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Köbler C, Schmelling NM, Wiegard A, Pawlowski A, Pattanayak GK, Spät P, Scheurer NM, Sebastian KN, Stirba FP, Berwanger LC, Kolkhof P, Maček B, Rust MJ, Axmann IM, Wilde A. Two KaiABC systems control circadian oscillations in one cyanobacterium. Nat Commun 2024; 15:7674. [PMID: 39227593 PMCID: PMC11372060 DOI: 10.1038/s41467-024-51914-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Accepted: 08/20/2024] [Indexed: 09/05/2024] Open
Abstract
The circadian clock of cyanobacteria, which predicts daily environmental changes, typically includes a standard oscillator consisting of proteins KaiA, KaiB, and KaiC. However, several cyanobacteria have diverse Kai protein homologs of unclear function. In particular, Synechocystis sp. PCC 6803 harbours, in addition to a canonical kaiABC gene cluster (named kaiAB1C1), two further kaiB and kaiC homologs (kaiB2, kaiB3, kaiC2, kaiC3). Here, we identify a chimeric KaiA homolog, named KaiA3, encoded by a gene located upstream of kaiB3. At the N-terminus, KaiA3 is similar to response-regulator receiver domains, whereas its C-terminal domain resembles that of KaiA. Homology analysis shows that a KaiA3-KaiB3-KaiC3 system exists in several cyanobacteria and other bacteria. Using the Synechocystis sp. PCC 6803 homologs, we observe circadian oscillations in KaiC3 phosphorylation in vitro in the presence of KaiA3 and KaiB3. Mutations of kaiA3 affect KaiC3 phosphorylation, leading to growth defects under both mixotrophic and chemoheterotrophic conditions. KaiC1 and KaiC3 exhibit phase-locked free-running phosphorylation rhythms. Deletion of either system (∆kaiAB1C1 or ∆kaiA3B3C3) alters the period of the cellular backscattering rhythm. Furthermore, both oscillators are required to maintain high-amplitude, self-sustained backscatter oscillations with a period of approximately 24 h, indicating their interconnected nature.
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Affiliation(s)
- Christin Köbler
- Institute of Biology III, Faculty of Biology, University of Freiburg, 79104, Freiburg, Germany
| | - Nicolas M Schmelling
- Institute for Synthetic Microbiology, Biology Department, Heinrich Heine University Düsseldorf, 40225, Düsseldorf, Germany
| | - Anika Wiegard
- Institute for Synthetic Microbiology, Biology Department, Heinrich Heine University Düsseldorf, 40225, Düsseldorf, Germany
| | - Alice Pawlowski
- Institute for Synthetic Microbiology, Biology Department, Heinrich Heine University Düsseldorf, 40225, Düsseldorf, Germany
| | - Gopal K Pattanayak
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, IL, 60637, USA
| | - Philipp Spät
- Department of Quantitative Proteomics, Interfaculty Institute for Cell Biology, Eberhard Karls University Tübingen, 72076, Tübingen, Germany
| | - Nina M Scheurer
- Institute of Biology III, Faculty of Biology, University of Freiburg, 79104, Freiburg, Germany
| | - Kim N Sebastian
- Institute of Biology III, Faculty of Biology, University of Freiburg, 79104, Freiburg, Germany
| | - Florian P Stirba
- Institute for Synthetic Microbiology, Biology Department, Heinrich Heine University Düsseldorf, 40225, Düsseldorf, Germany
| | - Lutz C Berwanger
- Institute for Synthetic Microbiology, Biology Department, Heinrich Heine University Düsseldorf, 40225, Düsseldorf, Germany
| | - Petra Kolkhof
- Institute for Synthetic Microbiology, Biology Department, Heinrich Heine University Düsseldorf, 40225, Düsseldorf, Germany
| | - Boris Maček
- Department of Quantitative Proteomics, Interfaculty Institute for Cell Biology, Eberhard Karls University Tübingen, 72076, Tübingen, Germany
| | - Michael J Rust
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, IL, 60637, USA
| | - Ilka M Axmann
- Institute for Synthetic Microbiology, Biology Department, Heinrich Heine University Düsseldorf, 40225, Düsseldorf, Germany.
| | - Annegret Wilde
- Institute of Biology III, Faculty of Biology, University of Freiburg, 79104, Freiburg, Germany.
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2
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Santos-Merino M, Sakkos JK, Singh AK, Ducat DC. Coordination of carbon partitioning and photosynthesis by a two-component signaling network in Synechococcus elongatus PCC 7942. Metab Eng 2024; 81:38-52. [PMID: 37925065 DOI: 10.1016/j.ymben.2023.11.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 10/26/2023] [Accepted: 11/02/2023] [Indexed: 11/06/2023]
Abstract
Photosynthetic organisms need to balance the rate of photosynthesis with the utilization of photosynthetic products by downstream reactions. While such "source/sink" pathways are well-interrogated in plants, analogous regulatory systems are unknown or poorly studied in single-celled algal and cyanobacterial species. Towards the identification of energy/sugar sensors in cyanobacteria, we utilized an engineered strain of Synechococcus elongatus PCC 7942 that allows experimental manipulation of carbon status. We conducted a screening of all two-component systems (TCS) and serine/threonine kinases (STKs) encoded in S. elongatus PCC 7942 by analyzing phenotypes consistent with sucrose-induced relaxation of sink inhibition. We narrowed the candidate sensor proteins by analyzing changes observed after sucrose feeding. We show that a clustered TCS network containing RpaA, CikB, ManS and NblS are involved in the regulation of genes related to photosynthesis, pigment synthesis, and Rubisco concentration in response to sucrose. Altogether, these results highlight a regulatory TCS group that may play under-appreciated functions in carbon partitioning and energy balancing in cyanobacteria.
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Affiliation(s)
- María Santos-Merino
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, United States
| | - Jonathan K Sakkos
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, United States
| | - Amit K Singh
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, United States
| | - Daniel C Ducat
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, United States; Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, 48824, United States.
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3
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Siebieszuk A, Sejbuk M, Witkowska AM. Studying the Human Microbiota: Advances in Understanding the Fundamentals, Origin, and Evolution of Biological Timekeeping. Int J Mol Sci 2023; 24:16169. [PMID: 38003359 PMCID: PMC10671191 DOI: 10.3390/ijms242216169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Revised: 11/07/2023] [Accepted: 11/08/2023] [Indexed: 11/26/2023] Open
Abstract
The recently observed circadian oscillations of the intestinal microbiota underscore the profound nature of the human-microbiome relationship and its importance for health. Together with the discovery of circadian clocks in non-photosynthetic gut bacteria and circadian rhythms in anucleated cells, these findings have indicated the possibility that virtually all microorganisms may possess functional biological clocks. However, they have also raised many essential questions concerning the fundamentals of biological timekeeping, its evolution, and its origin. This narrative review provides a comprehensive overview of the recent literature in molecular chronobiology, aiming to bring together the latest evidence on the structure and mechanisms driving microbial biological clocks while pointing to potential applications of this knowledge in medicine. Moreover, it discusses the latest hypotheses regarding the evolution of timing mechanisms and describes the functions of peroxiredoxins in cells and their contribution to the cellular clockwork. The diversity of biological clocks among various human-associated microorganisms and the role of transcriptional and post-translational timekeeping mechanisms are also addressed. Finally, recent evidence on metabolic oscillators and host-microbiome communication is presented.
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Affiliation(s)
- Adam Siebieszuk
- Department of Physiology, Faculty of Medicine, Medical University of Bialystok, Mickiewicza 2C, 15-222 Białystok, Poland;
| | - Monika Sejbuk
- Department of Food Biotechnology, Faculty of Health Sciences, Medical University of Bialystok, Szpitalna 37, 15-295 Białystok, Poland;
| | - Anna Maria Witkowska
- Department of Food Biotechnology, Faculty of Health Sciences, Medical University of Bialystok, Szpitalna 37, 15-295 Białystok, Poland;
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Wollmuth EM, Angert ER. Microbial circadian clocks: host-microbe interplay in diel cycles. BMC Microbiol 2023; 23:124. [PMID: 37161348 PMCID: PMC10173096 DOI: 10.1186/s12866-023-02839-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Accepted: 03/28/2023] [Indexed: 05/11/2023] Open
Abstract
BACKGROUND Circadian rhythms, observed across all domains of life, enable organisms to anticipate and prepare for diel changes in environmental conditions. In bacteria, a circadian clock mechanism has only been characterized in cyanobacteria to date. These clocks regulate cyclical patterns of gene expression and metabolism which contribute to the success of cyanobacteria in their natural environments. The potential impact of self-generated circadian rhythms in other bacterial and microbial populations has motivated extensive research to identify novel circadian clocks. MAIN TEXT Daily oscillations in microbial community composition and function have been observed in ocean ecosystems and in symbioses. These oscillations are influenced by abiotic factors such as light and the availability of nutrients. In the ocean ecosystems and in some marine symbioses, oscillations are largely controlled by light-dark cycles. In gut systems, the influx of nutrients after host feeding drastically alters the composition and function of the gut microbiota. Conversely, the gut microbiota can influence the host circadian rhythm by a variety of mechanisms including through interacting with the host immune system. The intricate and complex relationship between the microbiota and their host makes it challenging to disentangle host behaviors from bacterial circadian rhythms and clock mechanisms that might govern the daily oscillations observed in these microbial populations. CONCLUSIONS While the ability to anticipate the cyclical behaviors of their host would likely be enhanced by a self-sustained circadian rhythm, more evidence and further studies are needed to confirm whether host-associated heterotrophic bacteria possess such systems. In addition, the mechanisms by which heterotrophic bacteria might respond to diel cycles in environmental conditions has yet to be uncovered.
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Affiliation(s)
- Emily M Wollmuth
- Department of Microbiology, Cornell University, 123 Wing Drive, Ithaca, NY, 14853, USA
| | - Esther R Angert
- Department of Microbiology, Cornell University, 123 Wing Drive, Ithaca, NY, 14853, USA.
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Larrondo LF. Circadian entrainment of in vitro reactions, in real time, and around the clock. Proc Natl Acad Sci U S A 2023; 120:e2303566120. [PMID: 37094142 PMCID: PMC10161006 DOI: 10.1073/pnas.2303566120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2023] Open
Affiliation(s)
- Luis F. Larrondo
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, 8331150Santiago, Chile
- Agencia Nacional de Investigación y Desarrollo-Millennium Science Initiative Program, Millennium Institute for Integrative Biology, 7500565Santiago, Chile
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Fang M, Chavan AG, LiWang A, Golden SS. Synchronization of the circadian clock to the environment tracked in real time. Proc Natl Acad Sci U S A 2023; 120:e2221453120. [PMID: 36940340 PMCID: PMC10068778 DOI: 10.1073/pnas.2221453120] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Accepted: 02/08/2023] [Indexed: 03/22/2023] Open
Abstract
The circadian system of the cyanobacterium Synechococcus elongatus PCC 7942 relies on a three-protein nanomachine (KaiA, KaiB, and KaiC) that undergoes an oscillatory phosphorylation cycle with a period of ~24 h. This core oscillator can be reconstituted in vitro and is used to study the molecular mechanisms of circadian timekeeping and entrainment. Previous studies showed that two key metabolic changes that occur in cells during the transition into darkness, changes in the ATP/ADP ratio and redox status of the quinone pool, are cues that entrain the circadian clock. By changing the ATP/ADP ratio or adding oxidized quinone, one can shift the phase of the phosphorylation cycle of the core oscillator in vitro. However, the in vitro oscillator cannot explain gene expression patterns because the simple mixture lacks the output components that connect the clock to genes. Recently, a high-throughput in vitro system termed the in vitro clock (IVC) that contains both the core oscillator and the output components was developed. Here, we used IVC reactions and performed massively parallel experiments to study entrainment, the synchronization of the clock with the environment, in the presence of output components. Our results indicate that the IVC better explains the in vivo clock-resetting phenotypes of wild-type and mutant strains and that the output components are deeply engaged with the core oscillator, affecting the way input signals entrain the core pacemaker. These findings blur the line between input and output pathways and support our previous demonstration that key output components are fundamental parts of the clock.
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Affiliation(s)
- Mingxu Fang
- Center for Circadian Biology, University of California, San Diego, La Jolla, CA92093
| | - Archana G. Chavan
- School of Natural Sciences, University of California, Merced, CA95343
| | - Andy LiWang
- Center for Circadian Biology, University of California, San Diego, La Jolla, CA92093
- School of Natural Sciences, University of California, Merced, CA95343
- Department of Chemistry & Biochemistry, University of California, Merced, CA95343
| | - Susan S. Golden
- Center for Circadian Biology, University of California, San Diego, La Jolla, CA92093
- Department of Molecular Biology, University of California, San Diego, La Jolla, CA92093
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7
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Milner PT, Zhang Z, Herde ZD, Vedire NR, Zhang F, Realff MJ, Wilson CJ. Performance Prediction of Fundamental Transcriptional Programs. ACS Synth Biol 2023; 12:1094-1108. [PMID: 36935615 PMCID: PMC10127286 DOI: 10.1021/acssynbio.2c00593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/21/2023]
Abstract
Transcriptional programming leverages systems of engineered transcription factors to impart decision-making (e.g., Boolean logic) in chassis cells. The number of components used to construct said decision-making systems is rapidly increasing, making an exhaustive experimental evaluation of iterations of biological circuits impractical. Accordingly, we posited that a predictive tool is needed to guide and accelerate the design of transcriptional programs. The work described here involves the development and experimental characterization of a large collection of network-capable single-INPUT logical operations─i.e., engineered BUFFER (repressor) and engineered NOT (antirepressor) logical operations. Using this single-INPUT data and developed metrology, we were able to model and predict the performances of all fundamental two-INPUT compressed logical operations (i.e., compressed AND gates and compressed NOR gates). In addition, we were able to model and predict the performance of compressed mixed phenotype logical operations (A NIMPLY B gates and complementary B NIMPLY A gates). These results demonstrate that single-INPUT data is sufficient to accurately predict both the qualitative and quantitative performance of a complex circuit. Accordingly, this work has set the stage for the predictive design of transcriptional programs of greater complexity.
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Affiliation(s)
- Prasaad T Milner
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-2000, United States
| | - Ziqiao Zhang
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-2000, United States
| | - Zachary D Herde
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-2000, United States
| | - Namratha R Vedire
- School of Computer Science, Georgia Institute of Technology, Atlanta, Georgia 30332-2000, United States
| | - Fumin Zhang
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-2000, United States
| | - Matthew J Realff
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-2000, United States
| | - Corey J Wilson
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-2000, United States
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8
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Bishé B, Golden SS, Golden JW. Glycogen metabolism is required for optimal cyanobacterial growth in the rapid light-dark cycle of low-Earth orbit. LIFE SCIENCES IN SPACE RESEARCH 2023; 36:18-26. [PMID: 36682825 PMCID: PMC9989776 DOI: 10.1016/j.lssr.2022.11.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 10/10/2022] [Accepted: 11/01/2022] [Indexed: 06/17/2023]
Abstract
Some designs for bioregenerative life support systems to enable human space missions incorporate cyanobacteria for removal of carbon dioxide, generation of oxygen, and treatment of wastewater, as well as providing a source of nutrition. In this study, we examined the effects of the short light-dark (LD) cycle of low-Earth orbit on algal and cyanobacterial growth, approximating conditions on the International Space Station, which orbits Earth roughly every 90 min. We found that growth of green algae was similar in both normal 12 h light:12 h dark (12 h:12 h LD) and 45':45' LD cycles. Three diverse strains of cyanobacteria were not only capable of growth in short 45':45' LD cycles, but actually grew better than in 12 h:12 h LD cycles. We showed that 45':45' LD cycles do not affect the endogenous 24 h circadian rhythms of Synechococcus elongatus. Using a dense library of randomly barcoded transposon mutants, we identified genes whose loss is detrimental for the growth of S. elongatus under 45':45' LD cycles. These include several genes involved in glycogen metabolism and the oxidative pentose phosphate pathway. Notably, 45':45' LD cycles did not affect the fitness of strains that carry mutations in the biological circadian oscillator or the clock input and output regulatory pathways. Overall, this study shows that cultures of cyanobacteria could be grown under natural sunlight of low-Earth orbit and highlights the utility of a functional genomic study in a model organism to better understand key biological processes in conditions that are relevant to space travel.
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Affiliation(s)
- Bryan Bishé
- Department of Molecular Biology, University of California San Diego, 92093 La Jolla, CA, United States
| | - Susan S Golden
- Department of Molecular Biology, University of California San Diego, 92093 La Jolla, CA, United States
| | - James W Golden
- Department of Molecular Biology, University of California San Diego, 92093 La Jolla, CA, United States.
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Wei X, Huang Z, Jiang L, Li Y, Zhang X, Leng Y, Jiang C. Charting the landscape of the environmental exposome. IMETA 2022; 1:e50. [PMID: 38867899 PMCID: PMC10989948 DOI: 10.1002/imt2.50] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 07/13/2022] [Accepted: 07/30/2022] [Indexed: 06/14/2024]
Abstract
The exposome depicts the total exposures in the lifetime of an organism. Human exposome comprises exposures from environmental and humanistic sources. Biological, chemical, and physical environmental exposures pose potential health threats, especially to susceptible populations. Although still in its nascent stage, we are beginning to recognize the vast and dynamic nature of the exposome. In this review, we systematically summarize the biological and chemical environmental exposomes in three broad environmental matrices-air, soil, and water; each contains several distinct subcategories, along with a brief introduction to the physical exposome. Disease-related environmental exposures are highlighted, and humans are also a major source of disease-related biological exposures. We further discuss the interactions between biological, chemical, and physical exposomes. Finally, we propose a list of outstanding challenges under the exposome research framework that need to be addressed to move the field forward. Taken together, we present a detailed landscape of environmental exposome to prime researchers to join this exciting new field.
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Affiliation(s)
- Xin Wei
- Zhejiang Provincial Key Laboratory of Cancer Molecular Cell Biology, Life Sciences InstituteZhejiang UniversityHangzhouZhejiangChina
| | - Zinuo Huang
- Zhejiang Provincial Key Laboratory of Cancer Molecular Cell Biology, Life Sciences InstituteZhejiang UniversityHangzhouZhejiangChina
| | - Liuyiqi Jiang
- Zhejiang Provincial Key Laboratory of Cancer Molecular Cell Biology, Life Sciences InstituteZhejiang UniversityHangzhouZhejiangChina
| | - Yueer Li
- Zhejiang Provincial Key Laboratory of Cancer Molecular Cell Biology, Life Sciences InstituteZhejiang UniversityHangzhouZhejiangChina
| | - Xinyue Zhang
- Department of GeneticsStanford UniversityStanfordCaliforniaUSA
| | - Yuxin Leng
- Department of Intensive Care UnitPeking University Third HospitalBeijingChina
| | - Chao Jiang
- Zhejiang Provincial Key Laboratory of Cancer Molecular Cell Biology, Life Sciences InstituteZhejiang UniversityHangzhouZhejiangChina
- Zhejiang Provincial Key Laboratory of Pancreatic Disease, First Affiliated HospitalZhejiang University School of MedicineHangzhouZhejiangChina
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10
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Muñoz-Marín MDC, Duhamel S, Björkman KM, Magasin JD, Díez J, Karl DM, García-Fernández JM. Differential Timing for Glucose Assimilation in Prochlorococcus and Coexistent Microbial Populations in the North Pacific Subtropical Gyre. Microbiol Spectr 2022; 10:e0246622. [PMID: 36098532 PMCID: PMC9602893 DOI: 10.1128/spectrum.02466-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Accepted: 08/22/2022] [Indexed: 01/04/2023] Open
Abstract
The marine cyanobacterium Prochlorococcus can utilize glucose as a source of carbon. However, the relative importance of inorganic and organic carbon assimilation and the timing of glucose assimilation are still poorly understood in these numerically dominant cyanobacteria. Here, we investigated whole microbial community and group-specific primary production and glucose assimilation using incubations with radioisotopes combined with flow cytometry cell sorting. We also studied changes in the microbial community structure in response to glucose enrichments and analyzed the transcription of Prochlorocccus genes involved in carbon metabolism and photosynthesis. Our results showed a diel variation for glucose assimilation in Prochlorococcus, with maximum assimilation at midday and minimum at midnight (~2-fold change), which was different from that of the total microbial community. This suggests that the timing in glucose assimilation in Prochlorococcus is coupled to photosynthetic light reactions producing energy, it being more convenient for Prochlorococcus to show maximum glucose uptake precisely when the rest of microbial populations have their minimum glucose uptake. Many transcriptional responses to glucose enrichment occurred after 12- and 24-h periods, but community composition did not change. High-light Prochlorococcus strains were the most impacted by glucose addition, with transcript-level increases observed for genes in pathways for glucose metabolism, such as the pentose phosphate pathway, the Entner-Doudoroff pathway, glycolysis, respiration, and glucose transport. While Prochlorococcus C assimilation from glucose represented less than 0.1% of the bacterium's photosynthetic C fixation, increased assimilation during the day and glcH gene upregulation upon glucose enrichment indicate an important role of mixotrophic C assimilation by natural populations of Prochlorococcus. IMPORTANCE Several studies have demonstrated that Prochlorococcus, the most abundant photosynthetic organism on Earth, can assimilate organic molecules, such as amino acids, amino sugars, ATP, phosphonates, and dimethylsulfoniopropionate. This autotroph can also assimilate small amounts of glucose, supporting the hypothesis that Prochlorococcus is mixotrophic. Our results show, for the first time, a diel variability in glucose assimilation by natural populations of Prochlorococcus with maximum assimilation during midday. Based on our previous results, this indicates that Prochlorococcus could maximize glucose uptake by using ATP made during the light reactions of photosynthesis. Furthermore, Prochlorococcus showed a different timing of glucose assimilation from the total population, which may offer considerable fitness advantages over competitors "temporal niches." Finally, we observed transcriptional changes in some of the genes involved in carbon metabolism, suggesting that Prochlorococcus can use both pathways previously proposed in cyanobacteria to metabolize glucose.
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Affiliation(s)
- María del Carmen Muñoz-Marín
- Departamento de Bioquímica y Biología Molecular, Campus de Excelencia Internacional Agroalimentario, Universidad de Córdoba, Córdoba, Spain
| | - Solange Duhamel
- Lamont-Doherty Earth Observatory of Columbia University, Division of Biology and Paleo Environment, Palisades, New York, USA
| | - Karin M. Björkman
- Daniel K. Inouye Center for Microbial Oceanography: Research and Education (C-MORE), University of Hawaii at Manoa, C-MORE Hale, Honolulu, Hawaii, USA
| | - Jonathan D. Magasin
- Ocean Sciences Department, University of California, Santa Cruz, California, USA
| | - Jesús Díez
- Departamento de Bioquímica y Biología Molecular, Campus de Excelencia Internacional Agroalimentario, Universidad de Córdoba, Córdoba, Spain
| | - David M. Karl
- Daniel K. Inouye Center for Microbial Oceanography: Research and Education (C-MORE), University of Hawaii at Manoa, C-MORE Hale, Honolulu, Hawaii, USA
| | - José M. García-Fernández
- Departamento de Bioquímica y Biología Molecular, Campus de Excelencia Internacional Agroalimentario, Universidad de Córdoba, Córdoba, Spain
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11
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Choi H, Rao MC, Chang EB. Gut microbiota as a transducer of dietary cues to regulate host circadian rhythms and metabolism. Nat Rev Gastroenterol Hepatol 2021; 18:679-689. [PMID: 34002082 PMCID: PMC8521648 DOI: 10.1038/s41575-021-00452-2] [Citation(s) in RCA: 73] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/08/2021] [Indexed: 02/06/2023]
Abstract
Certain members of the gut microbiota exhibit diurnal variations in relative abundance and function to serve as non-canonical drivers of host circadian rhythms and metabolism. Also known as microbial oscillators, these microorganisms entrain upon non-photic cues, primarily dietary, to modulate host metabolism by providing input to both circadian clock-dependent and clock-independent host networks. Microbial oscillators are generally promoted by plant-based, low-fat (lean) diets, and most are abolished by low-fibre, high-sugar, high-fat (Western) diets. The changes in microbial oscillators under different diets then affect host metabolism by altering central and peripheral host circadian clock functions and/or by directly affecting other metabolic targets. Here, we review the unique role of the gut microbiota as a non-photic regulator of host circadian rhythms and metabolism. We describe genetic, environmental, dietary and other host factors such as sex and gut immunity that determine the composition and behaviour of microbial oscillators. The mechanisms by which these oscillators regulate host circadian gene expression and metabolic state are further discussed. Because of the gut microbiota's unique role as a non-photic driver of host metabolism and circadian rhythms, the development and clinical application of novel gut microbiota-related diagnostics and therapeutics hold great promise for achieving and maintaining metabolic health.
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Affiliation(s)
- Hyoann Choi
- Department of Medicine, Knapp Center for Biomedical Discovery, Chicago, IL, USA.,Department of Biological Engineering and The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Mrinalini C. Rao
- Department of Physiology & Biophysics, University of Illinois at Chicago, Chicago, IL, USA
| | - Eugene B. Chang
- Department of Medicine, Knapp Center for Biomedical Discovery, Chicago, IL, USA.,
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12
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Abstract
Disruption of circadian rhythms causes decreased health and fitness, and evidence from multiple organisms links clock disruption to dysregulation of the cell cycle. However, the function of circadian regulation for the essential process of DNA replication remains elusive. Here, we demonstrate that in the cyanobacterium Synechococcus elongatus, a model organism with the simplest known circadian oscillator, the clock generates rhythms in DNA replication to minimize the number of open replication forks near dusk that would have to complete after sunset. Metabolic rhythms generated by the clock ensure that resources are available early at night to support any remaining replication forks. Combining mathematical modeling and experiments, we show that metabolic defects caused by clock-environment misalignment result in premature replisome disassembly and replicative abortion in the dark, leaving cells with incomplete chromosomes that persist through the night. Our study thus demonstrates that a major function of this ancient clock in cyanobacteria is to ensure successful completion of genome replication in a cycling environment.
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13
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Landa M, Turk-Kubo KA, Cornejo-Castillo FM, Henke BA, Zehr JP. Critical Role of Light in the Growth and Activity of the Marine N 2-Fixing UCYN-A Symbiosis. Front Microbiol 2021; 12:666739. [PMID: 34025621 PMCID: PMC8139342 DOI: 10.3389/fmicb.2021.666739] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 04/08/2021] [Indexed: 11/27/2022] Open
Abstract
The unicellular N2-fixing cyanobacteria UCYN-A live in symbiosis with haptophytes in the Braarudosphaera bigelowii lineage. Maintaining N2-fixing symbioses between two unicellular partners requires tight coordination of multiple biological processes including cell growth and division and, in the case of the UCYN-A symbiosis, N2 fixation of the symbiont and photosynthesis of the host. In this system, it is thought that the host photosynthesis supports the high energetic cost of N2 fixation, and both processes occur during the light period. However, information on this coordination is very limited and difficult to obtain because the UCYN-A symbiosis has yet to be available in culture. Natural populations containing the UCYN-A2 symbiosis were manipulated to explore the effects of alterations of regular light and dark periods and inhibition of host photosynthesis on N2 fixation (single cell N2 fixation rates), nifH gene transcription, and UCYN-A2 cell division (fluorescent in situ hybridization and nifH gene abundances). The results showed that the light period is critical for maintenance of regular patterns of gene expression, N2 fixation and symbiont replication and cell division. This study suggests a crucial role for the host as a producer of fixed carbon, rather than light itself, in the regulation and implementation of these cellular processes in UCYN-A.
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Affiliation(s)
- Marine Landa
- Ocean Sciences Department, University of California, Santa Cruz, Santa Cruz, CA, United States
| | - Kendra A Turk-Kubo
- Ocean Sciences Department, University of California, Santa Cruz, Santa Cruz, CA, United States
| | | | - Britt A Henke
- Ocean Sciences Department, University of California, Santa Cruz, Santa Cruz, CA, United States
| | - Jonathan P Zehr
- Ocean Sciences Department, University of California, Santa Cruz, Santa Cruz, CA, United States
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14
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Engineered systems of inducible anti-repressors for the next generation of biological programming. Nat Commun 2020; 11:4440. [PMID: 32895374 PMCID: PMC7477573 DOI: 10.1038/s41467-020-18302-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 08/07/2020] [Indexed: 01/14/2023] Open
Abstract
Traditionally engineered genetic circuits have almost exclusively used naturally occurring transcriptional repressors. Recently, non-natural transcription factors (repressors) have been engineered and employed in synthetic biology with great success. However, transcriptional anti-repressors have largely been absent with regard to the regulation of genes in engineered genetic circuits. Here, we present a workflow for engineering systems of non-natural anti-repressors. In this study, we create 41 inducible anti-repressors. This collection of transcription factors respond to two distinct ligands, fructose (anti-FruR) or D-ribose (anti-RbsR); and were complemented by 14 additional engineered anti-repressors that respond to the ligand isopropyl β-d-1-thiogalactopyranoside (anti-LacI). In turn, we use this collection of anti-repressors and complementary genetic architectures to confer logical control over gene expression. Here, we achieved all NOT oriented logical controls (i.e., NOT, NOR, NAND, and XNOR). The engineered transcription factors and corresponding series, parallel, and series-parallel genetic architectures represent a nascent anti-repressor based transcriptional programming structure. Transcriptional anti-repressors have been largely absent in the design of regulated genetic circuits. Here, the authors present a workflow of the engineering of non-natural anti-reperssors that can be built into NOT oriented logic gates.
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15
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Pattanayak GK, Liao Y, Wallace EWJ, Budnik B, Drummond DA, Rust MJ. Daily Cycles of Reversible Protein Condensation in Cyanobacteria. Cell Rep 2020; 32:108032. [PMID: 32814039 PMCID: PMC10005845 DOI: 10.1016/j.celrep.2020.108032] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 07/08/2020] [Accepted: 07/23/2020] [Indexed: 12/21/2022] Open
Abstract
An emerging principle of cell biology is the regulated conversion of macromolecules between soluble and condensed states. To screen for such regulation of the cyanobacterial proteome, we use quantitative mass spectrometry to identify proteins that change solubility during the day-night cycle. We find a set of night-insoluble proteins that includes many enzymes in essential metabolic pathways. Using time-lapse microscopy and isotope labeling, we show that these proteins reversibly transition between punctate structures at night and a soluble state during the day without substantial degradation. We find that the cyanobacterial circadian clock regulates the kinetics of puncta formation during the night and that the appearance of puncta indicates the metabolic status of the cell. Reversible condensation of specific enzymes is thus a regulated response to the day-night cycle and may reflect a general bacterial strategy used in fluctuating growth conditions.
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Affiliation(s)
- Gopal K Pattanayak
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60637, USA
| | - Yi Liao
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60637, USA
| | - Edward W J Wallace
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL 60637, USA
| | - Bogdan Budnik
- Mass Spectrometry and Proteomics Resource Laboratory, FAS Division of Science, Harvard University, Cambridge, MA 02138, USA
| | - D Allan Drummond
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL 60637, USA
| | - Michael J Rust
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60637, USA; Department of Physics, University of Chicago, Chicago, IL 60637, USA.
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16
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Malik DM, Paschos GK, Sehgal A, Weljie AM. Circadian and Sleep Metabolomics Across Species. J Mol Biol 2020; 432:3578-3610. [PMID: 32376454 PMCID: PMC7781158 DOI: 10.1016/j.jmb.2020.04.027] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 04/28/2020] [Accepted: 04/28/2020] [Indexed: 02/06/2023]
Abstract
Under normal circadian function, metabolic control is temporally coordinated across tissues and behaviors with a 24-h period. However, circadian disruption results in negative consequences for metabolic homeostasis including energy or redox imbalances. Yet, circadian disruption has become increasingly prevalent within today's society due to many factors including sleep loss. Metabolic consequences of both have been revealed by metabolomics analyses of circadian biology and sleep. Specifically, two primary analytical platforms, mass spectrometry and nuclear magnetic resonance spectroscopy, have been used to study molecular clock and sleep influences on overall metabolic rhythmicity. For example, human studies have demonstrated the prevalence of metabolic rhythms in human biology, as well as pan-metabolome consequences of sleep disruption. However, human studies are limited to peripheral metabolic readouts primarily through minimally invasive procedures. For further tissue- and organism-specific investigations, a number of model systems have been studied, based upon the conserved nature of both the molecular clock and sleep across species. Here we summarize human studies as well as key findings from metabolomics studies using mice, Drosophila, and zebrafish. While informative, a limitation in existing literature is a lack of interpretation regarding dynamic synthesis or catabolism within metabolite pools. To this extent, future work incorporating isotope tracers, specific metabolite reporters, and single-cell metabolomics may provide a means of exploring dynamic activity in pathways of interest.
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Affiliation(s)
- Dania M Malik
- Pharmacology Graduate Group, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Systems Pharmacology and Translational Therapeutics, University of Pennsylvania, Philadelphia, PA 19104, USA; Institute for Translational Medicine and Therapeutics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Georgios K Paschos
- Department of Systems Pharmacology and Translational Therapeutics, University of Pennsylvania, Philadelphia, PA 19104, USA; Institute for Translational Medicine and Therapeutics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Amita Sehgal
- Penn Chronobiology, University of Pennsylvania, Philadelphia, PA 19104, USA; Howard Hughes Medical Institute, Perelman School of Medicine, University of Pennsylvania, PA 19104, USA
| | - Aalim M Weljie
- Department of Systems Pharmacology and Translational Therapeutics, University of Pennsylvania, Philadelphia, PA 19104, USA; Institute for Translational Medicine and Therapeutics, University of Pennsylvania, Philadelphia, PA 19104, USA.
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17
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Xia P, Ling H, Foo JL, Chang MW. Synthetic Biology Toolkits for Metabolic Engineering of Cyanobacteria. Biotechnol J 2019; 14:e1800496. [DOI: 10.1002/biot.201800496] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 02/19/2019] [Indexed: 12/20/2022]
Affiliation(s)
- Peng‐Fei Xia
- Department of Biochemistry Yong Loo Lin School of MedicineNational University of Singapore8 Medical Drive Singapore 117597 Singapore
- NUS Synthetic Biology for Clinical and Technological Innovation (SynCTI)National University of Singapore28 Medical Drive Singapore 117456 Singapore
| | - Hua Ling
- Department of Biochemistry Yong Loo Lin School of MedicineNational University of Singapore8 Medical Drive Singapore 117597 Singapore
- NUS Synthetic Biology for Clinical and Technological Innovation (SynCTI)National University of Singapore28 Medical Drive Singapore 117456 Singapore
| | - Jee Loon Foo
- Department of Biochemistry Yong Loo Lin School of MedicineNational University of Singapore8 Medical Drive Singapore 117597 Singapore
- NUS Synthetic Biology for Clinical and Technological Innovation (SynCTI)National University of Singapore28 Medical Drive Singapore 117456 Singapore
| | - Matthew Wook Chang
- Department of Biochemistry Yong Loo Lin School of MedicineNational University of Singapore8 Medical Drive Singapore 117597 Singapore
- NUS Synthetic Biology for Clinical and Technological Innovation (SynCTI)National University of Singapore28 Medical Drive Singapore 117456 Singapore
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18
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Kelly LW, Nelson CE, Haas AF, Naliboff DS, Calhoun S, Carlson CA, Edwards RA, Fox MD, Hatay M, Johnson MD, Kelly ELA, Lim YW, Macherla S, Quinlan ZA, Silva GGZ, Vermeij MJA, Zgliczynski B, Sandin SA, Smith JE, Rohwer F. Diel population and functional synchrony of microbial communities on coral reefs. Nat Commun 2019; 10:1691. [PMID: 30979882 PMCID: PMC6461649 DOI: 10.1038/s41467-019-09419-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 02/28/2019] [Indexed: 12/28/2022] Open
Abstract
On coral reefs, microorganisms are essential for recycling nutrients to primary producers through the remineralization of benthic-derived organic matter. Diel investigations of reef processes are required to holistically understand the functional roles of microbial players in these ecosystems. Here we report a metagenomic analysis characterizing microbial communities in the water column overlying 16 remote forereef sites over a diel cycle. Our results show that microbial community composition is more dissimilar between day and night samples collected from the same site than between day or night samples collected across geographically distant reefs. Diel community differentiation is largely driven by the flux of Psychrobacter sp., which is two-orders of magnitude more abundant during the day. Nighttime communities are enriched with species of Roseobacter, Halomonas, and Alteromonas encoding a greater variety of pathways for carbohydrate catabolism, further illustrating temporal patterns of energetic provisioning between different marine microbes. Dynamic diel fluctuations of microbial populations could also support the efficient trophic transfer of energy posited in coral reef food webs.
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Affiliation(s)
- Linda Wegley Kelly
- Department of Biology, San Diego State University, San Diego, 92182, USA.
| | - Craig E Nelson
- Department of Oceanography and Sea Grant College Program, Center for Microbial Oceanography: Research and Education, University of Hawai'i at Mānoa, Honolulu, 96822, USA
| | - Andreas F Haas
- Department of Marine Microbiology and Biogeochemistry, NIOZ Royal Netherlands Institute for Sea Research and Utrecht University, Texel, The Netherlands
| | - Douglas S Naliboff
- Department of Biology, San Diego State University, San Diego, 92182, USA
| | - Sandi Calhoun
- Department of Biology, San Diego State University, San Diego, 92182, USA
| | - Craig A Carlson
- Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, 93106, USA
| | - Robert A Edwards
- Department of Biology, San Diego State University, San Diego, 92182, USA
| | - Michael D Fox
- Scripps Institution of Oceanography, University of California, San Diego, 92093, USA
| | - Mark Hatay
- Department of Biology, San Diego State University, San Diego, 92182, USA
| | - Maggie D Johnson
- Scripps Institution of Oceanography, University of California, San Diego, 92093, USA.,Smithsonian Marine Station, Ft. Pierce, FL, 34949, USA
| | - Emily L A Kelly
- Scripps Institution of Oceanography, University of California, San Diego, 92093, USA
| | - Yan Wei Lim
- Department of Biology, San Diego State University, San Diego, 92182, USA
| | | | - Zachary A Quinlan
- Department of Oceanography and Sea Grant College Program, Center for Microbial Oceanography: Research and Education, University of Hawai'i at Mānoa, Honolulu, 96822, USA
| | | | - Mark J A Vermeij
- Caribbean Marine Biological Institute (CARMABI), Willemstad, Curaçao.,Aquatic Microbiology, University of Amsterdam, Amsterdam, The Netherlands
| | - Brian Zgliczynski
- Scripps Institution of Oceanography, University of California, San Diego, 92093, USA
| | - Stuart A Sandin
- Scripps Institution of Oceanography, University of California, San Diego, 92093, USA
| | - Jennifer E Smith
- Scripps Institution of Oceanography, University of California, San Diego, 92093, USA
| | - Forest Rohwer
- Department of Biology, San Diego State University, San Diego, 92182, USA.,Viral Information Institute, San Diego State University, San Diego, 92182, USA
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19
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Kim SC, Nusinow DA, Sorkin ML, Pruneda-Paz J, Wang X. Interaction and Regulation Between Lipid Mediator Phosphatidic Acid and Circadian Clock Regulators. THE PLANT CELL 2019; 31:399-416. [PMID: 30674693 PMCID: PMC6447011 DOI: 10.1105/tpc.18.00675] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 12/07/2018] [Accepted: 01/22/2019] [Indexed: 05/06/2023]
Abstract
Circadian clocks play important roles in regulating cellular metabolism, but the reciprocal effect that metabolism has on the clock is largely unknown in plants. Here, we show that the central glycerolipid metabolite and lipid mediator phosphatidic acid (PA) interacts with and modulates the function of the core clock regulators LATE ELONGATED HYPOCOTYL (LHY) and CIRCADIAN CLOCK ASSOCIATED1 (CCA1) in Arabidopsis (Arabidopsis thaliana). PA reduced the ability of LHY and CCA1 to bind the promoter of their target gene TIMING OF CAB EXPRESSION1 Increased PA accumulation and inhibition of PA-producing enzymes had opposite effects on circadian clock outputs. Diurnal change in levels of several membrane phospholipid species, including PA, observed in wild type was lost in the LHY and CCA1 double knockout mutant. Storage lipid accumulation was also affected in the clock mutants. These results indicate that the interaction of PA with the clock regulator may function as a cellular conduit to integrate the circadian clock with lipid metabolism.
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Affiliation(s)
- Sang-Chul Kim
- Department of Biology, University of Missouri, St. Louis, Missouri 63121
- Donald Danforth Plant Science Center, St. Louis, Missouri 63132
| | | | - Maria L Sorkin
- Donald Danforth Plant Science Center, St. Louis, Missouri 63132
- Division of Biology and Biomedical Sciences, Washington University in St. Louis, St. Louis, Missouri 63110
| | - Jose Pruneda-Paz
- Section of Cell and Developmental Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, California 92093
| | - Xuemin Wang
- Department of Biology, University of Missouri, St. Louis, Missouri 63121
- Donald Danforth Plant Science Center, St. Louis, Missouri 63132
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20
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Monti M, Lubensky DK, Ten Wolde PR. Robustness of Clocks to Input Noise. PHYSICAL REVIEW LETTERS 2018; 121:078101. [PMID: 30169070 DOI: 10.1103/physrevlett.121.078101] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Revised: 03/30/2018] [Indexed: 06/08/2023]
Abstract
To estimate the time, many organisms, ranging from cyanobacteria to animals, employ a circadian clock which is based on a limit-cycle oscillator that can tick autonomously with a nearly 24 h period. Yet, a limit-cycle oscillator is not essential for knowing the time, as exemplified by bacteria that possess an "hourglass": a system that when forced by an oscillatory light input exhibits robust oscillations from which the organism can infer the time, but that in the absence of driving relaxes to a stable fixed point. Here, using models of the Kai system of cyanobacteria, we compare a limit-cycle oscillator with two hourglass models, one that without driving relaxes exponentially and one that does so in an oscillatory fashion. In the limit of low input noise, all three systems are equally informative on time, yet in the regime of high input-noise the limit-cycle oscillator is far superior. The same behavior is found in the Stuart-Landau model, indicating that our result is universal.
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Affiliation(s)
- Michele Monti
- FOM Institute AMOLF, Science Park 104, 1098 XE Amsterdam, Netherlands
| | - David K Lubensky
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109-1040, USA
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21
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Minow MAA, Ávila LM, Turner K, Ponzoni E, Mascheretti I, Dussault FM, Lukens L, Rossi V, Colasanti J. Distinct gene networks modulate floral induction of autonomous maize and photoperiod-dependent teosinte. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:2937-2952. [PMID: 29688423 PMCID: PMC5972621 DOI: 10.1093/jxb/ery110] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Accepted: 03/16/2018] [Indexed: 05/25/2023]
Abstract
Temperate maize was domesticated from its tropical ancestor, teosinte. Whereas temperate maize is an autonomous day-neutral plant, teosinte is an obligate short-day plant that requires uninterrupted long nights to induce flowering. Leaf-derived florigenic signals trigger reproductive growth in both teosinte and temperate maize. To study the genetic mechanisms underlying floral inductive pathways in maize and teosinte, mRNA and small RNA genome-wide expression analyses were conducted on leaf tissue from plants that were induced or not induced to flower. Transcriptome profiles reveal common differentially expressed genes during floral induction, but a comparison of candidate flowering time genes indicates that photoperiod and autonomous pathways act independently. Expression differences in teosinte are consistent with the current paradigm for photoperiod-induced flowering, where changes in circadian clock output trigger florigen production. Conversely, differentially expressed genes in temperate maize link carbon partitioning and flowering, but also show altered expression of circadian clock genes that are distinct from those altered upon photoperiodic induction in teosinte. Altered miRNA399 levels in both teosinte and maize suggest a novel common connection between flowering and phosphorus perception. These findings provide insights into the molecular mechanisms underlying a strengthened autonomous pathway that enabled maize growth throughout temperate regions.
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Affiliation(s)
- Mark A A Minow
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Luis M Ávila
- Plant Agriculture Department, University of Guelph, Guelph, Ontario, Canada
| | - Katie Turner
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Elena Ponzoni
- Council for Agricultural Research and Economics, Research Centre for Cereal and Industrial Crops, Bergamo, Italy
| | - Iride Mascheretti
- Council for Agricultural Research and Economics, Research Centre for Cereal and Industrial Crops, Bergamo, Italy
| | - Forest M Dussault
- Research and Development, Canadian Food Inspection Agency, Ottawa, Ontario, Canada
| | - Lewis Lukens
- Plant Agriculture Department, University of Guelph, Guelph, Ontario, Canada
| | - Vincenzo Rossi
- Council for Agricultural Research and Economics, Research Centre for Cereal and Industrial Crops, Bergamo, Italy
| | - Joseph Colasanti
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
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22
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Fei C, Cao Y, Ouyang Q, Tu Y. Design principles for enhancing phase sensitivity and suppressing phase fluctuations simultaneously in biochemical oscillatory systems. Nat Commun 2018; 9:1434. [PMID: 29651016 PMCID: PMC5897384 DOI: 10.1038/s41467-018-03826-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Accepted: 03/14/2018] [Indexed: 11/09/2022] Open
Abstract
Biological systems need to function accurately in the presence of strong noise and at the same time respond sensitively to subtle external cues. Here we study design principles in biochemical oscillatory circuits to achieve these two seemingly incompatible goals. We show that energy dissipation can enhance phase sensitivity linearly by driving the phase-amplitude coupling and increase timing accuracy by suppressing phase diffusion. Two general design principles in the key underlying reaction loop formed by two antiparallel pathways are found to optimize oscillation performance with a given energy budget: balancing the forward-to-backward flux ratio between the two pathways to reduce phase diffusion and maximizing the net flux of the phase-advancing pathway relative to that of the phase-retreating pathway to enhance phase sensitivity. Experimental evidences consistent with these design principles are found in the circadian clock of cyanobacteria. Future experiments to test the predicted dependence of phase sensitivity on energy dissipation are proposed.
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Affiliation(s)
- Chenyi Fei
- The State Key Laboratory for Artificial Microstructures and Mesoscopic Physics, School of Physics, Peking University, Beijing, 100871, China
| | - Yuansheng Cao
- Department of Physics, UC San Diego, La Jolla, CA, 92093, USA
| | - Qi Ouyang
- The State Key Laboratory for Artificial Microstructures and Mesoscopic Physics, School of Physics, Peking University, Beijing, 100871, China
| | - Yuhai Tu
- IBM T. J. Watson Research Center, Yorktown Heights, New York, NY, 10598, USA.
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23
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Espinosa J, Labella JI, Cantos R, Contreras A. Energy drives the dynamic localization of cyanobacterial nitrogen regulators during diurnal cycles. Environ Microbiol 2018; 20:1240-1252. [PMID: 29441670 DOI: 10.1111/1462-2920.14071] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Revised: 02/07/2018] [Accepted: 02/08/2018] [Indexed: 12/31/2022]
Abstract
Cyanobacteria, phototrophic organisms performing oxygenic photosynthesis, must adapt their metabolic processes to the challenges imposed by the succession of days and nights. Two conserved cyanobacterial proteins, PII and PipX, function as hubs of the nitrogen interaction network, forming complexes with a variety of diverse targets. While PII proteins are found in all three domains of life as integrators of signals of the nitrogen and carbon balance, PipX proteins are unique to cyanobacteria, where they provide a mechanistic link between PII signalling and the control of gene expression by the global nitrogen regulator NtcA. Here we demonstrate that PII and PipX display distinct localization patterns during diurnal cycles, co-localizing into the same foci at the periphery and poles of the cells during dark periods, a circadian-independent process requiring a low ATP/ADP ratio. Genetic, cellular biology and biochemical approaches used here provide new insights into the nitrogen regulatory network, calling attention to the roles of PII as energy sensors and its interactions with PipX in the context of essential signalling pathways. This study expands the contribution of the nitrogen regulators PII and PipX to integrate and transduce key environmental signals that allow cyanobacteria to thrive in our planet.
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Affiliation(s)
- Javier Espinosa
- Departamento de Fisiología, Genética y Microbiología, Universidad de Alicante, Alicante, Spain
| | - José I Labella
- Departamento de Fisiología, Genética y Microbiología, Universidad de Alicante, Alicante, Spain
| | - Raquel Cantos
- Departamento de Fisiología, Genética y Microbiología, Universidad de Alicante, Alicante, Spain
| | - Asunción Contreras
- Departamento de Fisiología, Genética y Microbiología, Universidad de Alicante, Alicante, Spain
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24
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Seki M, Ohara T, Hearn TJ, Frank A, da Silva VCH, Caldana C, Webb AAR, Satake A. Adjustment of the Arabidopsis circadian oscillator by sugar signalling dictates the regulation of starch metabolism. Sci Rep 2017; 7:8305. [PMID: 28814797 PMCID: PMC5559614 DOI: 10.1038/s41598-017-08325-y] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 07/20/2017] [Indexed: 02/02/2023] Open
Abstract
Arabidopsis plants store part of the carbon fixed by photosynthesis as starch to sustain growth at night. Two competing hypotheses have been proposed to explain this diel starch turnover based on either the measurement of starch abundance with respect to circadian time, or the sensing of sugars to feedback to the circadian oscillator to dynamically adjust the timing of starch turnover. We report a phase oscillator model that permitted derivation of the ideal responses of the circadian regulation of starch breakdown to maintain sucrose homeostasis. Testing the model predictions using a sugar-unresponsive mutant of Arabidopsis demonstrated that the dynamics of starch turnover arise from the circadian clock measuring and responding to the rate of change of cellular sucrose. Our theory and experiments suggest that starch turnover is controlled by the circadian clock acting as a dynamic homeostat responding to sucrose signals to maintain carbon homeostasis.
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Affiliation(s)
- Motohide Seki
- 0000 0001 2242 4849grid.177174.3Department of Biology, Faculty of Science, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395 Japan
| | - Takayuki Ohara
- 0000 0001 2242 4849grid.177174.3Department of Biology, Faculty of Science, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395 Japan ,0000 0001 2173 7691grid.39158.36Graduate School of Environmental Science, Hokkaido University, N10W5, Sapporo, 060-0810 Japan
| | - Timothy J. Hearn
- 0000000121885934grid.5335.0Department of Plant Sciences, University of Cambridge, Cambridge, CB2 3EA United Kingdom
| | - Alexander Frank
- 0000000121885934grid.5335.0Department of Plant Sciences, University of Cambridge, Cambridge, CB2 3EA United Kingdom
| | - Viviane C. H. da Silva
- Brazilian Bioethanol Science and Technology Laboratory (CTBE), Rua Giuseppe Máximo Scolfaro 10.000 CEP 13083-100 Campinas, São Paulo, Brazil
| | - Camila Caldana
- Brazilian Bioethanol Science and Technology Laboratory (CTBE), Rua Giuseppe Máximo Scolfaro 10.000 CEP 13083-100 Campinas, São Paulo, Brazil ,Max Planck Partner Group at Brazilian Bioethanol Science and Technology Laboratory, Campinas, SP Brazil
| | - Alex A. R. Webb
- 0000000121885934grid.5335.0Department of Plant Sciences, University of Cambridge, Cambridge, CB2 3EA United Kingdom
| | - Akiko Satake
- 0000 0001 2242 4849grid.177174.3Department of Biology, Faculty of Science, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395 Japan
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25
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Paijmans J, Lubensky DK, Ten Wolde PR. Period Robustness and Entrainability of the Kai System to Changing Nucleotide Concentrations. Biophys J 2017; 113:157-173. [PMID: 28700914 PMCID: PMC5510911 DOI: 10.1016/j.bpj.2017.05.048] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 05/01/2017] [Accepted: 05/30/2017] [Indexed: 10/19/2022] Open
Abstract
Circadian clocks must be able to entrain to time-varying signals to keep their oscillations in phase with the day-night rhythm. On the other hand, they must also exhibit input compensation: their period must remain approximately one day in different constant environments. The posttranslational oscillator of the Kai system can be entrained by transient or oscillatory changes in the ATP fraction, yet is insensitive to constant changes in this fraction. We study in three different models of this system how these two seemingly conflicting criteria are met. We find that one of these (our recently published Paijmans model) exhibits the best tradeoff between input compensation and entrainability: on the footing of equal phase-response curves, it exhibits the strongest input compensation. Performing stochastic simulations at the level of individual hexamers allows us to identify a new, to our knowledge, mechanism, which is employed by the Paijmans model to achieve input compensation: at lower ATP fraction, the individual hexamers make a shorter cycle in the phosphorylation state space, which compensates for the slower pace at which they traverse the cycle.
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Affiliation(s)
- Joris Paijmans
- AMOLF, Amsterdam, the Netherlands, University of Michigan, Ann Arbor, Michigan
| | - David K Lubensky
- Department of Physics, University of Michigan, Ann Arbor, Michigan
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26
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Leypunskiy E, Lin J, Yoo H, Lee U, Dinner AR, Rust MJ. The cyanobacterial circadian clock follows midday in vivo and in vitro. eLife 2017; 6:e23539. [PMID: 28686160 PMCID: PMC5605227 DOI: 10.7554/elife.23539] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Accepted: 07/06/2017] [Indexed: 01/20/2023] Open
Abstract
Circadian rhythms are biological oscillations that schedule daily changes in physiology. Outside the laboratory, circadian clocks do not generally free-run but are driven by daily cues whose timing varies with the seasons. The principles that determine how circadian clocks align to these external cycles are not well understood. Here, we report experimental platforms for driving the cyanobacterial circadian clock both in vivo and in vitro. We find that the phase of the circadian rhythm follows a simple scaling law in light-dark cycles, tracking midday across conditions with variable day length. The core biochemical oscillator comprised of the Kai proteins behaves similarly when driven by metabolic pulses in vitro, indicating that such dynamics are intrinsic to these proteins. We develop a general mathematical framework based on instantaneous transformation of the clock cycle by external cues, which successfully predicts clock behavior under many cycling environments.
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Affiliation(s)
- Eugene Leypunskiy
- Graduate Program in Biophysical Sciences, The University of Chicago, Chicago, United States
| | - Jenny Lin
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, United States
| | - Haneul Yoo
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, United States
| | - UnJin Lee
- Department of Ecology and Evolution, The University of Chicago, Chicago, United States
| | - Aaron R Dinner
- Graduate Program in Biophysical Sciences, The University of Chicago, Chicago, United States
- Department of Chemistry, The University of Chicago, Chicago, United States
- James Franck Institute, The University of Chicago, Chicago, United States
| | - Michael J Rust
- Graduate Program in Biophysical Sciences, The University of Chicago, Chicago, United States
- Department of Ecology and Evolution, The University of Chicago, Chicago, United States
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, United States
- Department of Physics, The University of Chicago, Chicago, United States
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27
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Puszynska AM, O'Shea EK. Switching of metabolic programs in response to light availability is an essential function of the cyanobacterial circadian output pathway. eLife 2017; 6. [PMID: 28430105 PMCID: PMC5400509 DOI: 10.7554/elife.23210] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2016] [Accepted: 02/21/2017] [Indexed: 12/22/2022] Open
Abstract
The transcription factor RpaA is the master regulator of circadian transcription in cyanobacteria, driving genome-wide oscillations in mRNA abundance. Deletion of rpaA has no effect on viability in constant light conditions, but renders cells inviable in cycling conditions when light and dark periods alternate. We investigated the mechanisms underlying this viability defect, and demonstrate that the rpaA- strain cannot maintain appropriate energy status at night, does not accumulate carbon reserves during the day, and is defective in transcription of genes crucial for utilization of carbohydrate stores at night. Reconstruction of carbon utilization pathways combined with provision of an external carbon source restores energy charge and viability of the rpaA- strain in light/dark cycling conditions. Our observations highlight how a circadian output pathway controls and temporally coordinates essential pathways in carbon metabolism to maximize fitness of cells facing periodic energy limitations. DOI:http://dx.doi.org/10.7554/eLife.23210.001 The cycle of day and night is one of the most recurrent and predictable environmental changes on our planet. Consequently, organisms have evolved mechanisms that allow them to measure time over 24 hours and prepare for the periodic changes between light and dark. These mechanisms, known as circadian clocks, alter the activity of some of the organism’s genes in a rhythmic way across the course of a day. This in turn causes certain behaviors and biological activities of the organism to follow a daily cycle. The bacterium Synechococcus elongatus needs to be able to track the daily cycle of light and dark because it performs photosynthesis and depends on sunlight to form sugars, which can later be broken down to release energy. The time information encoded in the circadian clock of S. elongatus is transmitted to the protein RpaA, which drives the regular circadian changes in gene activity in the cell. If RpaA is removed from the cell or prevented from working, S. elongatus can no longer control rhythmic gene activity and is unable to survive the night. To better understand how the circadian system schedules biological tasks to help an organism to survive, Puszynska and O'Shea studied S. elongatus cells. This revealed that the bacteria normally prepare for darkness by storing sugars during the day and activating several genes at dusk to make enzymes that are required to break down stored sugars. This provides the cells with energy that they need to survive the night. But mutant cells that lack the gene that produces RpaA do not prepare for darkness; they do not accumulate a store of sugars during the day or activate the vital genes at dusk. They have low internal energy levels in the dark and they cannot survive long periods of darkness. Providing the mutant cells with sugar and restoring the activity of the genes responsible for breaking down sugar enabled the cells to maintain energy in darkness and survive the night. It therefore appears that one role of the circadian system of S. elongatus is to coordinate building up sugar reserves during the day with breaking down sugar stores to generate energy during the night. Puszynska and O'Shea also found many other genes that are not activated at dusk in the mutant cells. It will therefore be important to study whether other pathways that help cells to survive and grow are defective in these mutant cells. DOI:http://dx.doi.org/10.7554/eLife.23210.002
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Affiliation(s)
- Anna M Puszynska
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, United States.,Faculty of Arts and Sciences Center for Systems Biology, Harvard University, Cambridge, United States.,Howard Hughes Medical Institute, Harvard University, Cambridge, United States
| | - Erin K O'Shea
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, United States.,Faculty of Arts and Sciences Center for Systems Biology, Harvard University, Cambridge, United States.,Howard Hughes Medical Institute, Harvard University, Cambridge, United States.,Department of Chemistry and Chemical Biology, Harvard University, Cambridge, United States
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28
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Paijmans J, Lubensky DK, ten Wolde PR. A thermodynamically consistent model of the post-translational Kai circadian clock. PLoS Comput Biol 2017; 13:e1005415. [PMID: 28296888 PMCID: PMC5371392 DOI: 10.1371/journal.pcbi.1005415] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Revised: 03/29/2017] [Accepted: 02/15/2017] [Indexed: 11/18/2022] Open
Abstract
The principal pacemaker of the circadian clock of the cyanobacterium S. elongatus is a protein phosphorylation cycle consisting of three proteins, KaiA, KaiB and KaiC. KaiC forms a homohexamer, with each monomer consisting of two domains, CI and CII. Both domains can bind and hydrolyze ATP, but only the CII domain can be phosphorylated, at two residues, in a well-defined sequence. While this system has been studied extensively, how the clock is driven thermodynamically has remained elusive. Inspired by recent experimental observations and building on ideas from previous mathematical models, we present a new, thermodynamically consistent, statistical-mechanical model of the clock. At its heart are two main ideas: i) ATP hydrolysis in the CI domain provides the thermodynamic driving force for the clock, switching KaiC between an active conformational state in which its phosphorylation level tends to rise and an inactive one in which it tends to fall; ii) phosphorylation of the CII domain provides the timer for the hydrolysis in the CI domain. The model also naturally explains how KaiA, by acting as a nucleotide exchange factor, can stimulate phosphorylation of KaiC, and how the differential affinity of KaiA for the different KaiC phosphoforms generates the characteristic temporal order of KaiC phosphorylation. As the phosphorylation level in the CII domain rises, the release of ADP from CI slows down, making the inactive conformational state of KaiC more stable. In the inactive state, KaiC binds KaiB, which not only stabilizes this state further, but also leads to the sequestration of KaiA, and hence to KaiC dephosphorylation. Using a dedicated kinetic Monte Carlo algorithm, which makes it possible to efficiently simulate this system consisting of more than a billion reactions, we show that the model can describe a wealth of experimental data. Circadian clocks are biological timekeeping devices with a rhythm of 24 hours in living cells pertaining to all kingdoms of life. They help organisms to coordinate their behavior with the day-night cycle. The circadian clock of the cyanobacterium Synechococcus elongatus is one of the simplest and best characterized clocks in biology. The central clock component is the protein KaiC, which is phosphorylated and dephosphorylated in a cyclical manner with a 24 hr period. While we know from elementary thermodynamics that oscillations require a net turnover of fuel molecules, in this case ATP, how ATP hydrolysis drives the clock has remained elusive. Based on recent experimental observations and building on ideas from existing models, we construct the most detailed mathematical model of this system to date. KaiC consists of two domains, CI and CII, which each can bind ATP, yet only CII can be phosphorylated. Moreover, KaiC can exist in two conformational states, an active one in which the phosphorylation level tends to rise, and an inactive one in which it tends to fall. Our model predicts that ATP hydrolysis in the CI domain is the principal energetic driver of the clock, driving the switching between the two conformational states, while phosphorylation in the CII domain provides the timer for the conformational switch. The coupling between ATP hydrolysis in the CI domain and phosphorylation in the CII domain leads to novel testable predictions.
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Affiliation(s)
| | - David K. Lubensky
- Department of Physics, University of Michigan, Ann Arbor, Michigan, United States of America
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Yu FB, Willis L, Chau RMW, Zambon A, Horowitz M, Bhaya D, Huang KC, Quake SR. Long-term microfluidic tracking of coccoid cyanobacterial cells reveals robust control of division timing. BMC Biol 2017; 15:11. [PMID: 28196492 PMCID: PMC5310064 DOI: 10.1186/s12915-016-0344-4] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2016] [Accepted: 12/10/2016] [Indexed: 01/25/2023] Open
Abstract
Background Cyanobacteria are important agents in global carbon and nitrogen cycling and hold great promise for biotechnological applications. Model organisms such as Synechocystis sp. and Synechococcus sp. have advanced our understanding of photosynthetic capacity and circadian behavior, mostly using population-level measurements in which the behavior of individuals cannot be monitored. Synechocystis sp. cells are small and divide slowly, requiring long-term experiments to track single cells. Thus, the cumulative effects of drift over long periods can cause difficulties in monitoring and quantifying cell growth and division dynamics. Results To overcome this challenge, we enhanced a microfluidic cell-culture device and developed an image analysis pipeline for robust lineage reconstruction. This allowed simultaneous tracking of many cells over multiple generations, and revealed that cells expand exponentially throughout their cell cycle. Generation times were highly correlated for sister cells, but not between mother and daughter cells. Relationships between birth size, division size, and generation time indicated that cell-size control was inconsistent with the “sizer” rule, where division timing is based on cell size, or the “timer” rule, where division occurs after a fixed time interval. Instead, single cell growth statistics were most consistent with the “adder” rule, in which division occurs after a constant increment in cell volume. Cells exposed to light-dark cycles exhibited growth and division only during the light period; dark phases pause but do not disrupt cell-cycle control. Conclusions Our analyses revealed that the “adder” model can explain both the growth-related statistics of single Synechocystis cells and the correlation between sister cell generation times. We also observed rapid phenotypic response to light-dark transitions at the single cell level, highlighting the critical role of light in cyanobacterial cell-cycle control. Our findings suggest that by monitoring the growth kinetics of individual cells we can build testable models of circadian control of the cell cycle in cyanobacteria. Electronic supplementary material The online version of this article (doi:10.1186/s12915-016-0344-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Feiqiao Brian Yu
- Department of Electrical Engineering, Stanford University, Stanford, CA, 94305, USA.,Department of Bioengineering, Stanford University, Stanford, CA, 94305, USA
| | - Lisa Willis
- Department of Bioengineering, Stanford University, Stanford, CA, 94305, USA.,Sainsbury Laboratory, Cambridge University, Cambridge, CB2 1LR, UK
| | | | - Alessandro Zambon
- Department of Bioengineering, Stanford University, Stanford, CA, 94305, USA.,Department of Industrial Engineering, University of Padova, Padova, 35131, Italy
| | - Mark Horowitz
- Department of Electrical Engineering, Stanford University, Stanford, CA, 94305, USA
| | - Devaki Bhaya
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, 94305, USA.
| | - Kerwyn Casey Huang
- Department of Bioengineering, Stanford University, Stanford, CA, 94305, USA. .,Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA, 94305, USA.
| | - Stephen R Quake
- Department of Bioengineering, Stanford University, Stanford, CA, 94305, USA. .,Chan Zuckerberg Biohub, San Francisco, CA, 94158, USA.
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30
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Mora-García S, de Leone MJ, Yanovsky M. Time to grow: circadian regulation of growth and metabolism in photosynthetic organisms. CURRENT OPINION IN PLANT BIOLOGY 2017; 35:84-90. [PMID: 27912128 DOI: 10.1016/j.pbi.2016.11.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 11/10/2016] [Accepted: 11/11/2016] [Indexed: 05/21/2023]
Abstract
Circadian clocks are molecular devices that help adjust organisms to periodic environmental changes. Although formally described as self-sustaining oscillators that are synchronized by external cues and produce defined outputs, it is increasingly clear that physiological processes not only are regulated by, but also regulate the function of the clock. We discuss three recent examples of the intimate relationships between the function of the clock, growth and metabolism in photosynthetic organisms: the daily tracking of sun by sunflowers, the fine computations plants and cyanobacteria perform to manage carbon reserves and prevent starvation, and the changes in clock parameters that went along with domestication of tomato.
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Affiliation(s)
- Santiago Mora-García
- Fundación Instituto Leloir, Av. Patricias Argentinas 435, 1405 Buenos Aires, Argentina.
| | - María José de Leone
- Fundación Instituto Leloir, Av. Patricias Argentinas 435, 1405 Buenos Aires, Argentina
| | - Marcelo Yanovsky
- Fundación Instituto Leloir, Av. Patricias Argentinas 435, 1405 Buenos Aires, Argentina.
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31
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Westermark S, Steuer R. Toward Multiscale Models of Cyanobacterial Growth: A Modular Approach. Front Bioeng Biotechnol 2016; 4:95. [PMID: 28083530 PMCID: PMC5183639 DOI: 10.3389/fbioe.2016.00095] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Accepted: 12/09/2016] [Indexed: 11/29/2022] Open
Abstract
Oxygenic photosynthesis dominates global primary productivity ever since its evolution more than three billion years ago. While many aspects of phototrophic growth are well understood, it remains a considerable challenge to elucidate the manifold dependencies and interconnections between the diverse cellular processes that together facilitate the synthesis of new cells. Phototrophic growth involves the coordinated action of several layers of cellular functioning, ranging from the photosynthetic light reactions and the electron transport chain, to carbon-concentrating mechanisms and the assimilation of inorganic carbon. It requires the synthesis of new building blocks by cellular metabolism, protection against excessive light, as well as diurnal regulation by a circadian clock and the orchestration of gene expression and cell division. Computational modeling allows us to quantitatively describe these cellular functions and processes relevant for phototrophic growth. As yet, however, computational models are mostly confined to the inner workings of individual cellular processes, rather than describing the manifold interactions between them in the context of a living cell. Using cyanobacteria as model organisms, this contribution seeks to summarize existing computational models that are relevant to describe phototrophic growth and seeks to outline their interactions and dependencies. Our ultimate aim is to understand cellular functioning and growth as the outcome of a coordinated operation of diverse yet interconnected cellular processes.
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Affiliation(s)
- Stefanie Westermark
- Fachinstitut für Theoretische Biologie (ITB), Institut für Biologie, Humboldt-Universität zu Berlin , Berlin , Germany
| | - Ralf Steuer
- Fachinstitut für Theoretische Biologie (ITB), Institut für Biologie, Humboldt-Universität zu Berlin , Berlin , Germany
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32
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Early JO, Curtis AM. Immunometabolism: Is it under the eye of the clock? Semin Immunol 2016; 28:478-490. [DOI: 10.1016/j.smim.2016.10.006] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 10/13/2016] [Accepted: 10/14/2016] [Indexed: 02/06/2023]
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33
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Iijima H, Shirai T, Okamoto M, Pinto F, Tamagnini P, Hasunuma T, Kondo A, Hirai MY, Osanai T. Metabolomics-based analysis revealing the alteration of primary carbon metabolism by the genetic manipulation of a hydrogenase HoxH in Synechocystis sp. PCC 6803. ALGAL RES 2016. [DOI: 10.1016/j.algal.2016.06.026] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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34
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Hurley JM, Loros JJ, Dunlap JC. Circadian Oscillators: Around the Transcription-Translation Feedback Loop and on to Output. Trends Biochem Sci 2016; 41:834-846. [PMID: 27498225 DOI: 10.1016/j.tibs.2016.07.009] [Citation(s) in RCA: 129] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Revised: 07/10/2016] [Accepted: 07/14/2016] [Indexed: 12/20/2022]
Abstract
From cyanobacteria to mammals, organisms have evolved timing mechanisms to adapt to environmental changes in order to optimize survival and improve fitness. To anticipate these regular daily cycles, many organisms manifest ∼24h cell-autonomous oscillations that are sustained by transcription-translation-based or post-transcriptional negative-feedback loops that control a wide range of biological processes. With an eye to identifying emerging common themes among cyanobacterial, fungal, and animal clocks, some major recent developments in the understanding of the mechanisms that regulate these oscillators and their output are discussed. These include roles for antisense transcription, intrinsically disordered proteins, codon bias in clock genes, and a more focused discussion of post-transcriptional and translational regulation as a part of both the oscillator and output.
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Affiliation(s)
- Jennifer M Hurley
- Department of Biological Sciences, Rensselaer Polytechnic Institute, Troy, NY 12180, USA.
| | - Jennifer J Loros
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA
| | - Jay C Dunlap
- Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA.
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35
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Skanata A, Kussell E. Evolutionary Phase Transitions in Random Environments. PHYSICAL REVIEW LETTERS 2016; 117:038104. [PMID: 27472146 PMCID: PMC5697730 DOI: 10.1103/physrevlett.117.038104] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Indexed: 06/06/2023]
Abstract
We present analytical results for long-term growth rates of structured populations in randomly fluctuating environments, which we apply to predict how cellular response networks evolve. We show that networks which respond rapidly to a stimulus will evolve phenotypic memory exclusively under random (i.e., nonperiodic) environments. We identify the evolutionary phase diagram for simple response networks, which we show can exhibit both continuous and discontinuous transitions. Our approach enables exact analysis of diverse evolutionary systems, from viral epidemics to emergence of drug resistance.
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Affiliation(s)
- Antun Skanata
- Department of Biology, Center for Genomics and Systems Biology, New York University, New York, NY
| | - Edo Kussell
- Department of Biology, Center for Genomics and Systems Biology, New York University, New York, NY
- Department of Physics, New York University, New York, NY
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36
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Ma KC, Perli SD, Lu TK. Foundations and Emerging Paradigms for Computing in Living Cells. J Mol Biol 2016; 428:893-915. [DOI: 10.1016/j.jmb.2016.02.018] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Revised: 02/13/2016] [Accepted: 02/15/2016] [Indexed: 01/11/2023]
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