title: Evolutionary divergence of the necroptosis effector MLKL.
abstract: The pseudokinase, MLKL (mixed-lineage kinase domain-like), is the most terminal obligatory component of the necroptosis cell death pathway known. Phosphorylation of the MLKL pseudokinase domain by the protein kinase, receptor interacting protein kinase-3 (RIPK3), is known to be the key step in MLKL activation. This phosphorylation event is believed to trigger a molecular switch, leading to exposure of the N-terminal four-helix bundle (4HB) domain of MLKL, its oligomerization, membrane translocation and ultimately cell death. To examine how well this process is evolutionarily conserved, we analysed the function of MLKL orthologues. Surprisingly, and unlike their mouse, horse and frog counterparts, human, chicken and stickleback 4HB domains were unable to induce cell death when expressed in murine fibroblasts. Forced dimerization of the human MLKL 4HB domain overcame this defect and triggered cell death in human and mouse cell lines. Furthermore, recombinant proteins from mouse, frog, human and chicken MLKL, all of which contained a 4HB domain, permeabilized liposomes, and were most effective on those designed to mimic plasma membrane composition. These studies demonstrate that the membrane-permeabilization function of the 4HB domain is evolutionarily conserved, but reveal that execution of necroptotic death by it relies on additional factors that are poorly conserved even among closely related species.
authors: Cell Signalling and Cell Death Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia.|Department of Medical Biology, University of Melbourne, Parkville, Victoria 3050, Australia.
authors: M C
authors: MC
authors: Tanzer
authors: Cell Signalling and Cell Death Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia.|Department of Medical Biology, University of Melbourne, Parkville, Victoria 3050, Australia.
authors: I
authors: I
authors: Matti
authors: Cell Signalling and Cell Death Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia.|Department of Medical Biology, University of Melbourne, Parkville, Victoria 3050, Australia.
authors: J M
authors: JM
authors: Hildebrand
authors: Cell Signalling and Cell Death Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia.
authors: S N
authors: SN
authors: Young
authors: Cell Signalling and Cell Death Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia.
authors: A
authors: A
authors: Wardak
authors: Cell Signalling and Cell Death Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia.|Department of Medical Biology, University of Melbourne, Parkville, Victoria 3050, Australia.
authors: A
authors: A
authors: Tripaydonis
authors: Cell Signalling and Cell Death Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia.|Department of Medical Biology, University of Melbourne, Parkville, Victoria 3050, Australia.
authors: E J
authors: EJ
authors: Petrie
authors: Cell Signalling and Cell Death Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia.|Department of Medical Biology, University of Melbourne, Parkville, Victoria 3050, Australia.
authors: A L
authors: AL
authors: Mildenhall
authors: Cell Signalling and Cell Death Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia.|Department of Medical Biology, University of Melbourne, Parkville, Victoria 3050, Australia.
authors: D L
authors: DL
authors: Vaux
authors: Cell Signalling and Cell Death Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia.|Department of Medical Biology, University of Melbourne, Parkville, Victoria 3050, Australia.
authors: J E
authors: JE
authors: Vince
authors: Cell Signalling and Cell Death Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia.|Department of Medical Biology, University of Melbourne, Parkville, Victoria 3050, Australia.
authors: P E
authors: PE
authors: Czabotar
authors: Cell Signalling and Cell Death Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia.|Department of Medical Biology, University of Melbourne, Parkville, Victoria 3050, Australia.
authors: J
authors: J
authors: Silke
authors: Cell Signalling and Cell Death Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia.|Department of Medical Biology, University of Melbourne, Parkville, Victoria 3050, Australia.
authors: J M
authors: JM
authors: Murphy
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002460:Cell Line; D002463:Cell Membrane Permeability / Q000187:drug effects; D002645:Chickens; D019143:Evolution, Molecular; D019073:HT29 Cells; D006367:HeLa Cells; D006736:Horses; D006801:Humans; D008081:Liposomes / Q000378:metabolism; D051379:Mice; D009336:Necrosis / Q000235:genetics; D010766:Phosphorylation / Q000187:drug effects; D000072417:Protein Domains; D011494:Protein Kinases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D053422:Receptor-Interacting Protein Serine-Threonine Kinases / Q000378:metabolism; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000494:pharmacology
chemical_list: D008081:Liposomes; D011994:Recombinant Proteins; C570693:MLKL protein, human; D011494:Protein Kinases; C119705:RIPK3 protein, human; D053422:Receptor-Interacting Protein Serine-Threonine Kinases