title: Sequential Engagement of Distinct MLKL Phosphatidylinositol-Binding Sites Executes Necroptosis.
abstract: Necroptosis is a cell death pathway regulated by the receptor interacting protein kinase 3 (RIPK3) and the mixed lineage kinase domain-like (MLKL) pseudokinase. How MLKL executes plasma membrane rupture upon phosphorylation by RIPK3 remains controversial. Here, we characterize the hierarchical transduction of structural changes in MLKL that culminate in necroptosis. The MLKL brace, proximal to the N-terminal helix bundle (NB), is involved in oligomerization to facilitate plasma membrane targeting through the low-affinity binding of NB to phosphorylated inositol polar head groups of phosphatidylinositol phosphate (PIP) phospholipids. At the membrane, the NB undergoes a "rolling over" mechanism to expose additional higher-affinity PIP-binding sites responsible for robust association to the membrane and displacement of the brace from the NB. PI(4,5)P2 is the preferred PIP-binding partner. We investigate the specific association of MLKL with PIPs and subsequent structural changes during necroptosis.
authors: Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA.
authors: Giovanni
authors: G
authors: Quarato
authors: Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA.
authors: Cliff S
authors: CS
authors: Guy
authors: Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA.
authors: Christy R
authors: CR
authors: Grace
authors: Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA.
authors: Fabien
authors: F
authors: Llambi
authors: Molecular Interaction Analysis Shared Resource, St. Jude Children's Research Hospital, Memphis, TN 38105, USA.
authors: Amanda
authors: A
authors: Nourse
authors: Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA.
authors: Diego A
authors: DA
authors: Rodriguez
authors: Cell and Tissue Imaging Center, St. Jude Children's Research Hospital, Memphis, TN 38105, USA.
authors: Randall
authors: R
authors: Wakefield
authors: Cell and Tissue Imaging Center, St. Jude Children's Research Hospital, Memphis, TN 38105, USA.
authors: Sharon
authors: S
authors: Frase
authors: Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA; Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, TN 38105, USA. Electronic address: tudor.moldoveanu@stjude.org.
authors: Tudor
authors: T
authors: Moldoveanu
authors: Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA. Electronic address: douglas.green@stjude.org.
authors: Douglas R
authors: DR
authors: Green
mesh_terms: D000818:Animals; D017209:Apoptosis; D001665:Binding Sites; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D005347:Fibroblasts / Q000166:cytology* / Q000378:metabolism; D006801:Humans; D051379:Mice; D008958:Models, Molecular; D018129:Phosphatidylinositol Phosphates / Q000378:metabolism*; D010766:Phosphorylation; D011494:Protein Kinases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D055503:Protein Multimerization; D017434:Protein Structure, Tertiary; D053422:Receptor-Interacting Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*
chemical_list: D018129:Phosphatidylinositol Phosphates; C570694:MLKL protein, mouse; D011494:Protein Kinases; C119705:RIPK3 protein, human; D053422:Receptor-Interacting Protein Serine-Threonine Kinases