Virtually all eukaryotic organisms appropriately examined have been shown to possess the capacity for endogenous temporal control and organization known as a circadian rhythm. The cellular machinery responsible for generating rhythms is collectively known as the biological clock. A healthy circadian clock underlies both physical and mental health. Because of the ubiquity of its influence on human mental and physiological processes - from circadian changes in basic human physiology to the clear involvement of rhythms in work/rest cycles and sleep - understanding the clock is basic to prevention and treatment of many physical and mental illnesses, from metabolic disorders to sleep/wake dysfunction and cancer. Our research has used genetic and molecular studies of the model eukaryote Neurospora to further our understanding of the organization of the circadian oscillator. Planned research lies within four foci. Focus #1 builds upon our understanding of the interplay between structure and function in core clock components. New data are inconsistent with some existing models and predicted roles for clock proteins. We will identify updated roles, interactions, and structures, as well as probing how clock-controlled phosphorylation guides essential interactions and activities of clock components. Focus #2 is centered on a deeper look at the role of phosphorylation in temperature compensation and the kinases that bring this about. Focus #3 builds upon our strong grounding in genetics and genomics as well as ongoing work that has identified three novel genes whose mutation alters period length by as much 18 hours. Examination of the bases of these effects will take us into aspects metabolism and gene expression heretofore unexplored in terms of circadian biology. Focus #4 explores completely new territory, pioneering the use of cell biological tools to complement genetics, exploring the regulatory plasticity of architecture of the circadian oscillator, and as time allows probing a novel genetic system that generates a circadian rhythm despite the absence of canonical clock components. Our long term goals are to describe, in the language of genetics and biochemistry, the feedback cycle comprising the circadian clock, how this cycle is synchronized with the environment, and how time information generated by the feedback cycle is used to regulate the behavior of cells and organisms. These projects are complementary and mutually enriching in that they rely on genetic and molecular techniques to dissect, and ultimately to understand, the organization of cells as a function of time.

Public Health Relevance

Biological clocks work in all cells of the human body to regulate metabolism. By studying cells of a fungus, as well as cells of mice and humans, we can understand how clock control works, how jet lag happens, and how clock malfunction leads to diseases like diabetes and mental illness.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Unknown (R35)
Project #
5R35GM118021-05
Application #
9937814
Study Section
Special Emphasis Panel (ZGM1)
Program Officer
Sesma, Michael A
Project Start
2016-06-01
Project End
2021-05-31
Budget Start
2020-06-01
Budget End
2021-05-31
Support Year
5
Fiscal Year
2020
Total Cost
Indirect Cost
Name
Dartmouth College
Department
Other Basic Sciences
Type
Schools of Medicine
DUNS #
041027822
City
Hanover
State
NH
Country
United States
Zip Code
03755
Fuller, Kevin K; Dunlap, Jay C; Loros, Jennifer J (2018) Light-regulated promoters for tunable, temporal, and affordable control of fungal gene expression. Appl Microbiol Biotechnol 102:3849-3863
Wang, Zheng; Wang, Junrui; Li, Ning et al. (2018) Light sensing by opsins and fungal ecology: NOP-1 modulates entry into sexual reproduction in response to environmental cues. Mol Ecol 27:216-232
Chen, Shan; Fuller, Kevin K; Dunlap, Jay C et al. (2018) Circadian Clearance of a Fungal Pathogen from the Lung Is Not Based on Cell-intrinsic Macrophage Rhythms. J Biol Rhythms 33:99-105
Zhou, Xiaoying; Wang, Bin; Emerson, Jillian M et al. (2018) A HAD family phosphatase CSP-6 regulates the circadian output pathway in Neurospora crassa. PLoS Genet 14:e1007192
Dunlap, Jay C; Loros, Jennifer J (2018) Just-So Stories and Origin Myths: Phosphorylation and Structural Disorder in Circadian Clock Proteins. Mol Cell 69:165-168
Ivanov, Ivaylo P; Wei, Jiajie; Caster, Stephen Z et al. (2017) Translation Initiation from Conserved Non-AUG Codons Provides Additional Layers of Regulation and Coding Capacity. MBio 8:
Dekhang, Rigzin; Wu, Cheng; Smith, Kristina M et al. (2017) The Neurospora Transcription Factor ADV-1 Transduces Light Signals and Temporal Information to Control Rhythmic Expression of Genes Involved in Cell Fusion. G3 (Bethesda) 7:129-142
Hughes, Michael E; Abruzzi, Katherine C; Allada, Ravi et al. (2017) Guidelines for Genome-Scale Analysis of Biological Rhythms. J Biol Rhythms 32:380-393
Dunlap, Jay C; Loros, Jennifer J (2017) Making Time: Conservation of Biological Clocks from Fungi to Animals. Microbiol Spectr 5:
Olivares-YaƱez, Consuelo; Emerson, Jillian; Kettenbach, Arminja et al. (2016) Modulation of Circadian Gene Expression and Metabolic Compensation by the RCO-1 Corepressor of Neurospora crassa. Genetics 204:163-76

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