidylinositol 4-phosphate (PI4P)-enriched organelles for viral replication. The molecular basis for PI4KIIIβ activation during viral infection has remained largely unclear. We describe the biochemical reconstitution and characterization of the complex of PI4KIIIβ with the Golgi protein Acyl-coenzyme A binding domain containing protein 3 (ACBD3) and Aichi virus 3A protein on membranes. We find that 3A directly activates PI4KIIIβ, and this activation is sensitized by ACBD3. The interfaces between PI4KIIIβ-ACBD3 and ACBD3-3A were mapped with hydrogen-deuterium exchange mass spectrometry (HDX-MS). Determination of the crystal structure of the ACBD3 GOLD domain revealed a unique N terminus that mediates the interaction with 3A. Rationally designed complex-disrupting mutations in both ACBD3 and PI4KIIIβ completely abrogated the sensitization of 3A activation by ACBD3.
authors.affiliation: Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8P 5C2, Canada.
authors.forename: Jacob A
authors.initials: JA
authors.lastname: McPhail
authors.affiliation: Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8P 5C2, Canada.
authors.forename: Erik H
authors.initials: EH
authors.lastname: Ottosen
authors.affiliation: Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8P 5C2, Canada.
authors.forename: Meredith L
authors.initials: ML
authors.lastname: Jenkins
authors.affiliation: Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8P 5C2, Canada. Electronic address: jeburke@uvic.ca.
authors.forename: John E
authors.initials: JE
authors.lastname: Burke
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000737:chemistry / Q000378:metabolism*; D001665:Binding Sites; D002462:Cell Membrane / Q000378:metabolism; D018360:Crystallography, X-Ray; D041961:Deuterium Exchange Measurement; D004789:Enzyme Activation; D006801:Humans; D052699:Kobuvirus / Q000737:chemistry / Q000378:metabolism*; D013058:Mass Spectrometry; D008565:Membrane Proteins / Q000737:chemistry / Q000378:metabolism*; D008958:Models, Molecular; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D011487:Protein Conformation; D014764:Viral Proteins / Q000737:chemistry* / Q000378:metabolism*; D014779:Virus Replication
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D008565:Membrane Proteins; D017853:Phosphotransferases (Alcohol Group Acceptor); D014764:Viral Proteins; C449459:ACBD3 protein, human; C581087:PI4KB protein, human
keywords: ACBD3; HDX-MS; PI4K; PI4KB; X-ray crystallography; hydrogen-deuterium exchange mass spectrometry; lipid signaling; phosphatidylinositol 4 kinase; phosphoinositide; picornaviruses