Hasting Lab Home PageMy research is concerned with the molecular components that participate in and regulate the circadian cycle, the so called Òbiological clockÓ, 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 3Õ 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.
Selected Publications:
Fagan, Thomas, Hastings, J. Woodland and Morse, David. (1998). The phylogeny of glyceraldehyde-3-phosphate dehydrogenase indicates lateral gene transfer from cryptomonads to dinoflagellates. J. Mol. Evolution 47:633-639.
Wilson, T. and Hastings, J.W. (1998). Bioluminescence Annu. Rev. Cell Devel. Biol. 14:197-230.
Hastings, J. W. and Morin, J. G. (1998). Photons for reporting molecular events: Green fluorescent protein and four luciferase systems. pp. 17-41 in Green Fluorescent Protein: Properties, applications and protocols. (Martin Chalfie and Steven Kain, Eds.) Wiley-Liss, N.Y.
Comolli, James and Hastings (1999). J. W. Novel Effects on The Gonyaulax
Circadian System Produced by the Protein Kinase Inhibitor Staurosporine.
J. Biol. Rhythms 14:10-18.