title: Structural model of the TRPP2/PKD1 C-terminal coiled-coil complex produced by a combined computational and experimental approach.
abstract: Autosomal dominant polycystic kidney disease (ADPKD) is caused by mutations in TRPP2 and PKD1, which form an ion channel/receptor complex containing three TRPP2 and one PKD1. A TRPP2 C-terminal coiled-coil trimer, critical for the assembly of this complex, associates with a single PKD1 C-terminal coiled-coil. Many ADPKD pathogenic mutations result in the abolishment of the TRPP2/PKD1 coiled-coil complex. To gain molecular and functional insights into this heterotetrameric complex, we computationally constructed a structural model by using a two-step docking strategy, based on a known crystal structure of the TRPP2 coiled-coil trimer. The model shows that this tetrameric complex has a novel di-trimer configuration: An upstream trimer made of three TRPP2 helices and a downstream trimer made of two TRPP2 helices and one PKD1 helix. Mutagenesis and biochemical analysis identified critical TRPP2/PKD1 interface contacts essential for the heteromeric coiled-coil complex. Mutation of these interface positions in the full-length proteins showed that these interactions were critical for the assembly of the full-length complex in cells. Our results provide a means to specifically weaken the TRPP2 and PKD1 association, thus facilitating future in vitro and in vivo studies on the functional importance of this association.
authors.affiliation: Department of Biochemistry and Molecular Biophysics, Howard Hughes Medical Institute and Center for Computational Biology and Bioinformatics, Columbia University, New York, NY 10032, USA.
authors.forename: Jiang
authors.initials: J
authors.lastname: Zhu
authors.forename: Yong
authors.initials: Y
authors.lastname: Yu
authors.forename: Maximilian H
authors.initials: MH
authors.lastname: Ulbrich
authors.forename: Ming-hui
authors.initials: MH
authors.lastname: Li
authors.forename: Ehud Y
authors.initials: EY
authors.lastname: Isacoff
authors.forename: Barry
authors.initials: B
authors.lastname: Honig
authors.forename: Jian
authors.initials: J
authors.lastname: Yang
mesh_terms: D000818:Animals; D004220:Disulfides / Q000737:chemistry; D057809:HEK293 Cells; D006801:Humans; D051379:Mice; D008958:Models, Molecular; D056004:Molecular Dynamics Simulation; D008969:Molecular Sequence Data; D009154:Mutation; D016891:Polycystic Kidney, Autosomal Dominant / Q000235:genetics* / Q000503:physiopathology; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D050396:TRPP Cation Channels / Q000737:chemistry* / Q000235:genetics
chemical_list: D004220:Disulfides; D050396:TRPP Cation Channels