J. Woodland Hastings

Paul C. Mangelsdorf Professor of Natural Sciences

Department of Molecular and Cellular Biology
16 Divinity Avenue
Cambridge MA 02138-2020

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 polyedra (new name, Lingulodinium polyedrum), 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 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 and is part of a hairpin-loop structure.

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 and other dinoflagellates, the cellular localization and control of the light emitting organelles, and the luciferase genes. 

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For more information about circadian rhythms, try the NSF Center for Biological Timing.

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CURRICULUM VITAE

JOHN WOODLAND HASTINGS

Paul C. Mangelsdorf Professor of Natural Sciences
Dept. of Molecular & Biology
Harvard University, 16 Divinity Avenue
Cambridge, MA  01238
617/495-3714; fax 495-9300
email: hastings@fas.harvard.edu

14 Concord Ave.
Cambridge, MA  01238
617/492-8374
hastings@fas.harvard.edu

EDUCATION

PROFESSIONAL POSITIONS

PROFESSIONAL ACTIVITIES

AFFILIATIONS

HONORS

RESEARCH

BIOLUMINESCENCE, namely the ability to emit light, has originated and evolved independently many times in many different organisms; the different systems are thus biochemically distinct and have many diverse functions. My research is concerned with the fundamental biochemical mechanisms whereby chemical energy in such systems is converted to light energy, the biological functions of bioluminescence, and the genetic control of the synthesis and expression of such systems. The current research of my laboratory is concerned with cloning of genes associated with the luminescence systems in two groups of organisms, the marine dinoflagellates and larvae of diptera from New Zealand and the Appalacian mountains. We are studying the organization of the genes, and the regulation of the synthesis and expression of the luminescence systems.

CIRCADIAN (daily) CONTROL represents a very fundamental yet still very poorly understood feature of higher organisms. Jet lag is a symptom of the disruption of our circadian system. Indeed, all eukaryotic organisms--and even individual unicells and some prokaryotes--possess a temporal control mechanism involving many biochemical and physiological processes. Our research is concerned with the basic molecular and cellular mechanisms responsible for these rhythms--the biological clock. Current studies are focused on the circadian regulation of gene expression in the bioluminescent dinoflagellate Gonyaulax polyedra (now called Lingulodinium polyedrum). Genes whose products are clock controlled have been cloned in order to study the regulatory mechanisms involved. The role of protein phosphorylation in the circadian cycle is also under study.

PUBLICATIONS

Coeditor of three books and about 400 full length publications in professional journals. A complete list of publications is available. 

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Harvard University Biological Laboratories
16 Divinity Ave.
Cambridge, MA  02138
hastings@fas.harvard.edu