title: CTP synthase forms cytoophidia in the cytoplasm and nucleus.
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.
authors: MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK; State Key Laboratory for Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, PR China.
authors: Ke-Mian
authors: KM
authors: Gou
authors: Institute of Biotechnology, National Taiwan University, Taipei, Taiwan, ROC.
authors: Chia-Chun
authors: CC
authors: Chang
authors: MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK.
authors: Qing-Ji
authors: QJ
authors: Shen
authors: Institute of Biotechnology, National Taiwan University, Taipei, Taiwan, ROC; Agricultural Biotechnology Research Center, Academia Sinica, Taipei 115, Taiwan, ROC. Electronic address: liyingsung@ntu.edu.tw.
authors: Li-Ying
authors: LY
authors: Sung
authors: MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK. Electronic address: jilong.liu@dpag.ox.ac.uk.
authors: Ji-Long
authors: JL
authors: Liu
mesh_terms: D016475:3T3 Cells; D000818:Animals; D019731:Carbon-Nitrogen Ligases / Q000378:metabolism*; D002460:Cell Line; D002467:Cell Nucleus / Q000201:enzymology*; D003593:Cytoplasm / Q000201:enzymology*; D003599:Cytoskeleton / Q000201:enzymology; D005973:Glutamine / Q000031:analogs & derivatives / Q000172:deficiency / Q000378:metabolism; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D051379:Mice
chemical_list: D005973:Glutamine; D019731:Carbon-Nitrogen Ligases; C019951:CTP synthetase
keywords: CTP synthase; Cytoophidium; Intracellular compartment