title: Positive regulation of apoptosis signal-regulating kinase 1 by hD53L1.
abstract: Apoptosis signal-regulating kinase 1 (ASK1) is a mitogen-activated protein kinase kinase kinase family member that plays a central role in cytokine- and stress-induced apoptosis by activating c-Jun N-terminal kinase and p38 signaling cascades. ASK1-induced apoptotic activity is up-regulated by two cellular factors, Daxx and TRAF2, through direct protein-protein interactions. Daxx and TRAF2 are death receptor-associated proteins in Fas and tumor necrosis factor-alpha pathways, respectively. Recent studies suggest that calcium signaling may regulate ASK1 pathway. Here we report that human D53L1, a member of the tumor protein D52 family involved in cell proliferation and calcium signaling, up-regulates the ASK1-induced apoptosis. The human D53L1 physically interacts with the C-terminal regulatory domain of ASK1 and promotes ASK1-induced apoptotic activity by activating caspase signaling in mammalian cells. In luciferase reporter assays, hD53L1 activates c-Jun N-terminal kinase-mediated transactivation in the presence of ASK1. Expression of hD53L1 enhances autophosphorylation and kinase activity of ASK1 but has no effect on ASK1 oligomerization that is necessary for kinase activity and on binding of ASK1 to MKK6, a downstream factor of ASK1. Taken together, these results suggest that activation of ASK1 by hD53L1 may provide a novel mechanism for ASK1 regulation.
authors.affiliation: Research Center for Systemic Proteomics, Korea Research Institute of Bioscience and Biotechnology, P.O. Box 115, Yusong, Taejon 305-600, South Korea. scho@kribb.re.kr
authors.forename: Sayeon
authors.initials: S
authors.lastname: Cho
authors.forename: Hyung-Mun
authors.initials: HM
authors.lastname: Ko
authors.forename: Jeong-Min
authors.initials: JM
authors.lastname: Kim
authors.forename: Jung-A
authors.initials: JA
authors.lastname: Lee
authors.forename: Jae-Eun
authors.initials: JE
authors.lastname: Park
authors.forename: Mi-Sun
authors.initials: MS
authors.lastname: Jang
authors.forename: Sung Goo
authors.initials: SG
authors.lastname: Park
authors.forename: Do Hee
authors.initials: DH
authors.lastname: Lee
authors.forename: Seong-Eon
authors.initials: SE
authors.lastname: Ryu
authors.forename: Byoung-Chul
authors.initials: BC
authors.lastname: Park
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D017209:Apoptosis / Q000502:physiology; D002352:Carrier Proteins / Q000378:metabolism*; D002460:Cell Line; D056970:Co-Repressor Proteins; D004789:Enzyme Activation; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D048848:MAP Kinase Kinase Kinase 5; D020930:MAP Kinase Kinase Kinases / Q000378:metabolism*; D018832:Molecular Chaperones; D009363:Neoplasm Proteins / Q000378:metabolism*; D009687:Nuclear Proteins / Q000378:metabolism; D010766:Phosphorylation; D011485:Protein Binding; D011506:Proteins / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology*; D047992:TNF Receptor-Associated Factor 2
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; D056970:Co-Repressor Proteins; C106985:DAXX protein, human; D047908:Intracellular Signaling Peptides and Proteins; D018832:Molecular Chaperones; D009363:Neoplasm Proteins; D009687:Nuclear Proteins; D011506:Proteins; D047992:TNF Receptor-Associated Factor 2; C114751:TPD52 protein, human; D048848:MAP Kinase Kinase Kinase 5; D020930:MAP Kinase Kinase Kinases; C482858:MAP3K5 protein, human