Role of the ubiquitin/proteasome pathway in Drosophila development: spermatogenesis, mechanisms of sperm competition.
Proteasomes are large, multi-subunit complexes that act as the proteolytic core of the ubiquitin-dependent protein degrading machinery, and are responsible for the removal of abnormal polypeptides and short lived regulatory proteins from eukaryotic cells. Recent work, using the tools of biochemistry and cell biology, has revealed much about the physical and biochemical properties of proteasomes, but many aspects of their biological function remain unclear.
As an approach toward learning more about the role of proteasome-mediated proteolysis during metazoan development, my lab has initiated a genetic and molecular study of Drosophila proteasomes. Our work is focused on two major questions:
What is the role of the ubiquitin-proteasome pathway in specific developmental processes?
Are there structurally distinct cell-type specific proteasomes that have specialized functions?
To address the first question we have taken a mutational approach. We have isolated and characterized two dominant temperature-sensitive proteasome mutants (DTS5 and DTS7) that can be used to disrupt proteasome function in vivo, and are using them to examine their effects on specific biological processes.
For the second question, we have used a reverse genetics approach. We have identified and characterized five proteasome subunit genes that are expressed exclusively in the male germline. A combination of molecular, cell biological, and genetic approaches are being used to investigate the importance of proteasome-mediated protein degradation in spermatogenesis, and to address the functional role of the testes-specific subunits in this process.
Undergraduate Research Opportunities
My major research interests involve the genetic control of development and the molecular mechanisms of gene regulation using the fruitfly, Drosophila melanogaster, as an experimental organism to investigate these topics.
Specifically, we have been investigating a number of genes that encode components of a structure called the proteasome. Proteasomes are multisubunit complexes that act as the protein-degrading machinery in all eukaryotes. By analyzing mutant strains that have defective proteasomes, and by examining the molecular characteristics of cloned proteasome subunit genes, we are attempting to clarify what specific roles proteasome function plays during development.
Restrictions: I would be hesitant to take on anyone who has not done reasonably well in General Genetics (B or better).
- Postdoctoral Fellow, University of California, San Diego (1979-1985)
- Ph.D., University of North Carolina, Chapel Hill (1979)
- B.A., Murray State University (1973)
- BIO 326: Genetics
- BIO 400/600: Model Organism Genetics
- BIO 419: Junior/Senior Thesis Seminar
BIO 326: Genetics & Cell Biology I
Taught Fall semesters
Principles of inheritance, structure and synthesis of nucleic acids and proteins, basic enzymology, microbial genetics, recombinant DNA technology and introduction to genomics.
BIO 419 Honors Seminar
Taught every semester
A discussion-student presentation format course designed to introduce highly qualified students to biological research. Faculty in the Biology Department present overviews on their research programs and the students present progress reports on their honors thesis research. The course is designed to open communication among people with interests in biological research.
BIO 435 Genetics Laboratory
Taught Fall semesters (co-taught with Dr. Erdman)
The general purpose of this course is to allow students to gain experience in conducting analysis using genetic methods. In this course we will use three of the organisms that have been of fundamental importance in the development of our understanding of genetic principles. These are: the bacteriophage, T4; the bacterium, E.coli; and the fruit fly, Drosophila melanogaster. All students will carry out a series of experiments investigating various aspects of genetic analysis using the research organisms listed above. Three lab reports and four quizzes will be required.
BIO 462/662 Molecular Genetics
Taught Fall semesters (co-taught with Dr. Raina and Dr. Erdman)
Applications of recombinant DNA methodology to the study of gene function. Mechanisms regulating protein function and gene expression. Overview of the molecular causes of spontaneous and inherited diseases. Introduction to genomic and proteomic methods.
Interdisciplinary Programs Selected Publications
Droge-Young, E. M., Manier, M. K., Lüpold, S., Belote, J. M., & Pitnick, S. (2012). Covariance among premating, post-copulatory and viability fitness components in drosophila melanogaster and their influence on paternity measurement. Journal of Evolutionary Biology, in press.
Manier, M. K., J. M. Belote, K. S. Berben, D. Novikov, W. T. Stuart and S. S. Pitnick (2010) Resolving mechanisms of competitive fertilization success in Drosophila melanogaster. Science 328: 354-357.
Belote, J.M. and L. Zhong (2009) Duplicated proteasome genes in Drosophila and their roles in spermatogenesis. Heredity 103: 23-31.
Maxwell, P.H., J. M. Belote and R.W. Levis (2008) Developmental and tissue-specific accumulation pattern for the Drosophila melanogaster TART ORF1 protein. Gene 415: 32-39.
Zhong, L. and J.M. Belote (2007) The testis-specific proteasome subunit Prosa6T of Drosophila melanogaster is required for individualization and nuclear maturation during spermatogenesis. Development 134: 3517-3525.
Neuburger, P. J., K. J. Saville, J. Zeng, K. A. Smyth and J.M. Belote (2006) A genetic suppressor of two dominant temperature sensitive (DTS) lethal proteasome mutants of Drosophila melanogaster is itself a mutated proteasome subunit gene. Genetics 173: 1377-1387.
Belote, J.M. and L. Zhong (2005) Proteasome gene duplications in mammals, flies and plants. Recent Research Developments in Genes & Genomes 1:107-129.
Ma, J., E. Katz, and J.M. Belote. (2002) Expression of proteasome subunit isoforms during spermatogenesis in Drosophila melanogaster. Insect Molec. Biol. 11: 624-639.
Belote, J.M. and E. Fortier (2002) Targeted expression of dominant negative proteasome mutants inDrosophila. Genesis 34:80-82.
Fortier, E. and J. M. Belote (2000) Temperature-dependent gene silencing by an expressed inverted repeat in Drosophila. Genesis 26:240-244.
Covi, J. A., J. M. Belote and D. L. Mykles (1999) Subunit compositions and catalytic properties of proteasomes from developmental temperature-sensitive mutants of Drosophila melanogaster. Arch. Biochem. Biophys. 368: 85-97.
Smyth, K. A. and J. M. Belote (1999) The dominant temperature-sensitive lethal mutant DTS7 ofDrosophila melanogaster encodes an altered 20S proteasome ß-type subunit. Genetics 151: 211-220.
Belote, J.M., M. Miller and K.A. Smyth (1998) Evolutionary conservation of a testes-specific proteasome subunit gene in Drosophila. Gene 215: 93-100.
Smith, E. R., J. M. Belote, R. L. Schiltz, X.-J. Yang, P. A. Moore, S. L. Berger, Y. Nakatani and C. D. Allis (1998) Cloning of Drosophila GCN5: conserved features among metazoan GCN5 family members. Nucl. Acids Res 26, 2948-2954.
Cheng, L., N. Roemer, K.A. Smyth, J.M. Belote, J. Nambu and L.M. Schwartz (1998) Cloning and characterization of Pros45, the Drosophila SUG-1 proteasome subunit homolog. Mol. Gen. Genet 259, 13-20.
Zaiss, D. and J. M. Belote (1997) Molecular cloning of the Drosophila melanogaster gene a5_dmencoding a 20S proteasome a-type subunit. Gene 201, 99-105.
Yuan, X., M. Miller and J. M. Belote (1996) Duplicated proteasome subunit genes in Drosophila melanogaster encoding testes-specific isoforms. Genetics 144: 147-157.
Liu, Y. and J. M. Belote (1995) Protein-protein interactions among components of the primary sex determination signal of Drosophila. Mol. Gen. Genetics 248: 182-189.
Samuel, D. S., J. M. Belote and S. H. P. Chan (1995) Isolation of the rat F1- ATPase inhibitor gene and its pseudogenes. Biochim. Biophys. Acta 1230: 81-85.
Yuan, X. and J. Belote (1995) Determination of the molecular lesions associated with loss-of-functiontransformer alleles of Drosophila melanogaster. Biochim. Biophys. Acta 1260: 369-370.
Saville, K. J. and J. M. Belote (1993) Identification of an essential gene, l(3)73Ai, with a dominant temperature-sensitive lethal allele, encoding a Drosophila proteasome subunit. Proc. Natl. Acad. Sci.(USA) 90: 8842-8846.
Belote, J. M. (1992) Sex determination in Drosophila melanogaster: from the X:A ratio to doublesex.Seminars in Developmental Biology 3: 319-330.
O'Neil, M. T. and J. M. Belote (1992) Interspecific comparison of the transformer gene of Drosophilareveals an unusually high degree of evolutionary divergence. Genetics 131: 113-128.
Belote, J. M. (1992) Molecular genetics of sex determination in Drosophila melanogaster. In: Molecular Approaches to Pure and Applied Entomology. eds. M.J. Whitten and J.G. Oakeshott. (Springer-Verlag New York, Inc., New York). pp. 292-328.
Belote, J. M., F. M. Hoffmann, M. McKeown, R. L. Chorsky, and B. S. Baker (1990) Cytogenetics of chromosome region 73AD of Drosophila melanogaster. Genetics, 125: 783-793.
Belote, J. M. (1989) The control of sexual development in Drosophila melanogaster: Genetic and molecular analysis of a genetic regulatory hierarchy. Gene 82, 161-167.
Sosnowski, B. A., J. M. Belote, and M. McKeown.(1989) Sex-specific alternative splicing of RNA from thetransformer gene results from sequence-dependent splice site blockage. Cell 58, 449-459.
Belote, J. M., M. McKeown, R. T. Boggs, R. Ohkawa, and B. A. Sosnowski. (1989) The molecular genetics of transformer, a genetic switch controlling sexual differentiation in Drosophila. Devel. Genet.10, 143-154..
Tearle, R. G., J. M. Belote, M. McKeown, B. S. Baker and A. J. Howells (1989) Cloning and characterization of the scarlet gene of Drosophila melanogaster. Genetics 122, 595-606.
Nagoshi, R., M. McKeown, K. Burtis, J. M. Belote, and B. S. Baker. (1988) The control of alternative splicing at genes regulating sexual differentiation in D. melanogaster. Cell 53, 229-236.
McKeown, M., J. M. Belote, and R. T. Boggs. (1988) Ectopic expression of the female transformer gene product leads to female differentiation of chromosomally male Drosophila. Cell 53, 887-895.
McKeown, M., R. T. Boggs, K. Nash. R. Ohkawa, B. A. Sosnowski, and J. M. Belote. (1988) The use of germline transformation in the study of sexual differentiation in Drosophila. In Gene Transfer in Animals: UCLA Symposia on Molecular and Cellular Biology, New Series, Volume 87, eds. I. Verma, R. Mulligan, and A. Beauset (Alan R. Liss, Inc., New York).
DiBenedetto, A. J., D. M. Lakich, W. D. Kruger, J. M. Belote, B. S. Baker and M. F. Wolfner (1987) Sequences expressed sex-specifically in D. melanogaster adults. Devel. Biol. 119, 242-251.
McKeown, M., J. M. Belote, and B. S. Baker (1987) A molecular analysis of transformer, a gene inDrosophila melanogaster that controls female sexual differentiation. Cell 48, 489-499.
Boggs, R. T., P. Gregor, S. Idriss, J. M. Belote, and M. McKeown (1987) Regulation of sexual differentiation in D. melanogaster via alternative splicing of RNA from the transformer gene. Cell 50, 739-747.
Belote, J. M. and B. S. Baker (1987) Sexual behavior: Its genetic control during development and adulthood in Drosophila melanogaster. Proc. Natl. Acad. Sci. (USA) 84, 8026-8030.
Belote, J. M., A. M. Handler, M. F. Wolfner, K. J. Livak, and B. S. Baker (1985) The sex specific regulation of yolk protein gene expression in Drosophila melanogaster. Cell 40: 339-348.
Belote, J. M., M. B. McKeown, D. J. Andrew, T. N. Scott, M. F. Wolfner, and B. S. Baker (1985) The control of sexual differentiation in Drosophila melanogaster. Cold Spring Harbor Symp. Quant. Biol. 50: 605-614.
McKeown, M., J. Belote, D. Andrew, N. Scott, M. Wolfner, and B. Baker. (1985) Molecular genetics of sex determination in Drosophila. In: Gametogenesis and the Early Embryo: 44th Symp. Soc. Dev. Biol. ed. J.G. Gall (Allen R. Liss Co., New York) pp 1-17.
Baker, B. S., M. Wolfner, and J. Belote (1984) Sex determination in Drosophila melanogaster. In:Genetics: New Frontiers. Proceedings of the XV International Congress of Genetics. Vol. III. Genetics and Health. eds. V.L. Chopra, B.C. Joshi, R.P. Sharma, H.C. Bansal. Oxford & IBH Publishing Co. New Delhi. pp. 223-232.
Belote, J. M. and B. S. Baker (1983) The dual functions of a sex determination gene in Drosophila melanogaster. Devel. Biol. 95: 512-517.
Baker, B. S. and J. M. Belote (1983) Sex determination and dosage compensation in Drosophila melanogaster. Ann. Rev. Genetics 17: 345-393.
Belote, J. M. (1983) Male-specific lethal mutations of Drosophila melanogaster. II. Parameters of gene action during male development. Genetics 105: 881-896.
Belote, J. M. and B. S. Baker (1982) Sex determination in Drosophila melanogaster: Analysis oftransformer-2, a sex transforming locus. Proc. Natl. Acad. Sci. (USA) 79: 1568-1572.
Belote, J. M. and J. C. Lucchesi (1980) Control of X chromosome transcription by the maleless gene inDrosophila. Nature 285: 573-575.
Belote, J. M. and J. C. Lucchesi (1980) Male-specific lethal mutations of Drosophila melanogaster.Genetics 96: 165-186.
Lucchesi, J. C., J. M. Belote, and G. Maroni (1977) X-linked gene activity in metamales (XY;3A) ofDrosophila. Chromosoma 65: 1-7.
Manley, E. and J. Belote (1972) Comparative depressant activity and interaction of ethanol and pentobarbital in goldfish. J. of Pharmaceutical Sci. 61: 1401-1403.