The role of the circadian clock in photoperiodism of the bean bugRiptortus pedestris

2021 ◽

Vol 22 (7) ◽

pp. 3787

Author(s):

Hussam Ibrahim ◽

Philipp Reus ◽

Anna Katharina Mundorf ◽

Anna-Lena Grothoff ◽

Valerie Rudenko ◽

...

Keyword(s):

Circadian Clock ◽

Transcriptional Repression ◽

Small Gtpase ◽

Main Role ◽

Interacting Proteins ◽

Casein Kinase 1 ◽

Bona Fide ◽

Kinetics Of

Repressor protein period (PER) complexes play a central role in the molecular oscillator mechanism of the mammalian circadian clock. While the main role of nuclear PER complexes is transcriptional repression, much less is known about the functions of cytoplasmic PER complexes. We found with a biochemical screen for PER2-interacting proteins that the small GTPase regulator GTPase-activating protein and VPS9 domain-containing protein 1 (GAPVD1), which has been identified previously as a component of cytoplasmic PER complexes in mice, is also a bona fide component of human PER complexes. We show that in situ GAPVD1 is closely associated with casein kinase 1 delta (CSNK1D), a kinase that regulates PER2 levels through a phosphoswitch mechanism, and that CSNK1D regulates the phosphorylation of GAPVD1. Moreover, phosphorylation determines the kinetics of GAPVD1 degradation and is controlled by PER2 and a C-terminal autoinhibitory domain in CSNK1D, indicating that the regulation of GAPVD1 phosphorylation is a novel function of cytoplasmic PER complexes and might be part of the oscillator mechanism or an output function of the circadian clock.

Download Full-text

Circadian clock protein Rev-erbα regulates neuroinflammation

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1812405116 ◽

2019 ◽

Vol 116 (11) ◽

pp. 5102-5107 ◽

Cited By ~ 36

Author(s):

Percy Griffin ◽

Julie M. Dimitry ◽

Patrick W. Sheehan ◽

Brian V. Lananna ◽

Chun Guo ◽

...

Keyword(s):

Circadian Clock ◽

Microglial Activation ◽

Time Of Day ◽

Resting State Functional Connectivity ◽

Promoter Regions ◽

Clock Component ◽

Glial Cultures ◽

Inflammatory Phenotype

Circadian dysfunction is a common attribute of many neurodegenerative diseases, most of which are associated with neuroinflammation. Circadian rhythm dysfunction has been associated with inflammation in the periphery, but the role of the core clock in neuroinflammation remains poorly understood. Here we demonstrate that Rev-erbα, a nuclear receptor and circadian clock component, is a mediator of microglial activation and neuroinflammation. We observed time-of-day oscillation in microglial immunoreactivity in the hippocampus, which was disrupted in Rev-erbα−/− mice. Rev-erbα deletion caused spontaneous microglial activation in the hippocampus and increased expression of proinflammatory transcripts, as well as secondary astrogliosis. Transcriptomic analysis of hippocampus from Rev-erbα−/− mice revealed a predominant inflammatory phenotype and suggested dysregulated NF-κB signaling. Primary Rev-erbα−/− microglia exhibited proinflammatory phenotypes and increased basal NF-κB activation. Chromatin immunoprecipitation revealed that Rev-erbα physically interacts with the promoter regions of several NF-κB–related genes in primary microglia. Loss of Rev-erbα in primary astrocytes had no effect on basal activation but did potentiate the inflammatory response to lipopolysaccharide (LPS). In vivo, Rev-erbα−/− mice exhibited enhanced hippocampal neuroinflammatory responses to peripheral LPS injection, while pharmacologic activation of Rev-erbs with the small molecule agonist SR9009 suppressed LPS-induced hippocampal neuroinflammation. Rev-erbα deletion influenced neuronal health, as conditioned media from Rev-erbα–deficient primary glial cultures exacerbated oxidative damage in cultured neurons. Rev-erbα−/− mice also exhibited significantly altered cortical resting-state functional connectivity, similar to that observed in neurodegenerative models. Our results reveal Rev-erbα as a pharmacologically accessible link between the circadian clock and neuroinflammation.

Download Full-text

Evidence for a dysfunction and disease-promoting role of the circadian clock in the diabetic retina

Experimental Eye Research ◽

10.1016/j.exer.2021.108751 ◽

2021 ◽

Vol 211 ◽

pp. 108751

Author(s):

Patrick Vancura ◽

Laura Oebel ◽

Simon Spohn ◽

Ute Frederiksen ◽

Kristina Schäfer ◽

...

Keyword(s):

Circadian Clock ◽

Diabetic Retina

Download Full-text

PHYSIOLOGICAL ROLE OF CIRCADIAN CLOCK GENE ON THE ENERGETIC METABOLISM IN HORSES

Journal of Veterinary Behavior ◽

10.1016/j.jveb.2021.10.002 ◽

2021 ◽

Author(s):

C. Giannetto ◽

F. Fazio ◽

E. Giudice ◽

G. Mazzullo ◽

G. Piccione

Keyword(s):

Circadian Clock ◽

Clock Gene ◽

Physiological Role ◽

Energetic Metabolism ◽

Circadian Clock Gene

Download Full-text

In Vivo Role of Phosphorylation of Cryptochrome 2 in the Mouse Circadian Clock

Molecular and Cellular Biology ◽

10.1128/mcb.00711-14 ◽

2014 ◽

Vol 34 (24) ◽

pp. 4464-4473 ◽

Cited By ~ 12

Author(s):

A. Hirano ◽

N. Kurabayashi ◽

T. Nakagawa ◽

G. Shioi ◽

T. Todo ◽

...

Keyword(s):

Circadian Clock ◽

Cryptochrome 2

Download Full-text

Circadian Clock Regulates Inflammation and the Development of Neurodegeneration

Frontiers in Cellular and Infection Microbiology ◽

10.3389/fcimb.2021.696554 ◽

2021 ◽

Vol 11 ◽

Author(s):

Xiao-Lan Wang ◽

Lianjian Li

Keyword(s):

Circadian Clock ◽

Immune Cells ◽

Brain Function ◽

Cellular Tissue ◽

Physiological Processes ◽

Circadian Control ◽

Prevention And Treatment ◽

Potential Strategy ◽

Peripheral Immune Cells

The circadian clock regulates numerous key physiological processes and maintains cellular, tissue, and systemic homeostasis. Disruption of circadian clock machinery influences key activities involved in immune response and brain function. Moreover, Immune activation has been closely linked to neurodegeneration. Here, we review the molecular clock machinery and the diurnal variation of immune activity. We summarize the circadian control of immunity in both central and peripheral immune cells, as well as the circadian regulation of brain cells that are implicated in neurodegeneration. We explore the important role of systemic inflammation on neurodegeneration. The circadian clock modulates cellular metabolism, which could be a mechanism underlying circadian control. We also discuss the circadian interventions implicated in inflammation and neurodegeneration. Targeting circadian clocks could be a potential strategy for the prevention and treatment of inflammation and neurodegenerative diseases.

Download Full-text

EARLY FLOWERING 3 controls temperature responsiveness of the circadian clock

10.1101/2020.11.11.378307 ◽

2020 ◽

Author(s):

Zihao Zhu ◽

Marcel Quint ◽

Muhammad Usman Anwer

Keyword(s):

Circadian Clock ◽

Biological Rhythms ◽

Early Flowering ◽

Climate Change Scenarios ◽

Temperature Changes ◽

Physiological Processes ◽

Average Global Temperature ◽

Clock Component ◽

Rhythmic Growth

SummaryPredictable changes in light and temperature during a diurnal cycle are major entrainment cues that enable the circadian clock to generate internal biological rhythms that are synchronized with the external environment. With the average global temperature predicted to keep increasing, the intricate light-temperature coordination that is necessary for clock functionality is expected to be seriously affected. Hence, understanding how temperature signals are perceived by the circadian clock has become an important issue, especially in light of climate change scenarios. In Arabidopsis, the clock component EARLY FLOWERING 3 (ELF3) not only serves as an essential light Zeitnehmer, but also functions as a thermosensor participating in thermomorphogenesis. However, the role of ELF3 in temperature entrainment of the circadian clock is not fully understood. Here, we report that ELF3 is essential for delivering temperature input to the clock. We demonstrate that in the absence of ELF3, the oscillator was unable to properly respond to temperature changes, resulting in an impaired gating of thermoresponses. Consequently, clock-controlled physiological processes such as rhythmic growth and cotyledon movement were disturbed. Together, our results reveal that ELF3 is an essential Zeitnehmer for temperature sensing of the oscillator, and thereby for coordinating the rhythmic control of thermoresponsive physiological outputs.

Download Full-text