Browse
Submit Data
Databases
API
Help

Dataset Information

16 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

The Arg-293 of Cryptochrome1 is responsible for the allosteric regulation of CLOCK-CRY1 binding in circadian rhythm.

ABSTRACT: Mammalian circadian clocks are driven by transcription/translation feedback loops composed of positive transcriptional activators (BMAL1 and CLOCK) and negative repressors (CRYPTOCHROMEs (CRYs) and PERIODs (PERs)). CRYs, in complex with PERs, bind to the BMAL1/CLOCK complex and repress E-box-driven transcription of clock-associated genes. There are two individual CRYs, with CRY1 exhibiting higher affinity to the BMAL1/CLOCK complex than CRY2. It is known that this differential binding is regulated by a dynamic serine-rich loop adjacent to the secondary pocket of both CRYs, but the underlying features controlling loop dynamics are not known. Here we report that allosteric regulation of the serine-rich loop is mediated by Arg-293 of CRY1, identified as a rare CRY1 SNP in the Ensembl and 1000 Genomes databases. The p.Arg293His CRY1 variant caused a shortened circadian period in a Cry1 ^-/- Cry2 ^-/- double knockout mouse embryonic fibroblast cell line. Moreover, the variant displayed reduced repressor activity on BMAL1/CLOCK driven transcription, which is explained by reduced affinity to BMAL1/CLOCK in the absence of PER2 compared with CRY1. Molecular dynamics simulations revealed that the p.Arg293His CRY1 variant altered a communication pathway between Arg-293 and the serine loop by reducing its dynamicity. Collectively, this study provides direct evidence that allosterism in CRY1 is critical for the regulation of circadian rhythm.

SUBMITTER: Gul S

PROVIDER: S-EPMC7863883 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

CRY1-CBS binding regulates circadian clock function and metabolism.

Project description:Circadian disruption influences metabolic health. Metabolism modulates circadian function. However, the mechanisms coupling circadian rhythms and metabolism remain poorly understood. Here, we report that cystathionine β-synthase (CBS), a central enzyme in one-carbon metabolism, functionally interacts with the core circadian protein cryptochrome 1 (CRY1). In cells, CBS augments CRY1-mediated repression of the CLOCK/BMAL1 complex and shortens circadian period. Notably, we find that mutant CBS-I278T protein, the most common cause of homocystinuria, does not bind CRY1 or regulate its repressor activity. Transgenic CbsZn/Zn mice, while maintaining circadian locomotor activity period, exhibit reduced circadian power and increased expression of E-BOX outputs. CBS function is reciprocally influenced by CRY1 binding. CRY1 modulates enzymatic activity of the CBS. Liver extracts from Cry1-/- mice show reduced CBS activity that normalizes after the addition of exogenous wild-type (WT) CRY1. Metabolomic analysis of WT, CbsZn/Zn , Cry1-/- , and Cry2-/- samples highlights the metabolic importance of endogenous CRY1. We observed temporal variation in one-carbon and transsulfuration pathways attributable to CRY1-induced CBS activation. CBS-CRY1 binding provides a post-translational switch to modulate cellular circadian physiology and metabolic control.

| S-EPMC7648728 | biostudies-literature

Nitrogen regulates CRY1 phosphorylation and circadian clock input pathways.

Project description:The delayed flowering phenotype caused by nitrogen (N) fertilizer application has been known for a long time, but we know little about the specific molecular mechanism for this phenomenon before. Our study indicated that low nitrogen increases the NADPH/NADP(+) and ATP/AMP ratios which affect adenosine monophosphate-activated protein kinase (AMPK) activity and phosphorylation and abundance of nuclear CRY1 protein. Then CRY1 acts in the N signal input pathway to the circadian clock. Here we further discuss: (1) the role of C/N ratio in flowering, (2) circadian oscillation of plant AMPK transcripts and proteins, (3) conservation of nutrition-mediated CRY1 phosphorylation and degradation, and (4) crosstalks between nitrogen signals and nitric oxide (NO) signals in flowering.

| S-EPMC5155457 | biostudies-other

Circadian rhythm in clock mutants

Project description:One hundred ninety wildtype male C57BL/6J mice age 7-10 weeks were purchased from Jackson Laboratory and entrained to a 12:12 light:dark cycle for 2 weeks. Mice were placed in light-tight boxes on a 12:12 LD cycle for 4 weeks, then released into constant darkness. Starting 30 hours after entry into DD (CT18), tissues from 5 (skeletal muscle) or 10 (liver or SCN) wildtype mice were collected every 4 hours for 48 hours, for a total of 12 timepoints. At timepoints 34 through 58 hours in DD, tissues from age-matched male C57BL/6J Clock/Clock homozygous mutant mice that had been treated with the same light entrainment protocol as the wildtype were collected. Tissues were collected from 5 Clock/Clock mutants at each timepoint except for 34 and 46 hours after the onset of DD, when tissues from 10 Clock/Clock mice were collected and run as independent replicates. Mice were sacrificed by cervical dislocation, and the optic nerves were severed in complete darkness; brain dissection was performed using illumination from an infrared viewer (FJW Industries, Palatine, IL). SCNs were dissected out, pooled at a density of 5 per tube in 100 ul RNAlater (Ambion, Austin, TX), frozen on dry ice, and stored at â80 degrees C until use. Keywords: SuperSeries This reference Series links data in the following related Series: GSE3746 Circadian skeletal muscle_wt and Clock mutants GSE3748 Circadian liver_wt and Clock mutants

2010-06-12 | E-GEOD-3751 | biostudies-arrayexpress

A MAGEL2-deubiquitinase complex modulates the ubiquitination of circadian rhythm protein CRY1.

Project description:MAGEL2 encodes the L2 member of the MAGE (melanoma antigen) protein family. Protein truncating mutations in MAGEL2 cause Schaaf-Yang syndrome, and MAGEL2 is one of a small set of genes deleted in Prader-Willi syndrome. Excessive daytime sleepiness, night-time or early morning waking, and narcoleptic symptoms are seen in people with Prader-Willi syndrome and Schaaf-Yang syndrome, while mice carrying a gene-targeted Magel2 deletion have disrupted circadian rhythms. These phenotypes suggest that MAGEL2 is important for the robustness of the circadian rhythm. However, a cellular role for MAGEL2 has yet to be elucidated. MAGEL2 influences the ubiquitination of substrate proteins to target them for further modification or to alter their stability through proteasomal degradation pathways. Here, we characterized relationships among MAGEL2 and proteins that regulate circadian rhythm. The effect of MAGEL2 on the key circadian rhythm protein cryptochrome 1 (CRY1) was assessed using in vivo proximity labelling (BioID), immunofluorescence microscopy and ubiquitination assays. We demonstrate that MAGEL2 modulates the ubiquitination of CRY1. Further studies will clarify the cellular role MAGEL2 normally plays in circadian rhythm, in part through ubiquitination and regulation of stability of the CRY1 protein.

| S-EPMC7173924 | biostudies-literature

Circadian rhythm in clock mutants

Project description:One hundred ninety wildtype male C57BL/6J mice age 7-10 weeks were purchased from Jackson Laboratory and entrained to a 12:12 light:dark cycle for 2 weeks. Mice were placed in light-tight boxes on a 12:12 LD cycle for 4 weeks, then released into constant darkness. Starting 30 hours after entry into DD (CT18), tissues from 5 (skeletal muscle) or 10 (liver or SCN) wildtype mice were collected every 4 hours for 48 hours, for a total of 12 timepoints. At timepoints 34 through 58 hours in DD, tissues from age-matched male C57BL/6J Clock/Clock homozygous mutant mice that had been treated with the same light entrainment protocol as the wildtype were collected. Tissues were collected from 5 Clock/Clock mutants at each timepoint except for 34 and 46 hours after the onset of DD, when tissues from 10 Clock/Clock mice were collected and run as independent replicates. Mice were sacrificed by cervical dislocation, and the optic nerves were severed in complete darkness; brain dissection was performed using illumination from an infrared viewer (FJW Industries, Palatine, IL). SCNs were dissected out, pooled at a density of 5 per tube in 100 ul RNAlater (Ambion, Austin, TX), frozen on dry ice, and stored at –80 degrees C until use. This SuperSeries is composed of the SubSeries listed below.

2007-02-07 | GSE3751 | GEO

DNA damage shifts circadian clock time via Hausp-dependent Cry1 stabilization.

Project description:The circadian transcriptional repressors cryptochrome 1 (Cry1) and 2 (Cry2) evolved from photolyases, bacterial light-activated DNA repair enzymes. In this study, we report that while they have lost DNA repair activity, Cry1/2 adapted to protect genomic integrity by responding to DNA damage through posttranslational modification and coordinating the downstream transcriptional response. We demonstrate that genotoxic stress stimulates Cry1 phosphorylation and its deubiquitination by Herpes virus associated ubiquitin-specific protease (Hausp, a.k.a Usp7), stabilizing Cry1 and shifting circadian clock time. DNA damage also increases Cry2 interaction with Fbxl3, destabilizing Cry2. Thus, genotoxic stress increases the Cry1/Cry2 ratio, suggesting distinct functions for Cry1 and Cry2 following DNA damage. Indeed, the transcriptional response to genotoxic stress is enhanced in Cry1-/- and blunted in Cry2-/- cells. Furthermore, Cry2-/- cells accumulate damaged DNA. These results suggest that Cry1 and Cry2, which evolved from DNA repair enzymes, protect genomic integrity via coordinated transcriptional regulation.

| S-EPMC4352707 | biostudies-literature

A CLOCK-binding small molecule disrupts the interaction between CLOCK and BMAL1 and enhances circadian rhythm amplitude.

Project description:Proper function of many physiological processes requires a robust circadian clock. Disruptions of the circadian clock can result in metabolic diseases, mood disorders, and accelerated aging. Therefore, identifying small molecules that specifically modulate regulatory core clock proteins may potentially enable better management of these disorders. In this study, we applied a structure-based molecular-docking approach to find small molecules that specifically bind to the core circadian regulator, the transcription factor circadian locomotor output cycles kaput (CLOCK). We identified 100 candidate molecules by virtual screening of ?2 million small molecules for those predicted to bind closely to the interface in CLOCK that interacts with its transcriptional co-regulator, Brain and muscle Arnt-like protein-1 (BMAL1). Using a mammalian two-hybrid system, real-time monitoring of circadian rhythm in U2OS cells, and various biochemical assays, we tested these compounds experimentally and found one, named CLK8, that specifically bound to and interfered with CLOCK activity. We show that CLK8 disrupts the interaction between CLOCK and BMAL1 and interferes with nuclear translocation of CLOCK both in vivo and in vitro Results from further experiments indicated that CLK8 enhances the amplitude of the cellular circadian rhythm by stabilizing the negative arm of the transcription/translation feedback loop without affecting period length. Our results reveal CLK8 as a tool for further studies of CLOCK's role in circadian rhythm amplitude regulation and as a potential candidate for therapeutic development to manage disorders associated with dampened circadian rhythms.

| S-EPMC7076206 | biostudies-literature

The Circadian Clock Protein CRY1 Is a Negative Regulator of HIF-1α.

Project description:The circadian clock and the hypoxia-signaling pathway are regulated by an integrated interplay of positive and negative feedback limbs that incorporate energy homeostasis and carcinogenesis. We show that the negative circadian regulator CRY1 is also a negative regulator of hypoxia-inducible factor (HIF). Mechanistically, CRY1 interacts with the basic-helix-loop-helix domain of HIF-1α via its tail region. Subsequently, CRY1 reduces HIF-1α half-life and binding of HIFs to target gene promoters. This appeared to be CRY1 specific because genetic disruption of CRY1, but not CRY2, affected the hypoxia response. Furthermore, CRY1 deficiency could induce cellular HIF levels, proliferation, and migration, which could be reversed by CRISPR/Cas9- or short hairpin RNA-mediated HIF knockout. Altogether, our study provides a mechanistic explanation for genetic association studies linking a disruption of the circadian clock with hypoxia-associated processes such as carcinogenesis.

| S-EPMC6416729 | biostudies-literature

Circadian rhythm of clock genes in human adipose explants.

Project description:To analyze in severely obese women the circadian expression of the clock genes hPer2, hBmal1, and hCry1 in explants from subcutaneous (SAT) and visceral (VAT) adipose tissue (AT), in order to elucidate whether this circadian clockwork can oscillate accurately and independently of the suprachiasmatic nucleus (SCN) and if glucocorticoid metabolism-related genes such as glucocorticoid receptor (hGr) and 11beta-hydroxysteroid dehydrogenase 1 (h11 beta Hsd1) and the transcription factor peroxisome proliferator activated receptor gamma (hPPAR gamma) are part of the clock controlled genes. AT biopsies were obtained from morbid obese patients (BMI > or =40 kg/m(2)) (n = 7). Anthropometric variables were measured and fasting plasma lipids and lipoprotein concentrations were analyzed. In order to carry out rhythmic expression analysis, AT explants were cultured during 24 h and gene expression was performed at the following times (T): 0, 6, 12, and 18 h, with quantitative real-time PCR. Clock genes oscillated accurately and independently of the SCN in AT explants. Their intrinsic oscillatory mechanism regulated the timing of other genes such as hPPAR gamma and glucocorticoid-related genes. Circadian patterns differed between VAT and SAT. Correlation analyses between the genetic circadian oscillation and components of the metabolic syndrome (MetS) revealed that subjects with a higher sagittal diameter showed an increased circadian variability in hPer2 expression (r = 0.91; P = 0.031) and hBmal1 (r = 0.90; P = 0.040). Data demonstrate the presence of peripheral circadian oscillators in human AT independently of the central circadian control mechanism. This knowledge paves the way for a better understanding of the circadian contribution to medical conditions such as obesity and MetS.

| S-EPMC4429875 | biostudies-literature