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 specific aims are designed to further our understanding of the means through which this clock that regulates cell behavior is organized.
Specific Aim #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 time-of-day-specific clock-controlled phosphorylation guides essential interactions and activities of clock components.
Specific Aim#2 re-examines the overarching regulatory architecture of the eukaryotic circadian oscillator in light of new data that challenge a major precept of current theory, the essential role of protein turnover. This also prompts a closer look at the role of phosphorylation in temperature compensation and the kinases that bring this about.
Specific Aim #3 builds upon our strong grounding in genetics and genomics as well as ongoing work that has identified previously unstudied 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. 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 mice and humans, as well as cells of a fungus, 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
Research Project (R01)
Project #
5R01GM034985-28
Application #
8529546
Study Section
Special Emphasis Panel (ZRG1-CB-R (02))
Program Officer
Sesma, Michael A
Project Start
1986-02-01
Project End
2016-06-30
Budget Start
2013-07-01
Budget End
2014-06-30
Support Year
28
Fiscal Year
2013
Total Cost
$709,432
Indirect Cost
$271,511
Name
Dartmouth College
Department
Genetics
Type
Schools of Medicine
DUNS #
041027822
City
Hanover
State
NH
Country
United States
Zip Code
03755
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
Olivares-Yañez, 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
Hurley, Jennifer M; Loros, Jennifer J; Dunlap, Jay C (2016) Circadian Oscillators: Around the Transcription-Translation Feedback Loop and on to Output. Trends Biochem Sci 41:834-846
Conrad, Karen S; Hurley, Jennifer M; Widom, Joanne et al. (2016) Structure of the frequency-interacting RNA helicase: a protein interaction hub for the circadian clock. EMBO J 35:1707-19
Fuller, K K; Dunlap, J C; Loros, J J (2016) Fungal Light Sensing at the Bench and Beyond. Adv Genet 96:1-51
Wang, Zheng; Li, Ning; Li, Jigang et al. (2016) The Fast-Evolving phy-2 Gene Modulates Sexual Development in Response to Light in the Model Fungus Neurospora crassa. MBio 7:e02148
Wang, Bin; Zhou, Xiaoying; Loros, Jennifer J et al. (2016) Alternative Use of DNA Binding Domains by the Neurospora White Collar Complex Dictates Circadian Regulation and Light Responses. Mol Cell Biol 36:781-93
Dunlap, Jay C; Loros, Jennifer J (2016) Yes, circadian rhythms actually do affect almost everything. Cell Res 26:759-60
Hurley, Jennifer M; Loros, Jennifer J; Dunlap, Jay C (2016) The circadian system as an organizer of metabolism. Fungal Genet Biol 90:39-43
Fuller, Kevin K; Cramer, Robert A; Zegans, Michael E et al. (2016) Aspergillus fumigatus Photobiology Illuminates the Marked Heterogeneity between Isolates. MBio 7:

Showing the most recent 10 out of 96 publications