Apoptosis is a program of cellular suicide initiated by a wide range of physiological stimuli. Acting in a cellautonomous manner the apoptotic process eliminates superfluous or harmful cells without damaging neighboring cells. The signaling events which regulate the decision to die are only beginning to be understood. The goal of this proposal is to elucidate a signaling pathway responsive to the Drosophila Reaper protein a central regulator of apoptosis. We and others have shown that appropriate extracts prepared from Xenopus eggs faithfully recapitulate both biochemical and morphological events of apoptosis in vitro. Using this system we discovered that Drosophila Reaper protein can induce apoptosis in a vertebrate context (subsequently confirmed using mammalian cells). However it remains unclear whether vertebrate cells contain Reaperlike protein or perhaps activate this pathway through other means. Reaper triggers release of cytochrome c from the mitochondria to the cytosol promoting activation of caspases and ensuing cell death. We identified a novel Reaperbinding protein Scythe which is essential for Reaper action.
The Specific Aims of this proposal focus on elucidating the molecular mechanism whereby Reaper/Scythe triggers cytochrome c release and on the identification of vertebrate regulators of Scythe.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM061919-02
Application #
6387256
Study Section
Cell Development and Function Integrated Review Group (CDF)
Program Officer
Zatz, Marion M
Project Start
2000-08-01
Project End
2004-07-31
Budget Start
2001-08-01
Budget End
2002-07-31
Support Year
2
Fiscal Year
2001
Total Cost
$215,600
Indirect Cost
Name
Duke University
Department
Pharmacology
Type
Schools of Medicine
DUNS #
071723621
City
Durham
State
NC
Country
United States
Zip Code
27705
Kurokawa, Manabu; Kornbluth, Sally (2009) Caspases and kinases in a death grip. Cell 138:838-54
Freel, Christopher D; Richardson, D Ashley; Thomenius, Michael J et al. (2008) Mitochondrial localization of Reaper to promote inhibitors of apoptosis protein degradation conferred by GH3 domain-lipid interactions. J Biol Chem 283:367-79
Sasaki, Toru; Gan, Eugene C; Wakeham, Andrew et al. (2007) HLA-B-associated transcript 3 (Bat3)/Scythe is essential for p300-mediated acetylation of p53. Genes Dev 21:848-61
Colon-Ramos, Daniel A; Shenvi, Christina L; Weitzel, Douglas H et al. (2006) Direct ribosomal binding by a cellular inhibitor of translation. Nat Struct Mol Biol 13:103-11
Kornbluth, Sally; White, Kristin (2005) Apoptosis in Drosophila: neither fish nor fowl (nor man, nor worm). J Cell Sci 118:1779-87
Olson, Michael R; Holley, Christopher L; Yoo, Soon Ji et al. (2003) Reaper is regulated by IAP-mediated ubiquitination. J Biol Chem 278:4028-34
Olson, Michael R; Holley, Christopher L; Gan, Eugene C et al. (2003) A GH3-like domain in reaper is required for mitochondrial localization and induction of IAP degradation. J Biol Chem 278:44758-68
Colon-Ramos, Daniel A; Irusta, Pablo M; Gan, Eugene C et al. (2003) Inhibition of translation and induction of apoptosis by Bunyaviral nonstructural proteins bearing sequence similarity to reaper. Mol Biol Cell 14:4162-72
Tashker, Jessica S; Olson, Michael; Kornbluth, Sally (2002) Post-cytochrome C protection from apoptosis conferred by a MAPK pathway in Xenopus egg extracts. Mol Biol Cell 13:393-401
Holley, Christopher L; Olson, Michael R; Colon-Ramos, Daniel A et al. (2002) Reaper eliminates IAP proteins through stimulated IAP degradation and generalized translational inhibition. Nat Cell Biol 4:439-44

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