title: Tumor necrosis factor receptor 1 is an ATPase regulated by silencer of death domain.
abstract: Self-aggregation of tumor necrosis factor receptor type 1 (TNFR1) induces spontaneous downstream signaling and results in cell death. It has been suggested that silencer of death domain (SODD) binds TNFR1 monomers to prevent self-aggregation. We found that SODD binds through its BAG domain to the ATPase domain of Hsp70. We also determined that SODD binds through its BAG domain to TNFR1. ATP, but not nonhydrolyzable ATP-gamma S, regulates the SODD binding by Hsp70 or TNFR1. ATP binding by TNFR1 was abolished when a point mutation was introduced into a phosphate-binding loop motif characteristic of ATP-binding proteins, suggesting that TNFR1 functions as an ATPase. Furthermore, TNFR1 was present in aggregates in ATP-depleted cells and SODD disassembled aggregates in vitro only in the presence of ATP. These data suggest that SODD functions as a cofactor analogous to the nucleotide exchange factor BAG-1, which modulates the ATPase cycle of Hsp70 proteins. We propose a new model in which a nucleotide-dependent conformational change in TNFR1 has a key role in regulating TNF signaling.
authors.affiliation: Gamete Biology Section, Laboratory of Reproductive and Developmental Toxicology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina 27709, USA.
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Miki
authors.forename: Edward M
authors.initials: EM
authors.lastname: Eddy
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D015703:Antigens, CD / Q000235:genetics / Q000378:metabolism*; D017209:Apoptosis; D001665:Binding Sites / Q000235:genetics; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D050883:HSC70 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D066298:In Vitro Techniques; D051379:Mice; D008954:Models, Biological; D008969:Molecular Sequence Data; D017434:Protein Structure, Tertiary; D011956:Receptors, Cell Surface / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D018124:Receptors, Tumor Necrosis Factor / Q000235:genetics / Q000378:metabolism*; D047888:Receptors, Tumor Necrosis Factor, Type I; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D015703:Antigens, CD; C116906:BAG4 protein, human; C487979:Bag4 protein, mouse; D002352:Carrier Proteins; D050883:HSC70 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins; C494371:HSPA8 protein, human; C494372:Hspa8 protein, mouse; D011956:Receptors, Cell Surface; D018124:Receptors, Tumor Necrosis Factor; D047888:Receptors, Tumor Necrosis Factor, Type I; D011993:Recombinant Fusion Proteins; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases