J. Woodland HastingsDepartment of Molecular & Cellular Biology
Biological Laboratories, Room 4070
16 Divinity Avenue, Cambridge, MA 02138
tel: (617) 495-3714; fax: (617) 496-8726
Dr. Hastings is not taking new graduate students, at this time.
My research is concerned with the molecular components that participate in and regulate the circadian cycle, the so-called "biological clock", and the mechanism of the cellular oscillator itself. The circadian clock controls many overt processes, such as sleep/wake cycle, but in cases analyzed, its fundamental basis involves gene expression.
We are studying a model unicellular dinoflagellate, Gonyaulax, in which we have shown that the circadian expression of bioluminescence involves a daily synthesis and destruction of two proteins involved in the biochemical reaction. However, the mRNA for these proteins remains at the same level day and night, so that the synthesis is controlled at the translational level. This control appears to be involve a protein that binds to the 3' untranslated region of the message; its binding activity decreases at the onset of night, when synthesis of the luminescence system starts, and vice versa, indicating that it functions as a clock-controlled repressor. The binding site of this protein embraces a 22 nt-long region, which contains 7 UG repeats.
Other processes and other proteins in Gonyaulax are also regulated by the circadian clock, some with the maximum activity during the day. Currently we are studying the regulation of these different proteins- this should give insight concerning the molecular mechanism of the circadian clock.
Our laboratory is also studying the cell biology and biochemistry of luminescence in Gonyaulax, the cellular localization and control of the light emitting organelles, and the luciferase gene in this organism. The research also concerns the fundamental aspects of light-emitting reactions, including mechanisms of chemiexcitation and the specific roles of luciferases.
Wilson, T. & Hastings, J.W. (1998) Bioluminescence Annu. Rev. Cell Devel. Biol. 14: 197-230
Hastings, J. W. and Greenberg, E. P. (1999) Quorum Sensing: The explanation of a curious phenomenon reveals a common characteristic of bacteria. J . Bacteriol. 181: 2667-2668.
Fagan, Thomas, Morse, David and Hastings, J. W. (1999) Circadian synthesis of a nuclear-encoded chloroplast glyceraldehyde-3-phosphate dehydrogenase in the dinoflagellate Gonyaulax polyedra is translationally controlled. Biochemistry 38: 7689-7695
Li, Liming, Liu, Liyan, Hong, Robert, Robertson, Deborah and Hastings, J. W. (2001) N-terminal intramolecularly conserved histidines of three domains in Gonylaulax luciferase are responsible for loss of activity in the alkaline region. Biochemistry 40: 1844-1849
Okamoto, O. K., Liu, Liyun, Robertson, D. L. and Hastings, J. Woodland (2001) Members of a Dinoflagellate Luciferase Gene Family Differ in Synonymous Substitution Rates. Biochemistry 40: 15862-15868
Viviani, V. R., Hastings, J. W. and Wilson, T. (2002) Two bioluminescent Diptera: the North American Orfelia fultoni and the Australian Arachnocampa flava. Similar niche, different bioluminescence systems. Photochem. Photobiol. 75: 22-27.
Fagan, Thomas and Hastings, J. W (2002) Phylogenetic Analysis Indicates Multiple Origins of Chloroplast Glyceraldehyde-3-Phosphate Dehydrogenase Genes in Dinoflagellates. Mol. Biol. Evol. 19: 1203-1207
Chudnovsky, Y., Li, J., Rizzo, P., Hastings, J. W. and Fagan, T. F. (2002) Cloning, Expression, and Characterization of a Histone-Like Protein from the Marine Dinoflagellate Lingulodinium polyedrum (Dinophyceae). J. Phycology 38: 543-550
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