A period without PER: understanding 24-hour rhythms without classic transcription and translation feedback loops

Millius, Arthur; Ode, Koji L.; Ueda, Hiroki R.

doi:10.12688/f1000research.18158.1

Cited by 13 publications

(4 citation statements)

References 102 publications

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“…Interestingly, the concept of the eukaryotic post‐translational clock mechanism we propose is not new (Roenneberg & Merrow, 1998; Merrow et al , 2006; Qin et al , 2010; Jolley et al , 2012) and resembles the KaiA/B/C mechanism elucidated in cyanobacteria (Nakajima et al , 2005; Teng et al , 2013). The challenge will now be to identify additional factors that, in concert with CK1 and GSK3, and protein phosphatase 1 (Lee et al , 2011), serve as the functional equivalents of KaiA/B/C, allowing reconstitution of the mammalian circadian clock in vitro (Nakajima et al , 2005; Millius et al , 2019).…”

Section: Discussionmentioning

confidence: 99%

CRYPTOCHROMES confer robustness, not rhythmicity, to circadian timekeeping

et al. 2021

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Circadian rhythms are a pervasive property of mammalian cells, tissues and behaviour, ensuring physiological adaptation to solar time. Models of cellular timekeeping revolve around transcriptional feedback repression, whereby CLOCK and BMAL1 activate the expression of PERIOD (PER) and CRYPTOCHROME (CRY), which in turn repress CLOCK/BMAL1 activity. CRY proteins are therefore considered essential components of the cellular clock mechanism, supported by behavioural arrhythmicity of CRY-deficient (CKO) mice under constant conditions. Challenging this interpretation, we find locomotor rhythms in adult CKO mice under specific environmental conditions and circadian rhythms in cellular PER2 levels when CRY is absent. CRY-less oscillations are variable in their expression and have shorter periods than wild-type controls. Importantly, we find classic circadian hallmarks such as temperature compensation and period determination by CK1δ/ϵ activity to be maintained. In the absence of CRY-mediated feedback repression and rhythmic Per2 transcription, PER2 protein rhythms are sustained for several cycles, accompanied by circadian variation in protein stability. We suggest that, whereas circadian transcriptional feedback imparts robustness and functionality onto biological clocks, the core timekeeping mechanism is post-translational.

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Section: Discussionmentioning

confidence: 99%

CRYPTOCHROMES confer robustness, not rhythmicity, to circadian timekeeping

et al. 2021

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“…Центральный циркадианный осциллятор, или «водитель» эндогенных ритмов, находится в супрахиазматическом ядре гипоталамуса и представлен комплексом нейронов, содержащих часовые гены (clock-genes proteins), обеспечивая синтез белков, которые поддерживают околосуточную ритмику большинства функций [43,44]. Супрахиазматическое ядро определяет циркадианный ритм эпифиза и выработку мелатонина -одного из основных участников регуляции суточного цикла.…”

Section: спонтанная гибернацияunclassified

Mechanisms of low-temperature rehabilitation technologies. Natural and artificial hypothermia

Shevelev,

Petrova,

Mengistu

et al. 2023

Physical and rehabilitation medicine, medical rehabilitation

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The literature review covers an analysis of the typical protective and adaptive reaction mechanisms that develop in small rodents that spontaneously hibernate under the cold snap, together with warm-blooded animals and humans during circadian fall of the body temperature at night time and in a course of a slow-wave sleep, along with induced artificial therapeutic hypothermia. The general features of neuroprotection states development in natural endogenous and induced hypothermia are highlighted, which include metabolic, epigenetic and biophysical reactions that ensure the formation of nonspecific tolerance of the brain to potentially damaging effects. Significant attention has been devoted to the participation of hibernation proteins, opioids and antioxidant systems in the processes of safe exit from state of torpor in animals and in implementation of sleep restoration functions. Taking into account the circadian nature formation of endogenous brains hypothermia at night and in the phases of slow sleep, it is suggested that periodic temperature exposure on the cerebral cortex can be applied in order to restore the disturbed circadian rhythms. From the standpoint of common mechanisms of endogenous and induced hypothermia, selective hypothermia of the cerebral cortex can be considered as a nature-like technology. Based on the extensive experimental material indicating a significant neuroprotective potentials of low temperatures during hibernation, diurnal hypothermia as well as artificially induced hypothermia, it was stated that implementation of the technology for selective hypothermia of the cerebral cortex in order to prevent the negative consequences of cerebral catastrophes are a perspective trend.

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“…Strong conservation of the operating modes is observed between insects and mammals, including at the level of the molecular actors ( Tomioka and Matsumoto, 2015 ; Figure 10 ). It is worth mentioning that post-transcriptional regulation and protein modification, such as phosphorylation and oxidation, have been hypothesized as alternatives ways to building a ticking clock ( Millius et al, 2019 ).…”

Section: Orientation In Time: the Circadian Clocksmentioning

confidence: 99%

Exposure to Artificial Light at Night and the Consequences for Flora, Fauna, and Ecosystems

et al. 2020

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The present review draws together wide-ranging studies performed over the last decades that catalogue the effects of artificial-light-at-night (ALAN) upon living species and their environment. We provide an overview of the tremendous variety of light-detection strategies which have evolved in living organisms - unicellular, plants and animals, covering chloroplasts (plants), and the plethora of ocular and extra-ocular organs (animals). We describe the visual pigments which permit photo-detection, paying attention to their spectral characteristics, which extend from the ultraviolet into infrared. We discuss how organisms use light information in a way crucial for their development, growth and survival: phototropism, phototaxis, photoperiodism, and synchronization of circadian clocks. These aspects are treated in depth, as their perturbation underlies much of the disruptive effects of ALAN. The review goes into detail on circadian networks in living organisms, since these fundamental features are of critical importance in regulating the interface between environment and body. Especially, hormonal synthesis and secretion are often under circadian and circannual control, hence perturbation of the clock will lead to hormonal imbalance. The review addresses how the ubiquitous introduction of light-emitting diode technology may exacerbate, or in some cases reduce, the generalized ever-increasing light pollution. Numerous examples are given of how widespread exposure to ALAN is perturbing many aspects of plant and animal behaviour and survival: foraging, orientation, migration, seasonal reproduction, colonization and more. We examine the potential problems at the level of individual species and populations and extend the debate to the consequences for ecosystems. We stress, through a few examples, the synergistic harmful effects resulting from the impacts of ALAN combined with other anthropogenic pressures, which often impact the neuroendocrine loops in vertebrates. The article concludes by debating how these anthropogenic changes could be mitigated by more reasonable use of available technology – for example by restricting illumination to more essential areas and hours, directing lighting to avoid wasteful radiation and selecting spectral emissions, to reduce impact on circadian clocks. We end by discussing how society should take into account the potentially major consequences that ALAN has on the natural world and the repercussions for ongoing human health and welfare.

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A period without PER: understanding 24-hour rhythms without classic transcription and translation feedback loops

Cited by 13 publications

References 102 publications

CRYPTOCHROMES confer robustness, not rhythmicity, to circadian timekeeping

CRYPTOCHROMES confer robustness, not rhythmicity, to circadian timekeeping

Mechanisms of low-temperature rehabilitation technologies. Natural and artificial hypothermia

Exposure to Artificial Light at Night and the Consequences for Flora, Fauna, and Ecosystems

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