Apoptosis is the genetically controlled death of unwanted or damaged cells during development and homeostasis. In recent years, a combination of genetic and biochemical approaches have been used to identify several families of molecules which act to facilitate or prevent apoptosis. Despite these advances in our knowledge of the basic machinery of apoptosis, we still know relatively little about how this process is regulated and executed during normal development. The long term goal of our research is to investigate developmental apoptosis using the powerful genetic and molecular techniques available in Drosophila. These studies will provide a foundation for understanding how apoptosis is misregulated in diseases such as neurodegeneration and cancer. The reaper (rpr), grim and hid genes act as central initiators of apoptosis in the Drosophila embryo. In the absence of all three genes embryonic apoptosis is blocked. Each of these genes induces caspase-dependent apoptosis when ectopically expressed. Current models for rpr and hid activity predict that apoptosis is initiated by physical interactions between Rpr, Grim and Hid with the apoptosis inhibitor DIAP1. Our preliminary data suggests-that this model is oversimplified. We propose to use a combination of genetic and biochemical strategies to test alternative models for Rpr and Hid interactions with DIAPI. The differential expression patterns of rpr, grim and hid suggest that they have unique functions in regulating developmental apoptosis. To examine the requirement for rpr, we have generated a mutant that removes the rpr g. Our preliminary characterization of this mutant has revealed a unique requirement for this gene in the programmed death of neuroblasts. Because the neuroblasts represent a defined population of cells that undergo apoptosis in a rpr-dependent manner, we can focus our investigations on the regulation of the apoptotic program in these cells. Not only are rpr, hid and grim essential for the initiation of apoptosis during development, they also are required for high levels of apoptosis in response to DNA damage in the embryo. Although Drosophila p53 (Dmp53) directly regulates rpr expression, our data indicate that deletion of rpr alone does not block Dmp53-induced apoptosis. In the rpr mutant background we will test other genes for their role in this death, and identify alternative targets of Dmp53. This work will improve our understanding of how p53 induces apoptosis.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM055568-08
Application #
6739687
Study Section
Cell Development and Function Integrated Review Group (CDF)
Program Officer
Zatz, Marion M
Project Start
1997-05-01
Project End
2006-04-30
Budget Start
2004-05-01
Budget End
2005-04-30
Support Year
8
Fiscal Year
2004
Total Cost
$354,650
Indirect Cost
Name
Massachusetts General Hospital
Department
Type
DUNS #
073130411
City
Boston
State
MA
Country
United States
Zip Code
02199
Arya, R; Sarkissian, T; Tan, Y et al. (2015) Neural stem cell progeny regulate stem cell death in a Notch and Hox dependent manner. Cell Death Differ 22:1378-87
Arya, Richa; White, Kristin (2015) Cell death in development: Signaling pathways and core mechanisms. Semin Cell Dev Biol 39:12-9
Sarkissian, Tatevik; Timmons, Allison; Arya, Richa et al. (2014) Detecting apoptosis in Drosophila tissues and cells. Methods 68:89-96
Abdelwahid, Eltyeb; Rolland, Stephane; Teng, Xinchen et al. (2011) Mitochondrial involvement in cell death of non-mammalian eukaryotes. Biochim Biophys Acta 1813:597-607
Thomenius, M; Freel, C D; Horn, S et al. (2011) Mitochondrial fusion is regulated by Reaper to modulate Drosophila programmed cell death. Cell Death Differ 18:1640-50
Tan, Ying; Yamada-Mabuchi, Megumu; Arya, Richa et al. (2011) Coordinated expression of cell death genes regulates neuroblast apoptosis. Development 138:2197-206
Wu, Julie N; Nguyen, Nguyen; Aghazarian, Maral et al. (2010) grim promotes programmed cell death of Drosophila microchaete glial cells. Mech Dev 127:407-17
Krieser, Ronald J; White, Kristin (2009) Inside an enigma: do mitochondria contribute to cell death in Drosophila? Apoptosis 14:961-8
Moon, Nam-Sung; Di Stefano, Luisa; Morris, Erick J et al. (2008) E2F and p53 induce apoptosis independently during Drosophila development but intersect in the context of DNA damage. PLoS Genet 4:e1000153
Tseng, Ai-Sun Kelly; Tapon, Nicolas; Kanda, Hiroshi et al. (2007) Capicua regulates cell proliferation downstream of the receptor tyrosine kinase/ras signaling pathway. Curr Biol 17:728-33

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