A non-radiochemical assay procedure for CTP synthetase was developed in which CTP is detected at 280 nm after separation with anion-exchange HPLC. A complete separation of all nucleoside triphosphates was achieved within 11 min and the minimum amount of CTP which could be accurately determined proved to be 5 pmol. Therefore, our assay procedure is ten-fold more sensitive compared to the frequently used radiochemical assays. The assay was linear with time and protein concentration, although at low protein concentration a lag phase was observed. An amount of 2 x 10(6) cells was already sufficient to determine the specific activity of CTP synthetase in HL-60 cells, lymphocytes and in lymphoblasts obtained from pediatric patients suffering from acute lymphoblastic leukemia.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/s0378-4347(97)00060-1 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Cytoophidium complexes resonate with cell fates.
Cell Mol Life Sci
January 2025
School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China.
Metabolism is a fundamental characteristic of life. In 2010, we discovered that the metabolic enzyme CTP synthase (CTPS) can assemble a snake like structure inside cells, which we call the cytoophidium. Including CTPS, an increasing number of metabolic enzymes have been found to form cytoophidia in cells.
View Article and Find Full Text PDFPyrimidine synthesis enzyme CTP synthetase 1 suppresses antiviral interferon induction by deamidating IRF3.
Immunity
January 2025
Section of Infection and Immunity, Herman Ostrow School of Dentistry, Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, CA 90089, USA. Electronic address:
Metabolism is typically contextualized in conjunction with proliferation and growth. The roles of metabolic enzymes beyond metabolism-such as in innate immune responses-are underexplored. Using a focused short hairpin RNA (shRNA)-mediated screen, we identified CTP synthetase 1 (CTPS1), a rate-limiting enzyme of pyrimidine synthesis, as a negative regulator of interferon induction.
View Article and Find Full Text PDFDifferential Cytoophidium Assembly between and .
Int J Mol Sci
September 2024
School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China.
The de novo synthesis of cytidine 5'-triphosphate (CTP) is catalyzed by the enzyme CTP synthase (CTPS), which is known to form cytoophidia across all three domains of life. In this study, we use the budding yeast and the fission yeast as model organisms to compare cytoophidium assembly under external environmental and intracellular CTPS alterations. We observe that under low and high temperature conditions, cytoophidia in fission yeast gradually disassemble, while cytoophidia in budding yeast remain unaffected.
View Article and Find Full Text PDFThe Impact of Developmental and Metabolic Cues on Cytoophidium Formation.
Int J Mol Sci
September 2024
School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China.
The cytoophidium, composed mainly of CTP synthase (CTPS), is a newly discovered dynamic filamentous structure in various organisms such as archaea, bacteria, and humans. These filamentous structures represent a fascinating example of intracellular compartmentation and dynamic regulation of metabolic enzymes. Currently, cytoophidia have been proven to be tightly regulated and highly dynamic, responding rapidly to developmental and metabolic cues and playing a critical role in maintaining cellular homeostasis.
View Article and Find Full Text PDFArchitecture of CTPS filament networks revealed by cryo-electron tomography.
Exp Cell Res
October 2024
School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China; Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, UK. Electronic address:
The cytoophidium is a novel type of membraneless organelle, first observed in the ovaries of Drosophila using fluorescence microscopy. In vitro, purified Drosophila melanogaster CTPS (dmCTPS) can form metabolic filaments under the presence of either substrates or products, and their structures that have been analyzed using cryo-electron microscopy (cryo-EM). These dmCTPS filaments are considered the fundamental units of cytoophidia.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!