Mutant proteins containing an expanded polyglutamine tract induce cell death and cause neurodegenerative diseases. These toxic proteins interfere with a variety of physiological pathways, but the key interactions between the toxins and cellular factors remain unclear. To model the diseases in Drosophila, the GMR-Gal4/UAS gene expression system has been used extensively, which operates in the eyes. By using the system, genome-wide studies have resulted in the isolation of functionally diverse groups of Drosophila genes that interact with the disease proteins. We previously reported that coexpressing the Drosophila Dikar gene and an expanded polyglutamine tract by GMR-Gal4/UAS induced a synthetic lethality. We carried out follow-up experiments to isolate additional synthetic lethal alleles. Our data provide evidence that synthetic lethality associated with expressing an expanded polyglutamine tract is more common than thought to be and could have escaped the conventional genetic screens. Our results also suggest that 1) the gene expression system is leaky, allowing expression outside of the primary target eye cell types; 2) expressing an expanded polyglutamine tract is extremely toxic to cells; and 3) combining the leaky expression and the toxicity results in a lethal-prone condition. Thus, genetic modifications to the disease proteins’ acute toxicity could frequently lead to synthetic lethality. However, synthetic lethal alleles are excluded from most conventional screens, necessitating alternative approaches such as a two-step method used in this study to isolate the modifiers. Since synthetic lethality reflects essential genetic buffering networks, studying these alleles may hold the keys to identify the critical interactions in the disease development between the toxic proteins and the physiological pathways.
References
[1]
Orr, H.T. and Zoghbi, H.Y. (2007) Trinucleotide Repeat Disorders. Annual Review of Neuroscience, 30, 575-621. http://dx.doi.org/10.1146/annurev.neuro.29.051605.113042
[2]
Yu, Z. and Bonini, N.M. (2011) Modeling Human Trinucleotide Repeat Diseases in Drosophila. International Review of Neurobiology, 99, 191-212. http://dx.doi.org/10.1016/b978-0-12-387003-2.00008-2
[3]
Figiel, M., Szlachcic, W.J., Switonski, P.M., Gabka, A. and Krzyzosiak, W.J. (2012) Mouse Models of Polyglutamine Diseases: Review and Data Table. Part I. Molecular Neurobiology, 46, 393-429. http://dx.doi.org/10.1007/s12035-012-8315-4
[4]
Blum, E.S., Schwendeman, A.R. and Shaham, S. (2012) PolyQ Disease: Misfiring of a Developmental Cell Death Program? Trends in Cell Biology, 23, 168-174.
[5]
Costa Mdo, C. and Paulson, H.L. (2012) Toward Understanding Machado-Joseph Disease. Progress in Neurobiology, 97, 239-257. http://dx.doi.org/10.1016/j.pneurobio.2011.11.006
[6]
Knott, A.B., Perkins, G., Schwarzenbacher, R. and Bossy-Wetzel, E. (2008) Mitochondrial Fragmentation in Neurodegeneration. Nature Reviews Neuroscience, 9, 505-518. http://dx.doi.org/10.1038/nrn2417
[7]
Sugars, K.L. and Rubinsztein, D.C. (2003) Transcriptional Abnormalities in Huntington Disease. Trends in Genetics, 19, 233-238. http://dx.doi.org/10.1016/S0168-9525(03)00074-X
[8]
Mangiarini, L., Sathasivam, K., Seller, M., Cozens, B., Harper, A., Hetherington, C., Lawton, M., Trottier, Y., Lehrach, H., Davies, S.W., et al. (1996) Exon 1 of the HD Gene with an Expanded CAG Repeat Is Sufficient to Cause a Progressive Neurological Phenotype in Transgenic Mice. Cell, 87, 493-506. http://dx.doi.org/10.1016/S0092-8674(00)81369-0
[9]
Marsh, J.L., Walker, H., Theisen, H., Zhu, Y.Z., Fielder, T., Purcell, J. and Thompson, L.M. (2000) Expanded Polyglutamine Peptides Alone Are Intrinsically Cytotoxic and Cause Neurodegeneration in Drosophila. Human Molecular Genetics, 9, 13-25. http://dx.doi.org/10.1093/hmg/9.1.13
[10]
Brignull, H.R., Moore, F.E., Tang, S.J. and Morimoto, R.I. (2006) Polyglutamine Proteins at the Pathogenic Threshold Display Neuron-Specific Aggregation in a Pan-Neuronal Caenorhabditiselegans Model. Journal of Neuroscience, 26, 7597-7606. http://dx.doi.org/10.1523/JNEUROSCI.0990-06.2006
[11]
Ellerby, L.M., Andrusiak, R.L., Wellington, C.L., Hackam, A.S., Propp, S.S., Wood, J.D., Sharp, A.H., Margolis, R.L., Ross, C.A., Salvesen, G.S., et al. (1999) Cleavage of Atrophin-1 at Caspase Site Aspartic Acid 109 Modulates Cytotoxicity. Journal of Biological Chemistry, 274, 8730-8736. http://dx.doi.org/10.1074/jbc.274.13.8730
[12]
Goti, D., Katzen, S.M., Mez, J., Kurtis, N., Kiluk, J., Ben-Haiem, L., Jenkins, N.A., Copeland, N.G., Kakizuka, A., Sharp, A.H., et al. (2004) A Mutant Ataxin-3 Putative-Cleavage Fragment in Brains of Machado-Joseph Disease Patients and Transgenic Mice Is Cytotoxic above a Critical Concentration. Journal of Neuroscience, 24, 10266-10279. http://dx.doi.org/10.1523/JNEUROSCI.2734-04.2004
[13]
Jung, J., Xu, K.Q., Lessing, D. and Bonini, N.M. (2009) Preventing Ataxin-3 Protein Cleavage Mitigates Degeneration in a Drosophila Model of SCA3. Human Molecular Genetics, 18, 4843-4852. http://dx.doi.org/10.1093/hmg/ddp456
[14]
van Ham, T.J., Breitling, R., Swertz, M.A. and Nollen, E.A. (2009) Neurodegenerative Diseases: Lessons from Genome-Wide Screens in Small Model Organisms. EMBO Molecular Medicine, 1, 360-370. http://dx.doi.org/10.1002/emmm.200900051
[15]
Blum, E.S., Schwendeman, A.R. and Shaham, S. (2013) PolyQ Disease: Misfiring of a Developmental Cell Death Program? Trends in Cell Biology, 23, 168-174. http://dx.doi.org/10.1016/j.tcb.2012.11.003
[16]
Switonski, P.M., Szlachcic, W.J., Gabka, A., Krzyzosiak, W.J. and Figiel, M. (2012) Mouse Models of Polyglutamine Diseases in Therapeutic Approaches: Review and Data Table. Part II. Molecular Neurobiology, 46, 430-466. http://dx.doi.org/10.1007/s12035-012-8316-3
[17]
Jackson, G.R. (2008) Guide to Understanding Drosophila Models of Neurodegenerative Diseases. PLoS Biology, 6, e53.
[18]
Warrick, J.M., Paulson, H.L., Gray-Board, G.L., Bui, Q.T., Fischbeck, K.H., Pittman, R.N. and Bonini, N.M. (1998) Expanded Polyglutamine Protein Forms Nuclear Inclusions and Causes Neural Degeneration in Drosophila. Cell, 93, 939-949. http://dx.doi.org/10.1016/S0092-8674(00)81200-3
[19]
Wernet, M.F., Labhart, T., Baumann, F., Mazzoni, E.O., Pichaud, F. and Desplan, C. (2003) Homothorax Switches Function of Drosophila Photoreceptors from Color to Polarized Light Sensors. Cell, 115, 267-279. http://dx.doi.org/10.1016/S0092-8674(03)00848-1
[20]
Halfon, M.S., Gisselbrecht, S., Lu, J., Estrada, B., Keshishian, H. and Michelson, A.M. (2002) New Fluorescent Protein Reporters for Use with the Drosophila Gal4 Expression System and for Vital Detection of Balancer Chromosomes. Genesis, 34, 135-138. http://dx.doi.org/10.1002/gene.10136
[21]
Li, L.B. and Bonini, N.M. (2010) Roles of Trinucleotide-Repeat RNA in Neurological Disease and Degeneration. Trends in Neurosciences, 33, 292-298. http://dx.doi.org/10.1016/j.tins.2010.03.004
[22]
Zhang, P., Wang, Q.M., Hughes, H. and Intrieri, G. (2014) Synthetic Lethality Induced by a Strong Drosophila Enhancer of Expanded Polyglutamine Tract. Open Journal of Genetics, 4, 300-315. http://dx.doi.org/10.4236/ojgen.2014.44028
[23]
Thibault, S.T., Singer, M.A., Miyazaki, W.Y., Milash, B., Dompe, N.A., Singh, C.M., Buchholz, R., Demsky, M., Fawcett, R., Francis-Lang, H.L., et al. (2004) A Complementary Transposon Tool Kit for Drosophila melanogaster using P and Piggy Bac. Nature Genetics, 36, 283-287. http://dx.doi.org/10.1038/ng1314
[24]
Spradling, A.C., Stern, D.M., Kiss, I., Roote, J., Laverty, T. and Rubin, G.M. (1995) Gene Disruptions Using P Transposable Elements: An Integral Component of the Drosophila Genome Project. Proceedings of the National Academy of Sciences of the United States of America, 92, 10824-10830. http://dx.doi.org/10.1073/pnas.92.24.10824
[25]
Timakov, B., Liu, X., Turgut, I. and Zhang, P. (2002) Timing and Targeting of P-Element Local Transposition in the Male Germline Cells of Drosophila melanogaster. Genetics, 160, 1011-1022.
[26]
Sudi, J., Zhang, S., Intrieri, G., Hao, X.M. and Zhang, P. (2008) Coincidence of P-Insertion Sites and Breakpoints of Deletions Induced by Activating P Elements in Drosophila. Genetics, 179, 227-235. http://dx.doi.org/10.1534/genetics.107.085498
[27]
Freeman, M. (1997) Personal Communication to FlyBase. http://flybase.org/reports/FBrf0091569.html
[28]
Steffan, J.S., Agrawal, N., Pallos, J., Rockabrand, E., Trotman, L.C., Slepko, N., Illes, K., Lukacsovich, T., Zhu, Y.Z., Cattaneo, E., et al. (2004) SUMO Modification of Huntingtin and Huntington’s Disease Pathology. Science, 304, 100-104. http://dx.doi.org/10.1126/science.1092194
[29]
Kazemi-Esfarjani, P. and Benzer, S. (2000) Genetic Suppression of Polyglutamine Toxicity in Drosophila. Science, 287, 1837-1840. http://dx.doi.org/10.1126/science.287.5459.1837
[30]
Brand, A.H., Manoukian, A.S. and Perrimon, N. (1994) Ectopic Expression in Drosophila. Methods in Cell Biology, 44, 635-654.
[31]
Yeh, P.-A., Yang, W.-H., Chiang, P.-Y., Wang, S.-C., Chang, M.-S. and Chang, C.-J. (2012) Drosophila Eyes Absent Is a Novel mRNA Target of the Tristetraprolin (TTP) Protein DTIS11. International Journal of Biological Sciences, 8, 606-619. http://dx.doi.org/10.7150/ijbs.3782
[32]
Duffy, J.B. (2002) GAL4 System in Drosophila: A Fly Geneticist’s Swiss Army Knife. Genesis, 34, 1-15. http://dx.doi.org/10.1002/gene.10150
[33]
Fernandez-Funez, P., Nino-Rosales, M.L., de Gouyon, B., She, W.C., Luchak, J.M., Martinez, P., Turiegano, E., Benito, J., Capovilla, M., Skinner, P.J., et al. (2000) Identification of Genes That Modify Ataxin-1-Induced Neurodegeneration. Nature, 408, 101-106. http://dx.doi.org/10.1038/35040584
[34]
Bilen, J. and Bonini, N.M. (2007) Genome-Wide Screen for Modifiers of Ataxin-3 Neurodegeneration in Drosophila. PLoS Genetics, 3, 1950-1964. http://dx.doi.org/10.1371/journal.pgen.0030177
[35]
Zhang, S., Binari, R., Zhou, R. and Perrimon, N. (2010) A Genomewide RNA Interference Screen for Modifiers of Aggregates Formation by Mutant Huntingtin in Drosophila. Genetics, 184, 1165-1179. http://dx.doi.org/10.1534/genetics.109.112516
[36]
Vossfeldt, H., Butzlaff, M., Prussing, K., Ni Charthaigh, R.A., Karsten, P., Lankes, A., Hamm, S., Simons, M., Adryan, B., Schulz, J.B., et al. (2012) Large-Scale Screen for Modifiers of Ataxin-3-Derived Polyglutamine-Induced Toxicity in Drosophila. PLoS ONE, 7, e47452. http://dx.doi.org/10.1371/journal.pone.0047452
[37]
Moses, K. and Rubin, G.M. (1991) Glass Encodes a Site-Specific DNA-Binding Protein That Is Regulated in Response to Positional Signals in the Developing Drosophila Eye. Genes & Development, 5, 583-593. http://dx.doi.org/10.1101/gad.5.4.583
[38]
Ellis, M.C., O’Neill, E.M. and Rubin, G.M. (1993) Expression of Drosophila Glass Protein and Evidence for Negative Regulation of Its Activity in Non-Neuronal Cells by Another DNA-Binding Protein. Development, 119, 855-865.
[39]
Mukhopadhyay, M. and Campos, A.R. (1995) The Larval Optic Nerve Is Required for the Development of an Identified Serotonergic Arborization in Drosophila melanogaster. Developmental Biology, 169, 629-643. http://dx.doi.org/10.1006/dbio.1995.1175
[40]
de Velasco, B., Erclik, T., Shy, D., Sclafani, J., Lipshitz, H., McInnes, R. and Hartenstein, V. (2007) Specification and Development of the Pars Intercerebralis and Pars Lateralis, Neuroendocrine Command Centers in the Drosophila Brain. Developmental Biology, 302, 309-323. http://dx.doi.org/10.1016/j.ydbio.2006.09.035
[41]
Moses, K., Ellis, M.C. and Rubin, G.M. (1989) The Glass Gene Encodes a Zinc-Finger Protein Required by Drosophila Photoreceptor Cells. Nature, 340, 531-536. http://dx.doi.org/10.1038/340531a0
[42]
Rebay, I., Chen, F., Hsiao, F., Kolodziej, P.A., Kuang, B.H., Laverty, T., Suh, C., Voas, M., Williams, A. and Rubin, G.M. (2000) A Genetic Screen for Novel Components of the Ras/Mitogen-Activated Protein Kinase Signaling Pathway That Interact with the Yan Gene of Drosophila Identifies Split Ends, a New RNA Recognition Motif-Containing Protein. Genetics, 154, 695-712.
[43]
Imarisio, S., Carmichael, J., Korolchuk, V., Chen, C.W., Saiki, S., Rose, C., Krishna, G., Davies, J.E., Ttofi, E., Underwood, B.R., et al. (2008) Huntington’s Disease: From Pathology and Genetics to Potential Therapies. Biochemical Journal, 412, 191-209. http://dx.doi.org/10.1042/BJ20071619
[44]
Poirier, M.A., Jiang, H.B. and Ross, C.A. (2005) A Structure-Based Analysis of Huntingtin Mutant Polyglutamine Aggregation and Toxicity: Evidence for a Compact Beta-Sheet Structure. Human Molecular Genetics, 14, 765-774. http://dx.doi.org/10.1093/hmg/ddi071
[45]
Hartman IV, J.L., Garvik, B. and Hartwell, L. (2001) Principles for the Buffering of Genetic Variation. Science, 291, 1001-1004.
[46]
Tong, A.H., Lesage, G., Bader, G.D., Ding, H.M., Xu, H., Xin, X.F., Young, J., Berriz, G.F., Brost, R.L., Chang, M., et al. (2004) Global Mapping of the Yeast Genetic Interaction Network. Science, 303, 808-813. http://dx.doi.org/10.1126/science.1091317
[47]
Ooi, S.L., Pan, X.W., Peyser, B.D., Ye, P., Meluh, P.B., Yuan, D.S., Irizarry, R.A., Bader, J.S., Spencer, F.A. and Boeke, J.D. (2006) Global Synthetic-Lethality Analysis and Yeast Functional Profiling. Trends Genet, 22, 56-63. http://dx.doi.org/10.1016/j.tig.2005.11.003
[48]
Ye, P., Peyser, B.D., Pan, X.W., Boeke, J.D., Spencer, F.A. and Bader, J.S. (2005) Gene Function Prediction from Congruent Synthetic Lethal Interactions in Yeast. MolSystBiol, 1, 0026.
