1
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Lu GM, Hu HH, Chang CC, Zhong J, Zhou X, Guo CJ, Zhang T, Li YL, Yin B, Liu JL. Structural basis of human PRPS2 filaments. Cell Biosci 2023; 13:100. [PMID: 37248548 DOI: 10.1186/s13578-023-01037-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Accepted: 04/19/2023] [Indexed: 05/31/2023] Open
Abstract
BACKGROUND PRPP synthase (PRPS) transfers the pyrophosphate groups from ATP to ribose-5-phosphate to produce 5-phosphate ribose-1-pyrophosphate (PRPP), a key intermediate in the biosynthesis of several metabolites including nucleotides, dinucleotides and some amino acids. There are three PRPS isoforms encoded in human genome. While human PRPS1 (hPRPS1) and human PRPS2 (hPRPS2) are expressed in most tissues, human PRPS3 (hPRPS3) is exclusively expressed in testis. Although hPRPS1 and hPRPS2 share 95% sequence identity, hPRPS2 has been shown to be less sensitive to allosteric inhibition and specifically upregulated in certain cancers in the translational level. Recent studies demonstrate that PRPS can form a subcellular compartment termed the cytoophidium in multiple organisms across prokaryotes and eukaryotes. Forming filaments and cytoophidia is considered as a distinctive mechanism involving the polymerization of the protein. Previously we solved the filament structures of Escherichia coli PRPS (ecPRPS) using cryo-electron microscopy (cryo-EM) 1. RESULTS Order to investigate the function and molecular mechanism of hPRPS2 polymerization, here we solve the polymer structure of hPRPS2 at 3.08 Å resolution. hPRPS2 hexamers stack into polymers in the conditions with the allosteric/competitive inhibitor ADP. The binding modes of ADP at the canonical allosteric site and at the catalytic active site are clearly determined. A point mutation disrupting the inter-hexamer interaction prevents hPRPS2 polymerization and results in significantly reduced catalytic activity. CONCLUSION Findings suggest that the regulation of hPRPS2 polymer is distinct from ecPRPS polymer and provide new insights to the regulation of hPRPS2 with structural basis.
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Affiliation(s)
- Guang-Ming Lu
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Huan-Huan Hu
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Chia-Chun Chang
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Jiale Zhong
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Xian Zhou
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Chen-Jun Guo
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Tianyi Zhang
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Yi-Lan Li
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Boqi Yin
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Ji-Long Liu
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China.
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, UK.
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2
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You DD, Zhou XL, Wang QQ, Liu JL. Cytoophidia safeguard binucleation of Drosophila male accessory gland cells. Exp Cell Res 2023; 422:113433. [PMID: 36423659 DOI: 10.1016/j.yexcr.2022.113433] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 11/16/2022] [Accepted: 11/19/2022] [Indexed: 11/23/2022]
Abstract
Although most cells are mononuclear, the nucleus can exist in the form of binucleate or even multinucleate to respond to different physiological processes. The male accessory gland of Drosophila is the organ that produces semen, and its main cells are binucleate. Here we observe that CTP synthase (CTPS) forms filamentous cytoophidia in binuclear main cells, primarily located at the cell boundary. In CTPSH355A, a point mutation that destroys the formation of cytoophidia, we find that the nucleation mode of the main cells changes, including mononucleates and vertical distribution of binucleates. Although the overexpression of CTPSH355A can restore the level of CTPS protein, it will neither form cytoophidia nor eliminate the abnormal nucleation pattern. Therefore, our data indicate that there is an unexpected functional link between the formation of cytoophidia and the maintenance of binucleation in Drosophila main cells.
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Affiliation(s)
- Dong-Dong You
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Xiao-Li Zhou
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Qiao-Qi Wang
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Ji-Long Liu
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China; Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, United Kingdom.
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3
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Andreadis C, Li T, Liu JL. Ubiquitination regulates cytoophidium assembly in Schizosaccharomyces pombe. Exp Cell Res 2022; 420:113337. [PMID: 36087798 DOI: 10.1016/j.yexcr.2022.113337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2022] [Revised: 08/26/2022] [Accepted: 08/27/2022] [Indexed: 12/30/2022]
Abstract
CTP synthase (CTPS), a metabolic enzyme responsible for the de novo synthesis of CTP, can form filamentous structures termed cytoophidia, which are evolutionarily conserved from bacteria to humans. Here we used Schizosaccharomyces pombe to study the cytoophidium assembly regulation by ubiquitination. We tested the CTP synthase's capacity to be post-translationally modified by ubiquitin or be affected by the ubiquitination state of the cell and showed that ubiquitination is important for the maintenance of the CTPS filamentous structure in fission yeast. We have identified proteins which are in complex with CTPS, including specific ubiquitination regulators which significantly affect CTPS filamentation, and mapped probable ubiquitination targets on CTPS. Furthermore, we discovered that a cohort of deubiquitinating enzymes is important for the regulation of cytoophidium's filamentous morphology. Our study provides a framework for the analysis of the effects that ubiquitination and deubiquitination have on the formation of cytoophidia.
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Affiliation(s)
- Christos Andreadis
- School of Life Science and Technology, ShanghaiTech University, 201210, Shanghai, China
| | - Tianhao Li
- School of Life Science and Technology, ShanghaiTech University, 201210, Shanghai, China
| | - Ji-Long Liu
- School of Life Science and Technology, ShanghaiTech University, 201210, Shanghai, China; Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, United Kingdom.
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4
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Chang CC, Peng M, Zhong J, Zhang Z, Keppeke GD, Sung LY, Liu JL. Molecular crowding facilitates bundling of IMPDH polymers and cytoophidium formation. Cell Mol Life Sci 2022; 79:420. [PMID: 35833994 DOI: 10.1007/s00018-022-04448-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 06/14/2022] [Accepted: 06/21/2022] [Indexed: 11/29/2022]
Abstract
The cytoophidium is a unique type of membraneless compartment comprising of filamentous protein polymers. Inosine monophosphate dehydrogenase (IMPDH) catalyzes the rate-limiting step of de novo GTP biosynthesis and plays critical roles in active cell metabolism. However, the molecular regulation of cytoophidium formation is poorly understood. Here we show that human IMPDH2 polymers bundle up to form cytoophidium-like aggregates in vitro when macromolecular crowders are present. The self-association of IMPDH polymers is suggested to rely on electrostatic interactions. In cells, the increase of molecular crowding with hyperosmotic medium induces cytoophidia, while the decrease of that by the inhibition of RNA synthesis perturbs cytoophidium assembly. In addition to IMPDH, CTPS and PRPS cytoophidium could be also induced by hyperosmolality, suggesting a universal phenomenon of cytoophidium-forming proteins. Finally, our results indicate that the cytoophidium can prolong the half-life of IMPDH, which is proposed to be one of conserved functions of this subcellular compartment.
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Affiliation(s)
- Chia-Chun Chang
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China.,Institute of Biotechnology, National Taiwan University, Taipei, 106, Taiwan
| | - Min Peng
- Institute of Biotechnology, National Taiwan University, Taipei, 106, Taiwan
| | - Jiale Zhong
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Ziheng Zhang
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Gerson Dierley Keppeke
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China.,Rheumatology Division, Escola Paulista de Medicina, Universidade Federal de Sao Paulo, Sao Paulo, SP, 04023-062, Brazil
| | - Li-Ying Sung
- Institute of Biotechnology, National Taiwan University, Taipei, 106, Taiwan.,Agricultural Biotechnology Research Center, Academia Sinica, Taipei, 115, Taiwan
| | - Ji-Long Liu
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China. .,Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, UK.
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5
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Wu Z, Liu JL. CTP synthase does not form cytoophidia in Drosophila interfollicular stalks. Exp Cell Res 2022; 418:113250. [PMID: 35691380 DOI: 10.1016/j.yexcr.2022.113250] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2022] [Revised: 06/05/2022] [Accepted: 06/06/2022] [Indexed: 11/26/2022]
Abstract
CTP synthase (CTPS) catalyzes the final step of de novo synthesis of the nucleotide CTP. In 2010, CTPS has been found to form filamentous structures termed cytoophidia in Drosophila follicle cells and germline cells. Subsequently, cytoophidia have been reported in many species across three domains of life: bacteria, eukaryotes and archaea. Forming cytoophidia appears to be a highly conserved and ancient property of CTPS. To our surprise, here we find that polar cells and stalk cells, two specialized types of cells composing Drosophila interfollicular stalks, do not possess obvious cytoophidia. We show that Myc level is low in these two types of cells. Treatment with a glutamine analog, 6-diazo-5-oxo-l-norleucine (DON), increases cytoophidium assembly in main follicle cells, but not in polar cells or stalk cells. Moreover, overexpressing Myc induces cytoophidium formation in stalk cells. When CTPS is overexpressed, cytoophidia can be observed both in stalk cells and polar cells. Our findings provide an interesting paradigm for the in vivo study of cytoophidium assembly and disassembly among different populations of follicle cells.
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Affiliation(s)
- Zheng Wu
- School of Life Science and Technology, ShanghaiTech University, 230 Haike Road, 201210, Shanghai, China
| | - Ji-Long Liu
- School of Life Science and Technology, ShanghaiTech University, 230 Haike Road, 201210, Shanghai, China; Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford, OX1 3PT, United Kingdom.
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6
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Thangadurai S, Bajgiran M, Manickam S, Mohana-Kumaran N, Azzam G. CTP synthase: the hissing of the cellular serpent. Histochem Cell Biol 2022; 158:517-534. [PMID: 35881195 PMCID: PMC9314535 DOI: 10.1007/s00418-022-02133-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/26/2022] [Indexed: 12/24/2022]
Abstract
CTP biosynthesis is carried out by two pathways: salvage and de novo. CTPsyn catalyzes the latter. The study of CTPsyn activity in mammalian cells began in the 1970s, and various fascinating discoveries were made regarding the role of CTPsyn in cancer and development. However, its ability to fit into a cellular serpent-like structure, termed 'cytoophidia,' was only discovered a decade ago by three independent groups of scientists. Although the self-assembly of CTPsyn into a filamentous structure is evolutionarily conserved, the enzyme activity upon this self-assembly varies in different species. CTPsyn is required for cellular development and homeostasis. Changes in the expression of CTPsyn cause developmental changes in Drosophila melanogaster. A high level of CTPsyn activity and formation of cytoophidia are often observed in rapidly proliferating cells such as in stem and cancer cells. Meanwhile, the deficiency of CTPsyn causes severe immunodeficiency leading to immunocompromised diseases caused by bacteria, viruses, and parasites, making CTPsyn an attractive therapeutic target. Here, we provide an overview of the role of CTPsyn in cellular and disease perspectives along with its potential as a drug target.
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Affiliation(s)
- Shallinie Thangadurai
- grid.11875.3a0000 0001 2294 3534School of Biological Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia
| | - Morteza Bajgiran
- grid.11875.3a0000 0001 2294 3534School of Biological Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia
| | - Sharvin Manickam
- grid.11875.3a0000 0001 2294 3534School of Biological Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia
| | - Nethia Mohana-Kumaran
- grid.11875.3a0000 0001 2294 3534School of Biological Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia
| | - Ghows Azzam
- grid.11875.3a0000 0001 2294 3534School of Biological Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia ,grid.454125.3Malaysia Genome and Vaccine Institute, National Institutes of Biotechnology Malaysia, Jalan Bangi, 43000 Kajang, Selangor Malaysia
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7
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Zhou Y, Liu J, Zhang Y, Liu JL. Drosophila intestinal homeostasis requires CTP synthase. Exp Cell Res 2021; 408:112838. [PMID: 34560103 DOI: 10.1016/j.yexcr.2021.112838] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 09/12/2021] [Accepted: 09/17/2021] [Indexed: 11/22/2022]
Abstract
CTP synthase (CTPS) senses all four nucleotides and forms filamentous structures termed cytoophidia in all three domains of life. How CTPS and cytoophidia function in a developmental context, however, remains underexplored. We report that CTPS forms cytoophidia in a subset of cells in the Drosophila midgut. We found that cytoophidia exist in intestinal stem cells (ISC) and enteroblasts in similar proportions. Both refeeding after starvation and feeding with dextran sulfate sodium (DSS) induce ISC proliferation and elongate cytoophidia. Knockdown of CTPS inhibits ISC proliferation. Remarkably, disruption of CTPS cytoophidia inhibits DSS-induced ISC proliferation. Taken together, these data suggest that both the expression level and the filament-form property of CTPS are crucial for intestinal homeostasis in Drosophila.
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8
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Chang CC, Keppeke GD, Antos CL, Peng M, Andrade LEC, Sung LY, Liu JL. CTPS forms the cytoophidium in zebrafish. Exp Cell Res 2021; 405:112684. [PMID: 34129847 DOI: 10.1016/j.yexcr.2021.112684] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2021] [Revised: 05/30/2021] [Accepted: 06/01/2021] [Indexed: 12/26/2022]
Abstract
Cytidine triphosphate synthase (CTPS) catalyzes the rate-limiting step of de novo CTP biosynthesis. An intracellular structure of CTPS, the cytoophidium, has been found in many organisms including prokaryotes and eukaryotes. Formation of the cytoophidium has been suggested to regulate the activity and stability of CTPS and may participate in certain physiological events. Herein, we demonstrate that both CTPS1a and CTPS1b in zebrafish are able to form the cytoophidium in cultured cells. A point mutation, H355A, abrogates cytoophidium assembly of zebrafish CTPS1a and CTPS1b. In addition, we show the presence of CTPS cytoophidia in multiple tissues of larval and adult fish under normal conditions, while treatment with a CTPS inhibitor 6-diazo-5-oxo-l-norleucine (DON) can induce more cytoophidia in some tissues. Our findings reveal that forming the CTPS cytoophidium is a natural phenomenon of zebrafish and provide valuable information for future research on the physiological importance of this intracellular structure in vertebrates.
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Affiliation(s)
- Chia-Chun Chang
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Gerson Dierley Keppeke
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China; Rheumatology Division, Escola Paulista de Medicina, Universidade Federal de Sao Paulo, Sao Paulo, SP 04023-062, Brazil
| | - Christopher L Antos
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Min Peng
- Institute of Biotechnology, National Taiwan University, Taipei, 106, Taiwan
| | - Luis Eduardo Coelho Andrade
- Rheumatology Division, Escola Paulista de Medicina, Universidade Federal de Sao Paulo, Sao Paulo, SP 04023-062, Brazil
| | - Li-Ying Sung
- Institute of Biotechnology, National Taiwan University, Taipei, 106, Taiwan; Agricultural Biotechnology Research Center, Academia Sinica, Taipei, 115, Taiwan
| | - Ji-Long Liu
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China; Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, United Kingdom.
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9
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Keppeke GD, Chang CC, Antos CL, Peng M, Sung LY, Andrade LEC, Liu JL. IMPDH forms the cytoophidium in zebrafish. Dev Biol 2021; 478:89-101. [PMID: 34048735 DOI: 10.1016/j.ydbio.2021.05.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2020] [Revised: 05/17/2021] [Accepted: 05/18/2021] [Indexed: 02/07/2023]
Abstract
Inosine monophosphate dehydrogenase (IMPDH) catalyzes the rate-limiting step in de novo guanine nucleotide biosynthesis. Its activity is negatively regulated by the binding of GTP. IMPDH can form a membraneless subcellular structure termed the cytoophidium in response to certain changes in the metabolic status of the cell. The polymeric form of IMPDH, which is the subunit of the cytoophidium, has been shown to be more resistant to the inhibition by GTP at physiological concentrations, implying a functional correlation between cytoophidium formation and the upregulation of GTP biosynthesis. Herein we demonstrate that zebrafish IMPDH1b and IMPDH2 isoforms can assemble abundant cytoophidium in most of cultured cells under stimuli, while zebrafish IMPDH1a shows distinctive properties of forming the cytoophidium in different cell types. Point mutations that disrupt cytoophidium structure in mammalian models also prevent the aggregation of zebrafish IMPDHs. In addition, we discover the presence of the IMPDH cytoophidium in various tissues of larval and adult fish under normal growth conditions. Our results reveal that polymerization and cytoophidium assembly of IMPDH can be a regulatory machinery conserved among vertebrates, and with specific physiological purposes.
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Affiliation(s)
- Gerson Dierley Keppeke
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China; Rheumatology Division, Escola Paulista de Medicina, Universidade Federal de Sao Paulo, Sao Paulo, SP, 04023-062, Brazil
| | - Chia-Chun Chang
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Christopher L Antos
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Min Peng
- Institute of Biotechnology, National Taiwan University, Taipei, 106, Taiwan
| | - Li-Ying Sung
- Institute of Biotechnology, National Taiwan University, Taipei, 106, Taiwan; Agricultural Biotechnology Research Center, Academia Sinica, Taipei, 115, Taiwan
| | - Luis Eduardo Coelho Andrade
- Rheumatology Division, Escola Paulista de Medicina, Universidade Federal de Sao Paulo, Sao Paulo, SP, 04023-062, Brazil
| | - Ji-Long Liu
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China.
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10
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Peng M, Chang CC, Liu JL, Sung LY. CTPS and IMPDH form cytoophidia in developmental thymocytes. Exp Cell Res 2021; 405:112662. [PMID: 34022203 DOI: 10.1016/j.yexcr.2021.112662] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 05/13/2021] [Accepted: 05/15/2021] [Indexed: 02/06/2023]
Abstract
The cytoophidium, a filamentous structure formed by metabolic enzymes, has emerged as a novel regulatory machinery for certain proteins. The rate-limiting enzymes of de novo CTP and GTP synthesis, cytidine triphosphate synthase (CTPS) and inosine monophosphate dehydrogenase (IMPDH), are the most characterized cytoophidium-forming enzymes in mammalian models. Although the assembly of CTPS cytoophidia has been demonstrated in various organisms including multiple human cancers, a systemic survey for the presence of CTPS cytoophidia in mammalian tissues in normal physiological conditions has not yet been reported. Herein, we examine major organs of adult mouse and observe that CTPS cytoophidia are displayed by a specific thymocyte population ranging between DN3 to early DP stages. Most of these cytoophidium-presenting cells have both CTPS and IMPDH cytoophidia and undergo rapid cell proliferation. In addition, we show that cytoophidium formation is associated with active glycolytic metabolism as the cytoophidium-presenting cells exhibit higher levels of c-Myc, phospho-Akt and PFK. Inhibition of glycolysis with 2DG, however, disrupts most of cytoophidium structures and impairs cell proliferation. Our findings not only indicate that the regulation of CTPS and IMPDH cytoophidia are correlated with the metabolic switch triggered by pre-TCR signaling, but also suggest physiological roles of the cytoophidium in thymocyte development.
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Affiliation(s)
- Min Peng
- Institute of Biotechnology, National Taiwan University, Taipei, 106, Taiwan
| | - Chia-Chun Chang
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Ji-Long Liu
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China.
| | - Li-Ying Sung
- Institute of Biotechnology, National Taiwan University, Taipei, 106, Taiwan; Agricultural Biotechnology Research Center, Academia Sinica, Taipei, 115, Taiwan; Animal Resource Center, National Taiwan University, Taipei, 106, Taiwan.
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11
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Feng HC, Andreadis C, Liu JL. Histone transcription regulator Slm9 is required for cytoophidium biogenesis. Exp Cell Res 2021; 403:112582. [PMID: 33812868 DOI: 10.1016/j.yexcr.2021.112582] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 03/25/2021] [Accepted: 03/28/2021] [Indexed: 11/23/2022]
Abstract
The cytoophidium, a subcellular structure composed of CTP synthase, can be observed during the division of Schizosaccharomyces pombe. Cytoophidium formation changes periodically with the cell cycle of yeast cells. Here, we find that histone chaperone Slm9 is required for the integrity of cytoophidia in fission yeast. When the slm9 gene is knocked out, we observe that morphological characteristics, the abundance of cytoophidia and the division of the yeast cells are significantly affected. Fragmented cytoophidia occur in slm9 mutant cells, a phenomenon rarely observed in wild-type cells. Our study reveals a potential link between a chromosomal regulatory factor and cytoophidium biogenesis.
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12
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Wang QQ, Zhao PA, Tastan ÖY, Liu JL. Polarised maintenance of cytoophidia in Drosophila follicle epithelia. Exp Cell Res 2021; 402:112564. [PMID: 33737069 DOI: 10.1016/j.yexcr.2021.112564] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 03/06/2021] [Accepted: 03/09/2021] [Indexed: 12/20/2022]
Abstract
The metabolic enzyme CTP synthase (CTPS) can form filamentous structures named cytoophidia in numerous types of cells, including follicle cells. However, the regulation of cytoophidium assembly remains elusive. The apicobasal polarity, a defining characteristic of Drosophila follicle epithelium, is established and regulated by a variety of membrane domains. Here we show that CTPS can form cytoophidia in Drosophila epithelial follicle cells. Cytoophidia localise to the basolateral side of follicle cells. If apical polarity regulators are knocked down, cytoophidia become unstable and distribute abnormally. Knockdown of basolateral polarity regulators has no significant effect on cytoophidia, even though the polarity is disturbed. Our results indicate that cytoophidia are maintained via polarised distribution on the basolateral side of Drosophila follicle epithelia, which is primarily achieved through the apical polarity regulators.
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Affiliation(s)
- Qiao-Qi Wang
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China; Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China; University of Chinese Academy of Sciences, Beijing, China
| | - Peiyao A Zhao
- MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, United Kingdom
| | - Ömür Y Tastan
- MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, United Kingdom
| | - Ji-Long Liu
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China; MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, United Kingdom.
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13
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Abstract
Live-cell imaging is widely used by researchers to study cellular dynamics and obtain a deep understanding of cell biological processes. Keeping cells in the proper growing environment and immobilizing the cells are essential for the imaging of live yeast cells. Here we describe a protocol for monitoring cytoophidia in Saccharomyces cerevisiae and Schizosaccharomyces pombe using inverted confocal fluorescence microscopy. This protocol includes yeast culture, sample preparation, fluorescence imaging, and data analysis.
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Affiliation(s)
- Shanshan Zhang
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
- Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, China
| | - Hui Li
- School of Systems Science, Beijing Normal University, Beijing, China
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Ji-Long Liu
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China.
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK.
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14
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Zhang Y, Liu J, Liu JL. The atlas of cytoophidia in Drosophila larvae. J Genet Genomics 2020; 47:321-331. [PMID: 32912804 DOI: 10.1016/j.jgg.2020.06.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 06/07/2020] [Accepted: 06/21/2020] [Indexed: 02/08/2023]
Abstract
In 2010, cytidine 5'-triphosphate synthase (CTPS) was reported to form the filamentous or serpentine structure in Drosophila, which we termed the cytoophidium. In the last decade, CTPS filaments/cytoophidia have been found in bacteria, budding yeast, human cells, mice, fission yeast, plants, and archaea, indicating that this mechanism is highly conserved in evolution. In addition to CTPS, other metabolic enzymes have been identified to have the characteristics of forming cytoophidia or similar advanced structures, demonstrating that this is a basic strategy of cells. Nevertheless, our understanding of the physiological function of the cytoophidium remains incomplete and elusive. Here, we took the larva of Drosophila melanogaster as a model to systematically describe the localization and distribution of cytoophidia in different tissues during larval development. We found that the distribution pattern of CTPS cytoophidia is dynamic and heterogenic in larval tissues. Our study provides a road map for further understanding of the function and regulatory mechanism of cytoophidia.
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Affiliation(s)
- Yuanbing Zhang
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China; University of Chinese Academy of Sciences, Beijing, 100049, China; Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Jingnan Liu
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Ji-Long Liu
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China.
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Zhang B, Tastan ÖY, Zhou X, Guo CJ, Liu X, Thind A, Hu HH, Zhao S, Liu JL. The proline synthesis enzyme P5CS forms cytoophidia in Drosophila. J Genet Genomics 2020; 47:131-143. [PMID: 32317150 DOI: 10.1016/j.jgg.2020.02.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 02/25/2020] [Accepted: 02/29/2020] [Indexed: 01/26/2023]
Abstract
Compartmentation of enzymes via filamentation has arisen as a mechanism for the regulation of metabolism. In 2010, three groups independently reported that CTP synthase (CTPS) can assemble into a filamentous structure termed the cytoophidium. In searching for CTPS-interacting proteins, here we perform a yeast two-hybrid screening of Drosophila proteins and identify a putative CTPS-interacting protein, △1-pyrroline-5-carboxylate synthase (P5CS). Using the Drosophila follicle cell as the in vivo model, we confirm that P5CS forms cytoophidia, which are associated with CTPS cytoophidia. Overexpression of P5CS increases the length of CTPS cytoophidia. Conversely, filamentation of CTPS affects the morphology of P5CS cytoophidia. Finally, in vitro analyses confirm the filament-forming property of P5CS. Our work links CTPS with P5CS, two enzymes involved in the rate-limiting steps in pyrimidine and proline biosynthesis, respectively.
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Affiliation(s)
- Bo Zhang
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China; Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ömür Y Tastan
- MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, United Kingdom
| | - Xian Zhou
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Chen-Jun Guo
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Xuyang Liu
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China; iHuman Institute, ShanghaiTech University, Shanghai, 201210, China
| | - Aaron Thind
- MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, United Kingdom
| | - Huan-Huan Hu
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Suwen Zhao
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China; iHuman Institute, ShanghaiTech University, Shanghai, 201210, China
| | - Ji-Long Liu
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China; MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, United Kingdom.
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Zhou X, Guo CJ, Hu HH, Zhong J, Sun Q, Liu D, Zhou S, Chang CC, Liu JL. Drosophila CTP synthase can form distinct substrate- and product-bound filaments. J Genet Genomics 2019; 46:537-545. [PMID: 31902586 DOI: 10.1016/j.jgg.2019.11.006] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 11/07/2019] [Accepted: 11/10/2019] [Indexed: 01/26/2023]
Abstract
Intracellular compartmentation is a key strategy for the functioning of a cell. In 2010, several studies revealed that the metabolic enzyme CTP synthase (CTPS) can form filamentous structures termed cytoophidia in prokaryotic and eukaryotic cells. However, recent structural studies showed that CTPS only forms inactive product-bound filaments in bacteria while forming active substrate-bound filaments in eukaryotic cells. In this study, using negative staining and cryo-electron microscopy, we demonstrate that Drosophila CTPS, whether in substrate-bound or product-bound form, can form filaments. Our results challenge the previous model and indicate that substrate-bound and product-bound filaments can coexist in the same species. We speculate that the ability to switch between active and inactive cytoophidia in the same cells provides an additional layer of metabolic regulation.
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Affiliation(s)
- Xian Zhou
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Chen-Jun Guo
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Huan-Huan Hu
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China; Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jiale Zhong
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China; Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Qianqian Sun
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China; iHuman Institute, ShanghaiTech University, Shanghai, 201210, China
| | - Dandan Liu
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China; iHuman Institute, ShanghaiTech University, Shanghai, 201210, China
| | - Shuang Zhou
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China; Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Chia Chun Chang
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Ji-Long Liu
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China.
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Dzaki N, Woo WK, Thangadurai S, Azzam G. MicroRNA regulation of CTP synthase and cytoophidium in Drosophila melanogaster. Exp Cell Res 2019; 385:111688. [PMID: 31678212 DOI: 10.1016/j.yexcr.2019.111688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 10/24/2019] [Accepted: 10/25/2019] [Indexed: 11/21/2022]
Abstract
CTPsyn is a crucial metabolic enzyme which synthesizes CTP nucleotides. It has the extraordinary ability to compartmentalize into filaments termed cytoophidia. Though the structure is evolutionarily conserved across kingdoms, the mechanisms behind their formation remain unknown. MicroRNAs (miRNAs) are short single-stranded RNA capable of directing mRNA silencing and degradation. D. melanogaster has a high total gene count to miRNA gene number ratio, alluding to the possibility that CTPsyn too may come under their regulation. A thorough miRNA overexpression involving 123 miRNAs was conducted, followed by CTPsyn-specific staining upon cytoophidia-rich egg chambers. This revealed a small group of candidates which confer either a lengthening or truncating effect on cytoophidia, suggesting they may play a role in regulating CTPsyn. MiR-975 and miR-1014 are both cytoophidia-elongating, whereas miR-190 and miR-932 are cytoophidia-shortening. Though target prediction shows that miR-975 and miR-932 do indeed have binding sites on CTPsyn mRNA, in vitro assays instead revealed a low probability of this being true, instead indicating that the effects asserted by overexpressed miRNAs indirectly reach CTPsyn and its cytoophidia through the actions of middling elements. In silico target prediction and qPCR quantification indicated that, at least for miR-932 and miR-1014, these undetermined elements may be players in fat metabolism. This is the first study to thoroughly investigate miRNAs in connection to CTPsyn expression and activity in any species. The findings presented could serve as a basis for further queries into not only the fundamental aspects of the enzyme's regulation, but may uncover new facets of closely related pathways as well.
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Zhang J, Liu JL. Temperature-sensitive cytoophidium assembly in Schizosaccharomyces pombe. J Genet Genomics 2019; 46:423-432. [PMID: 31611173 PMCID: PMC6868507 DOI: 10.1016/j.jgg.2019.09.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 08/29/2019] [Accepted: 09/09/2019] [Indexed: 12/15/2022]
Abstract
The metabolic enzyme CTP synthase (CTPS) is able to compartmentalize into filaments, termed cytoophidia, in a variety of organisms including bacteria, budding yeast, fission yeast, fruit flies and mammals. A previous study in budding yeast shows that the filament-forming process of CTPS is not sensitive to temperature shift. Here we study CTPS filamentation in the fission yeast Schizosaccharomyces pombe. To our surprise, we find that both the length and the occurrence of cytoophidia in S. pombe decrease upon cold shock or heat shock. The temperature-dependent changes of cytoophidia are fast and reversible. Taking advantage of yeast genetics, we demonstrate that heat-shock proteins are required for cytoophidium assembly in S. pombe. Temperature sensitivity of cytoophidia makes S. pombe an attractive model system for future investigations of this novel membraneless organelle.
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Affiliation(s)
- Jing Zhang
- MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, United Kingdom
| | - Ji-Long Liu
- MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, United Kingdom; School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China.
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19
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Abstract
CTP synthase (CTPsyn) is a metabolic enzyme essential for the de novo synthesis of CTP the nucleotide. CTPsyn can be compartmented into filamentous structures named cytoophidia. Cytoophidia are conserved in a wide range of species and are highly abundant in Drosophila ovaries. Here we report that cytoophidia elongate upon nutrient deprivation, CTPsyn overexpression or heat shock in Drosophila ovaries. We also show that the curvature of cytoophidia changes during apoptosis. Moreover, cytoophidia can be transported from nurse cells to the oocyte via ring canals. Our study demonstrates that cytoophidia can respond to stress and are very dynamic in Drosophila ovaries.
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Affiliation(s)
- Zheng Wu
- School of Life Science and Technology, ShanghaiTech University, 230 Haike Road, 201210 Shanghai, China
| | - Ji-Long Liu
- School of Life Science and Technology, ShanghaiTech University, 230 Haike Road, 201210 Shanghai, China; MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford OX1 3PT, United Kingdom.
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20
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Abstract
CTP synthase (CTPS), the rate-limiting enzyme in de novo CTP biosynthesis, has been demonstrated to assemble into evolutionarily conserved filamentous structures, termed cytoophidia, in Drosophila, bacteria, yeast and mammalian cells. However, the regulation and function of the cytoophidium remain elusive. Here, we provide evidence that the mechanistic target of rapamycin (mTOR) pathway controls cytoophidium assembly in mammalian and Drosophila cells. In mammalian cells, we find that inhibition of mTOR pathway attenuates cytoophidium formation. Moreover, CTPS cytoophidium assembly appears to be dependent on the mTOR complex 1 (mTORC1) mainly. In addition, knockdown of the mTORC1 downstream target S6K1 can inhibit cytoophidium formation, while overexpression of the constitutively active S6K1 reverses mTOR knockdown-induced cytoophidium disassembly. Finally, reducing mTOR protein expression results in a decrease of the length of cytoophidium in Drosophila follicle cells. Therefore, our study connects CTPS cytoophidium formation with the mTOR signaling pathway.
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Affiliation(s)
- Zhe Sun
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Ji-Long Liu
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China; MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, United Kingdom.
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Keppeke GD, Chang CC, Peng M, Chen LY, Lin WC, Pai LM, Andrade LEC, Sung LY, Liu JL. IMP/GTP balance modulates cytoophidium assembly and IMPDH activity. Cell Div 2018; 13:5. [PMID: 29946345 PMCID: PMC6004095 DOI: 10.1186/s13008-018-0038-0] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Accepted: 06/06/2018] [Indexed: 02/07/2023] Open
Abstract
Background Inosine monophosphate dehydrogenase (IMPDH), the rate-limiting enzyme in de novo GTP biosynthesis, plays an important role in cell metabolism and proliferation. It has been demonstrated that IMPDH can aggregate into a macrostructure, termed the cytoophidium, in mammalian cells under a variety of conditions. However, the regulation and function of the cytoophidium are still elusive. Results In this study, we report that spontaneous filamentation of IMPDH is correlated with rapid cell proliferation. Intracellular IMP accumulation promoted cytoophidium assembly, whereas elevated GTP level triggered disassociation of aggregates. By using IMPDH2 CBS domain mutant cell models, which are unable to form the cytoophidium, we have determined that the cytoophidium is of the utmost importance for maintaining the GTP pool and normal cell proliferation in the condition that higher IMPDH activity is required. Conclusions Together, our results suggest a novel mechanism whereby cytoophidium assembly upregulates IMPDH activity and mediates guanine nucleotide homeostasis. Electronic supplementary material The online version of this article (10.1186/s13008-018-0038-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Gerson Dierley Keppeke
- 1Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT UK
| | - Chia Chun Chang
- 1Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT UK.,2Institute of Biotechnology, National Taiwan University, Taipei, 106 Taiwan, ROC
| | - Min Peng
- 2Institute of Biotechnology, National Taiwan University, Taipei, 106 Taiwan, ROC
| | - Li-Yu Chen
- 1Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT UK
| | - Wei-Cheng Lin
- 3Molecular Medicine Research Center, College of Medicine, Chang Gung University, Tao-Yuan, 333 Taiwan, ROC
| | - Li-Mei Pai
- 3Molecular Medicine Research Center, College of Medicine, Chang Gung University, Tao-Yuan, 333 Taiwan, ROC.,4Graduate Institute of Biomedical Science, College of Medicine, Chang Gung University, Tao-Yuan, 333 Taiwan, ROC.,5Department of Biochemistry, College of Medicine, Chang Gung University, Tao-Yuan, 333 Taiwan, ROC
| | - Luis Eduardo Coelho Andrade
- 6Rheumatology Division, Escola Paulista de Medicina, Universidade Federal de Sao Paulo, Sao Paulo, SP 04023-062 Brazil
| | - Li-Ying Sung
- 2Institute of Biotechnology, National Taiwan University, Taipei, 106 Taiwan, ROC.,7Agricultural Biotechnology Research Center, Academia Sinica, Taipei, 115 Taiwan, ROC
| | - Ji-Long Liu
- 1Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT UK.,8School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210 China
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Huang Y, Wang JJ, Ghosh S, Liu JL. Critical roles of CTP synthase N-terminal in cytoophidium assembly. Exp Cell Res 2017; 354:122-133. [PMID: 28342900 PMCID: PMC5405848 DOI: 10.1016/j.yexcr.2017.03.042] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 03/18/2017] [Accepted: 03/20/2017] [Indexed: 01/27/2023]
Abstract
Several metabolic enzymes assemble into distinct intracellular structures in prokaryotes and eukaryotes suggesting an important functional role in cell physiology. The CTP-generating enzyme CTP synthase forms long filamentous structures termed cytoophidia in bacteria, yeast, fruit flies and human cells independent of its catalytic activity. However, the amino acid determinants for protein-protein interaction necessary for polymerisation remained unknown. In this study, we systematically analysed the role of the conserved N-terminal of Drosophila CTP synthase in cytoophidium assembly. Our mutational analyses identified three key amino acid residues within this region that play an instructive role in organisation of CTP synthase into a filamentous structure. Co-transfection assays demonstrated formation of heteromeric CTP synthase filaments which is disrupted by protein carrying a mutated N-terminal alanine residue thus revealing a dominant-negative activity. Interestingly, the dominant-negative activity is supressed by the CTP synthase inhibitor DON. Furthermore, we found that the amino acids at the corresponding position in the human protein exhibit similar properties suggesting conservation of their function through evolution. Our data suggest that cytoophidium assembly is a multi-step process involving N-terminal-dependent sequential interactions between correctly folded structural units and provide insights into the assembly of these enigmatic structures. CTP synthase mutational analyses reveal N-terminal amino acids that regulate filament self-assembly. Amino acid 20 of CTP synthase plays key role in protein interactions necessary for polymerisation. The dominant-negative activity is supressed by CTP synthase inhibitor DON. The functional properties of the amino acids are conserved in Drosophila and human CTP synthases.
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Affiliation(s)
- Yong Huang
- MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, United Kingdom; Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, China
| | - Jin-Jun Wang
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, China
| | - Sanjay Ghosh
- MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, United Kingdom.
| | - Ji-Long Liu
- MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, United Kingdom; School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China.
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Li H, Huang Y, Wang PY, Ye F, Liu JL. Data on dynamic study of cytoophidia in Saccharomyces cerevisiae. Data Brief 2016; 8:40-4. [PMID: 27274529 DOI: 10.1016/j.dib.2016.05.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Revised: 04/18/2016] [Accepted: 05/09/2016] [Indexed: 11/30/2022] Open
Abstract
The data in this paper are related to the research article entitled “Filamentation of metabolic enzymes in Saccharomyces cerevisiae” Q.J. Shen et al. (2016) [1]. Cytoophidia are filamentous structures discovered in fruit flies (doi:10.1016/S1673-8527(09)60046-1) J.L. Liu (2010) [2], bacteria (doi:10.1038/ncb2087) M. Ingerson-Mahar et al. (2010) [3], yeast (doi:10.1083/jcb.201003001; doi:10.1242/bio.20149613) C. Noree et al. (2010) and J. Zhang, L. Hulme, J.L. Liu (2014) [4], [5] and human cells (doi:10.1371/journal.pone.0029690; doi:10.1016/j.jgg.2011.08.004) K. Chen et al. (2011) and W.C. Carcamo et al. (2011) ( [6], [7]. However, there is little research on the motility of the cytoophidia. Here we selected cytoophidia formed by 6 filament-forming proteins in the budding yeast S. cerevisiae, and performed living-cell imaging of cells expressing the proteins fused with GFP. The dynamic features of the six types of cytoophidia were analyzed. In the data, both raw movies and analysed results of the dynamics of cytoophidia are presented.
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Shen QJ, Kassim H, Huang Y, Li H, Zhang J, Li G, Wang PY, Yan J, Ye F, Liu JL. Filamentation of Metabolic Enzymes in Saccharomyces cerevisiae. J Genet Genomics 2016; 43:393-404. [PMID: 27312010 PMCID: PMC4920916 DOI: 10.1016/j.jgg.2016.03.008] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Revised: 03/09/2016] [Accepted: 03/28/2016] [Indexed: 01/21/2023]
Abstract
Compartmentation via filamentation has recently emerged as a novel mechanism for metabolic regulation. In order to identify filament-forming metabolic enzymes systematically, we performed a genome-wide screening of all strains available from an open reading frame-GFP collection in Saccharomyces cerevisiae. We discovered nine novel filament-forming proteins and also confirmed those identified previously. From the 4159 strains, we found 23 proteins, mostly metabolic enzymes, which are capable of forming filaments in vivo. In silico protein-protein interaction analysis suggests that these filament-forming proteins can be clustered into several groups, including translational initiation machinery and glucose and nitrogen metabolic pathways. Using glutamine-utilising enzymes as examples, we found that the culture conditions affect the occurrence and length of the metabolic filaments. Furthermore, we found that two CTP synthases (Ura7p and Ura8p) and two asparagine synthetases (Asn1p and Asn2p) form filaments both in the cytoplasm and in the nucleus. Live imaging analyses suggest that metabolic filaments undergo sub-diffusion. Taken together, our genome-wide screening identifies additional filament-forming proteins in S. cerevisiae and suggests that filamentation of metabolic enzymes is more general than currently appreciated.
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Affiliation(s)
- Qing-Ji Shen
- Medical Research Council Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK
| | - Hakimi Kassim
- Medical Research Council Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK
| | - Yong Huang
- Medical Research Council Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK; Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing 400715, China
| | - Hui Li
- Medical Research Council Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK; Key Laboratory of Soft Matter Physics, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Jing Zhang
- Medical Research Council Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK
| | - Guang Li
- CAS-MPG Partner Institute for Computational Biology, Shanghai Institutes of Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Peng-Ye Wang
- Key Laboratory of Soft Matter Physics, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Jun Yan
- CAS-MPG Partner Institute for Computational Biology, Shanghai Institutes of Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Fangfu Ye
- Key Laboratory of Soft Matter Physics, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Ji-Long Liu
- Medical Research Council Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK.
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Chang CC, Lin WC, Pai LM, Lee HS, Wu SC, Ding ST, Liu JL, Sung LY. Cytoophidium assembly reflects upregulation of IMPDH activity. J Cell Sci 2015; 128:3550-5. [PMID: 26303200 PMCID: PMC4610212 DOI: 10.1242/jcs.175265] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 08/13/2015] [Indexed: 01/18/2023] Open
Abstract
Cytidine triphosphate synthase (CTPS) and inosine monophosphate dehydrogenase (IMPDH) (both of which have two isoforms) can form fiber-like subcellular structures termed 'cytoophidia' under certain circumstances in mammalian cells. Although it has been shown that filamentation of CTPS downregulates its activity by disturbing conformational changes, the activity of IMPDH within cytoophidia is still unclear. Most previous IMPDH cytoophidium studies were performed under conditions involving inhibitors that impair GTP synthesis. Here, we show that IMPDH forms cytoophidia without inhibition of GTP synthesis. First, we find that an elevated intracellular CTP concentration or treatment with 3'-deazauridine, a CTPS inhibitor, promotes IMPDH cytoophidium formation and increases the intracellular GTP pool size. Moreover, restriction of cell growth triggers the disassembly of IMPDH cytoophidia, implying that their presence is correlated with active cell metabolism. Finally, we show that the presence of IMPDH cytoophidia in mouse pancreatic islet cells might correlate with nutrient uptake in the animal. Collectively, our findings reveal that formation of IMPDH cytoophidia reflects upregulation of purine nucleotide synthesis, suggesting that the IMPDH cytoophidium plays a role distinct from that of the CTPS cytoophidium in controlling intracellular nucleotide homeostasis.
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Affiliation(s)
- Chia-Chun Chang
- Institute of Biotechnology, National Taiwan University, Taipei 106, Taiwan, Republic of China
| | - Wei-Cheng Lin
- Molecular Medicine Research Center, College of Medicine, Chang Gung University, Tao-Yuan 333, Taiwan, Republic of China
| | - Li-Mei Pai
- Molecular Medicine Research Center, College of Medicine, Chang Gung University, Tao-Yuan 333, Taiwan, Republic of China Graduate Institute of Biomedical Science, College of Medicine, Chang Gung University, Tao-Yuan 333, Taiwan, Republic of China Department of Biochemistry, College of Medicine, Chang Gung University, Tao-Yuan 333, Taiwan, Republic of China
| | - Hsuan-Shu Lee
- Institute of Biotechnology, National Taiwan University, Taipei 106, Taiwan, Republic of China Department of Internal Medicine, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei 10051, Taiwan, Republic of China
| | - Shinn-Chih Wu
- Institute of Biotechnology, National Taiwan University, Taipei 106, Taiwan, Republic of China Department of Animal Science and Technology, National Taiwan University, Taipei 106, Taiwan, Republic of China
| | - Shih-Torng Ding
- Institute of Biotechnology, National Taiwan University, Taipei 106, Taiwan, Republic of China Department of Animal Science and Technology, National Taiwan University, Taipei 106, Taiwan, Republic of China
| | - Ji-Long Liu
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK
| | - Li-Ying Sung
- Institute of Biotechnology, National Taiwan University, Taipei 106, Taiwan, Republic of China Agricultural Biotechnology Research Center, Academia Sinica, Taipei 115, Taiwan, Republic of China
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26
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Tastan ÖY, Liu JL. CTP Synthase Is Required for Optic Lobe Homeostasis in Drosophila. J Genet Genomics 2015; 42:261-74. [PMID: 26059773 PMCID: PMC4458259 DOI: 10.1016/j.jgg.2015.04.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Revised: 04/09/2015] [Accepted: 04/10/2015] [Indexed: 10/31/2022]
Abstract
CTP synthase (CTPsyn) is a metabolic enzyme responsible for the de novo synthesis of the nucleotide CTP. Several recent studies have shown that CTPsyn forms filamentous subcellular structures known as cytoophidia in bacteria, yeast, fruit flies and humans. However, it remains elusive whether and how CTPsyn and cytoophidia play a role during development. Here, we show that cytoophidia are abundant in the neuroepithelial stem cells in Drosophila optic lobes. Optic lobes are underdeveloped in CTPsyn mutants as well as in CTPsyn RNAi. Moreover, overexpressing CTPsyn impairs the development of optic lobes, specifically by blocking the transition from neuroepithelium to neuroblast. Taken together, our results indicate that CTPsyn is critical for optic lobe homeostasis in Drosophila.
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Affiliation(s)
- Ömür Y Tastan
- Medical Research Council Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, United Kingdom
| | - Ji-Long Liu
- Medical Research Council Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, United Kingdom.
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Keppeke GD, Andrade LE, Grieshaber SS, Chan EK. Microinjection of specific anti-IMPDH2 antibodies induces disassembly of cytoplasmic rods/rings that are primarily stationary and stable structures. Cell Biosci. 2015;5:1. [PMID: 25601894 PMCID: PMC4298086 DOI: 10.1186/2045-3701-5-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Accepted: 12/18/2014] [Indexed: 02/08/2023] Open
Abstract
Background Our laboratory previously reported interesting rods 3–10 μm long and rings 2–5 μm diameter (RR) in the cytoplasm of mammalian cells. Experimental evidence show that both inosine-5'-monophosphate dehydrogenase 2 (IMPDH2) and cytidine triphosphate synthetase (CTPS) are components of RR structures. Several cell types, including mouse embryonic stem cells, and cell lines, such as mouse 3 T3 and rat NRK, naturally present RR structures, while other cells can present RR when treated with compounds interfering with GTP/CTP biosynthetic pathways. In this study, we aimed to investigate the dynamic behavior of these RR in live cells. Results RR were detected in >90% of COS-7 and HeLa cells treated with 1 mM ribavirin or 6-Diazo-5-oxo-L-norleucine (DON) for 24 h, and in 75% of COS-7 cells treated with 1 mM mycophenolic acid (MPA) for the same period of time. Microinjection of affinity-purified anti-IMPDH2 antibodies in live COS-7 cells treated with ribavirin, DON, or MPA showed mature forms of RR presented as stable and stationary structures in 71% of cells. In the remaining 29% of cells, RR acquired erratic movement and progressively disassembled into fragments and disappeared within 10 min. The specific stationary state and antibody-dependent disassembling of RR structures was independently confirmed in COS-7 and HeLa cells transfected with GFP-tagged IMPDH2. Conclusions This is the first demonstration of disassembly of RR structures upon microinjection of anti-IMPDH2 antibodies that led to the disappearance of the molecular aggregates. The disassembly of RR after microinjection of anti-IMPDH2 antibody further strengthens the notion that IMPDH2 are major building blocks of RR. Using two independent methods, this study demonstrated that the induced RR are primarily stationary structures in live cells and that IMPDH2 is a key component of RR. Electronic supplementary material The online version of this article (doi:10.1186/2045-3701-5-1) contains supplementary material, which is available to authorized users.
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Abstract
A general view is that Schizosaccharomyces pombe undergoes symmetric cell division with two daughter cells inheriting equal shares of the content from the mother cell. Here we show that CTP synthase, a metabolic enzyme responsible for the de novo synthesis of the nucleotide CTP, can form filamentous cytoophidia in the cytoplasm and nucleus of S. pombe cells. Surprisingly, we observe that both cytoplasmic and nuclear cytoophidia are asymmetrically inherited during cell division. Our time-lapse studies suggest that cytoophidia are dynamic. Once the mother cell divides, the cytoplasmic and nuclear cytoophidia independently partition into one of the two daughter cells. Although the two daughter cells differ from one another morphologically, they possess similar chances of inheriting the cytoplasmic cytoophidium from the mother cell, suggesting that the partition of cytoophidium is a stochastic process. Our findings on asymmetric inheritance of cytoophidia in S. pombe offer an exciting opportunity to study the inheritance of metabolic enzymes in a well-studied model system.
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Affiliation(s)
- Jing Zhang
- MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK
| | - Lydia Hulme
- MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK
| | - Ji-Long Liu
- MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK
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Gou KM, Chang CC, Shen QJ, Sung LY, Liu JL. CTP synthase forms cytoophidia in the cytoplasm and nucleus. Exp Cell Res. 2014;323:242-253. [PMID: 24503052 DOI: 10.1016/j.yexcr.2014.01.029] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Revised: 01/24/2014] [Accepted: 01/26/2014] [Indexed: 02/07/2023]
Abstract
CTP synthase is an essential metabolic enzyme responsible for the de novo synthesis of CTP. Multiple studies have recently showed that CTP synthase protein molecules form filamentous structures termed cytoophidia or CTP synthase filaments in the cytoplasm of eukaryotic cells, as well as in bacteria. Here we report that CTP synthase can form cytoophidia not only in the cytoplasm, but also in the nucleus of eukaryotic cells. Both glutamine deprivation and glutamine analog treatment promote formation of cytoplasmic cytoophidia (C-cytoophidia) and nuclear cytoophidia (N-cytoophidia). N-cytoophidia are generally shorter and thinner than their cytoplasmic counterparts. In mammalian cells, both CTP synthase 1 and CTP synthase 2 can form cytoophidia. Using live imaging, we have observed that both C-cytoophidia and N-cytoophidia undergo multiple rounds of fusion upon glutamine analog treatment. Our study reveals the coexistence of cytoophidia in the cytoplasm and nucleus, therefore providing a good opportunity to investigate the intracellular compartmentation of CTP synthase.
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