351
|
Cockett M, Dracopoli N, Sigal E. Applied genomics: integration of the technology within pharmaceutical research and development. Curr Opin Biotechnol 2000; 11:602-9. [PMID: 11102797 DOI: 10.1016/s0958-1669(00)00151-8] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Multiple novel technologies have recently been developed to improve the analysis of genetic sequences, to rapidly assess RNA or protein levels in relevant tissues, and to validate function of potential new drug targets. The challenge facing pharmaceutical research is one of effective integration of these new technologies in ways that can maximally affect the discovery and development pipeline. Although database mining and transcriptional profiling clearly have increased the number of putative targets, the current focus is to assign function to new gene targets in a high-throughput manner. This requires a restructuring of the classical linear progression from gene identification, functional elucidation, target validation and screen development. New approaches are called for that can make this process non-linear and high-throughput.
Collapse
Affiliation(s)
- M Cockett
- Applied Genomics, Bristol-Myers Squibb, 311 Pennington-Rocky Hill Road, Pennington, NJ 08534, USA
| | | | | |
Collapse
|
352
|
Abstract
The tumor suppressor, p53, is among the most commonly mutated genes in human cancers. Recent reports describe shared and divergent properties of a Drosophila p53 homolog Dmp53. Like its mammalian counterpart, Dmp53 also functions in damage-induced cell death. In this model system, the apoptosis activator reaper has emerged as an important target gene. Together with the wealth of genomic data available in Drosophila, continued studies on Dmp53 promise new insights into the regulation and function of this important gene family.
Collapse
Affiliation(s)
- W Nordstrom
- Department of Cell Biology, University of Texas, Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9039, USA
| | | |
Collapse
|
353
|
Bangs P, Franc N, White K. Molecular mechanisms of cell death and phagocytosis in Drosophila. Cell Death Differ 2000; 7:1027-34. [PMID: 11139274 DOI: 10.1038/sj.cdd.4400754] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
The genetic tools available in Drosophila have facilitated our understanding of how apoptosis is regulated and executed in the context of the developing organism. All embryonic apoptosis is initiated by the activity of three genes, rpr, grim and hid. Each of these genes is independently regulated, allowing developmental apoptosis to be finely controlled. These initiators in turn activate the core apoptotic machinery, including the caspases. Drosophila counterparts to other conserved components of the apoptotic machinery have been recently identified, and we discuss how these may be integrated into the process of normal developmentally regulated cell death. We also outline the role that phagocytosis plays in the final stages of apoptosis and consider the molecular mechanisms guiding the elimination of apoptotic corpses.
Collapse
Affiliation(s)
- P Bangs
- Cutaneous Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA
| | | | | |
Collapse
|
354
|
|
355
|
Abstract
DNA damage frequently triggers death by apoptosis. The irreversible decision to die can be facilitated or forestalled through integration of a wide variety of stimuli from within and around the cell. Here we address some fundamental questions that arise from this model. Why should DNA damage initiate apoptosis in the first place? In damaged cells, what are the alternatives to death and why should they be selected in some circumstances but not others? What signals register DNA damage and how do they impinge on the effector pathways of apoptosis? Is there a suborganellar apoptosome complex effecting the integration of death signals within the nucleus, just as there is in the cytoplasm? And what are the consequences of failure to initiate apoptosis in response to DNA damage?
Collapse
Affiliation(s)
- T Rich
- Department of Pathology, University of Cambridge, UK
| | | | | |
Collapse
|
356
|
Abstract
Essential to the construction, maintenance and repair of tissues is the ability to induce suicide of supernumerary, misplaced or damaged cells with high specificity and efficiency. Study of three principal organisms--the nematode, fruitfly and mouse--indicate that cell suicide is implemented through the activation of an evolutionarily conserved molecular programme intrinsic to all metazoan cells. Dysfunctions in the regulation or execution of cell suicide are implicated in a wide range of developmental abnormalities and diseases.
Collapse
Affiliation(s)
- P Meier
- Signal Transduction Laboratory, Imperial Cancer Research Fund, London, UK.
| | | | | |
Collapse
|
357
|
Abstract
The p53 tumor suppressor gene is a sequence-specific transcription factor that activates the expression of genes engaged in promoting growth arrest or cell death in response to genotoxic stress. A possible role for p53-related modulation of neuronal viability has been suggested by the finding that p53 expression is elevated in damaged neurons in acute models of injury such as ischemia and epilepsy and in brain tissue samples derived from patients with chronic neurodegenerative diseases. Moreover, the absence of p53 has been shown to protect neurons from a wide variety of acute toxic insults. Signal transduction pathways associated with p53-induced cell death are being unraveled and suggest that intervention may prove fruitful in maintaining neuronal viability and restoring function following cytopathic insults.
Collapse
Affiliation(s)
- R S Morrison
- Department of Neurological Surgery, University of Washington School of Medicine, Box 356470, Seattle, Washington 98195-6470, USA
| | | |
Collapse
|
358
|
Abstract
Programmed cell death plays an important role in maintaining homeostasis during animal development, and has been conserved in animals as different as nematodes and humans. Recent studies of Drosophila have provided valuable information toward our understanding of genetic regulation of death. Different signals trigger the novel death regulators rpr, hid, and grim, that utilize the evolutionarily conserved iap and ark genes to modulate caspase function. Subsequent removal of dying cells also appears to be accomplished by conserved mechanisms. The similarity between Drosophila and human in cell death signaling pathways illustrate the promise of fruit flies as a model system to elucidate the mechanisms underlying regulation of programmed cell death.
Collapse
Affiliation(s)
- C Y Lee
- Center for Agricultural Biotechnology, University of Maryland Biotechnology Institute, Department of Biology, University of Maryland, College Park 20742, USA
| | | |
Collapse
|
359
|
Sekelsky JJ, Brodsky MH, Burtis KC. DNA repair in Drosophila: insights from the Drosophila genome sequence. J Cell Biol 2000; 150:F31-6. [PMID: 10908583 PMCID: PMC2180214 DOI: 10.1083/jcb.150.2.f31] [Citation(s) in RCA: 101] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
- Jeff J. Sekelsky
- Department of Biology, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Michael H. Brodsky
- Howard Hughes Medical Institute, University of California, Berkeley, California 94720
| | - Kenneth C. Burtis
- Section of Molecular and Cellular Biology, University of California, Davis, Davis, California 95616
| |
Collapse
|
360
|
Fortini ME, Skupski MP, Boguski MS, Hariharan IK. A survey of human disease gene counterparts in the Drosophila genome. J Cell Biol 2000; 150:F23-30. [PMID: 10908582 PMCID: PMC2180233 DOI: 10.1083/jcb.150.2.f23] [Citation(s) in RCA: 154] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2000] [Accepted: 06/26/2000] [Indexed: 11/22/2022] Open
Affiliation(s)
- M E Fortini
- Department of Genetics, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA.
| | | | | | | |
Collapse
|
361
|
|
362
|
Du C, Fang M, Li Y, Li L, Wang X. Smac, a mitochondrial protein that promotes cytochrome c-dependent caspase activation by eliminating IAP inhibition. Cell 2000; 102:33-42. [PMID: 10929711 DOI: 10.1016/s0092-8674(00)00008-8] [Citation(s) in RCA: 2395] [Impact Index Per Article: 99.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
We report here the identification of a novel protein, Smac, which promotes caspase activation in the cytochrome c/Apaf-1/caspase-9 pathway. Smac promotes caspase-9 activation by binding to inhibitor of apoptosis proteins, IAPs, and removing their inhibitory activity. Smac is normally a mitochondrial protein but is released into the cytosol when cells undergo apoptosis. Mitochondrial import and cleavage of its signal peptide are required for Smac to gain its apoptotic activity. Overexpression of Smac increases cells' sensitivity to apoptotic stimuli. Smac is the second mitochondrial protein, along with cytochrome c, that promotes apoptosis by activating caspases.
Collapse
Affiliation(s)
- C Du
- Howard Hughes Medical Institute and Department of Biochemistry, University of Texas Southwestern Medical Center at Dallas, 75235, USA
| | | | | | | | | |
Collapse
|
363
|
Jin S, Martinek S, Joo WS, Wortman JR, Mirkovic N, Sali A, Yandell MD, Pavletich NP, Young MW, Levine AJ. Identification and characterization of a p53 homologue in Drosophila melanogaster. Proc Natl Acad Sci U S A 2000; 97:7301-6. [PMID: 10860994 PMCID: PMC16540 DOI: 10.1073/pnas.97.13.7301] [Citation(s) in RCA: 163] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The tumor suppressor gene p53 in mammalian cells plays a critical role in safeguarding the integrity of genome. It functions as a sequence-specific transcription factor. Upon activation by a variety of cellular stresses, p53 transactivates downstream target genes, through which it regulates cell cycle and apoptosis. However, little is known about p53 in invertebrates. Here we report the identification and characterization of a Drosophila p53 homologue gene, dp53. dp53 encodes a 385-amino acid protein with significant homology to human p53 (hp53) in the region of the DNA-binding domain, and to a lesser extent the tetramerization domain. Purified dp53 DNA-binding domain protein was shown to bind to the consensus hp53-binding site by gel mobility analysis. In transient transfection assays, expression of dp53 in Schneider cells transcriptionally activated promoters that contained consensus hp53-responsive elements. Moreover, a mutant dp53 (Arg-155 to His-155), like its hp53 counterpart mutant, exerted a dominant-negative effect on transactivation. Ectopic expression of dp53 in Drosophila eye disk caused cell death and led to a rough eye phenotype. dp53 is expressed throughout the development of Drosophila with highest expression levels in early embryogenesis, which has a maternal component. Consistent with this, dp53 RNA levels were high in the nurse cells of the ovary. It appears that p53 is structurally and functionally conserved from flies to mammals. Drosophila will provide a useful genetic system to the further study of the p53 network.
Collapse
Affiliation(s)
- S Jin
- Laboratory of Cancer Biology, Genetics, and Molecular Biophysics, Rockefeller University, 1230 York Avenue, New York, NY 10021, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
364
|
Weitzman J. Fruit fly p53 and cell death. Genome Biol 2000. [DOI: 10.1186/gb-2000-1-2-reports0053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
|
365
|
Abstract
The recent discovery of a Drosophila orthologue of the p53 tumour suppressor promises new insights into the complex function, regulation and evolution of one of the most intensely studied human disease proteins.
Collapse
|
366
|
Ollmann M, Young LM, Di Como CJ, Karim F, Belvin M, Robertson S, Whittaker K, Demsky M, Fisher WW, Buchman A, Duyk G, Friedman L, Prives C, Kopczynski C. Drosophila p53 is a structural and functional homolog of the tumor suppressor p53. Cell 2000; 101:91-101. [PMID: 10778859 DOI: 10.1016/s0092-8674(00)80626-1] [Citation(s) in RCA: 322] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The importance of p53 in carcinogenesis stems from its central role in inducing cell cycle arrest or apoptosis in response to cellular stresses. We have identified a Drosophila homolog of p53 ("Dmp53"). Like mammalian p53, Dmp53 binds specifically to human p53 binding sites, and overexpression of Dmp53 induces apoptosis. Importantly, inhibition of Dmp53 function renders cells resistant to X ray-induced apoptosis, suggesting that Dmp53 is required for the apoptotic response to DNA damage. Unlike mammalian p53, Dmp53 appears unable to induce a G1 cell cycle block when overexpressed, and inhibition of Dmp53 activity does not affect X ray-induced cell cycle arrest. These data reveal an ancestral proapoptotic function for p53 and identify Drosophila as an ideal model system for elucidating the p53 apoptotic pathway(s) induced by DNA damage.
Collapse
Affiliation(s)
- M Ollmann
- Exelixis, Inc., South San Francisco, California 94080, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
367
|
Abstract
The characterization of complex cellular responses to diverse stimuli can be studied by the use of emerging chip-based technologies.
Collapse
Affiliation(s)
- D P Harkin
- Department of Oncology, The Queens University, Belfast City Hospital, Belfast, BT97AB, UK.
| | | |
Collapse
|