Dataset Information

Development of a selective fluorescence-based enzyme assay for glycerophosphodiesterase family members GDE4 and GDE7.

ABSTRACT: Lysophosphatidic acid (LPA) is a lipid mediator that regulates various processes, including cell migration and cancer progression. Autotaxin (ATX) is a lysophospholipase D-type exoenzyme that produces extracellular LPA. In contrast, glycerophosphodiesterase (GDE) family members GDE4 and GDE7 are intracellular lysophospholipases D that form LPA, depending on Mg²⁺ and Ca²⁺, respectively. Since no fluorescent substrate for these GDEs has been reported, in the present study, we examined whether a fluorescent ATX substrate, FS-3, could be applied to study GDE activity. We found that the membrane fractions of human GDE4- and GDE7-overexpressing human embryonic kidney 293T cells hydrolyzed FS-3 in a manner almost exclusively dependent on Mg²⁺ and Ca²⁺, respectively. Using these assay systems, we found that several ATX inhibitors, including α-bromomethylene phosphonate analog of LPA and 3-carbacyclic phosphatidic acid, also potently inhibited GDE4 and GDE7 activities. In contrast, the ATX inhibitor S32826 hardly inhibited these activities. Furthermore, FS-3 was hydrolyzed in a Mg²⁺-dependent manner by the membrane fraction of human prostate cancer LNCaP cells that express GDE4 endogenously but not by those of GDE4-deficient LNCaP cells. Similar Ca²⁺-dependent GDE7 activity was observed in human breast cancer MCF-7 cells but not in GDE7-deficient MCF-7 cells. Finally, our assay system could selectively measure GDE4 and GDE7 activities in a mixture of the membrane fractions of GDE4- and GDE7-overexpressing human embryonic kidney 293T cells in the presence of S32826. These findings allow high-throughput assays of GDE4 and GDE7 activities, which could lead to the development of selective inhibitors and stimulators as well as a better understanding of the biological roles of these enzymes.

SUBMITTER: Kitakaze K

PROVIDER: S-EPMC8591415 | biostudies-literature | 2021

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Development of a selective fluorescence-based enzyme assay for glycerophosphodiesterase family members GDE4 and GDE7.

Kitakaze Keisuke K Tsuboi Kazuhito K Tsuda Maho M Takenouchi Yasuhiro Y Ishimaru Hironobu H Okamoto Yasuo Y

Journal of lipid research 20211018

Lysophosphatidic acid (LPA) is a lipid mediator that regulates various processes, including cell migration and cancer progression. Autotaxin (ATX) is a lysophospholipase D-type exoenzyme that produces extracellular LPA. In contrast, glycerophosphodiesterase (GDE) family members GDE4 and GDE7 are intracellular lysophospholipases D that form LPA, depending on Mg<sup>2+</sup> and Ca<sup>2+</sup>, respectively. Since no fluorescent substrate for these GDEs has been reported, in the present study, we ...[more]

PMID: 34673020

Similar Datasets

Project description:Brevetoxins are a family of ladder-frame polyether toxins produced during blooms of the marine dinoflagellate Karenia brevis. Inhalation of brevetoxins aerosolized by wind and wave action can lead to asthma-like symptoms in beach goers. Consumption of either shellfish or finfish exposed to K. brevis blooms can lead to the development of neurotoxic shellfish poisoning. The toxic effects of brevetoxins are due to activation of voltage-sensitive sodium channels (VSSCs) in cell membranes. Binding of brevetoxin analogs and competitors to site 5 on these channels has historically been measured using a radioligand competition assay that is fraught with difficulty, including slow analysis time, production of radioactive waste, and cumbersome and expensive methods associated with the generation of radioactive labeled ligands. In this study, we describe the development of a novel fluorescent synaptosome binding assay for the brevetoxin receptor. BODIPY(®)-conjugated to PbTx-2 was used as the labeled ligand. The BODIPY(®)-PbTx-2 conjugate was found to displace [(3)H]-PbTx-3 from its binding site on VSSCs on rat brain synaptosomes with an equilibrium inhibition constant of 0.11 nM. We have shown that brevetoxin A and B analogs are all able to compete for binding with the fluorescent ligand. Most importantly, this assay was validated against the current site 5 receptor binding assay standard, the radioligand receptor assay for the brevetoxin receptor using [(3)H]-PbTx-3 as the labeled ligand. The fluorescence based assay yielded equilibrium inhibition constants comparable to the radioligand assay for all brevetoxin analogs. The fluorescence based assay was quicker, far less expensive, and did not generate radioactive waste or need radioactive facilities. As such, this fluorescence-based assay can be used to replace the current radioligand assay for site 5 on voltage-sensitive sodium channels and will be a vital tool for future experiments examining the binding affinity of various ligands for site 5 on sodium channels.

Project description:In late 2019, a human coronavirus, now known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), emerged, likely from a zoonotic reservoir. This virus causes COVID-19, has infected millions of people, and has led to hundreds of thousands of deaths across the globe. While the best interventions to control and ultimately stop the pandemic are prophylactic vaccines, antiviral therapeutics are important to limit morbidity and mortality in those already infected. At this time, only one FDA-approved anti-SARS-CoV-2 antiviral drug, remdesivir, is available, and unfortunately, its efficacy appears to be limited. Thus, the identification of new and efficacious antivirals is of the highest importance. In order to facilitate rapid drug discovery, flexible, sensitive, and high-throughput screening methods are required. With respect to drug targets, most attention is focused on either the viral RNA-dependent RNA polymerase or the main viral protease, 3CLpro 3CLpro is an attractive target for antiviral therapeutics, as it is essential for processing newly translated viral proteins and the viral life cycle cannot be completed without protease activity. In this work, we report a new assay to identify inhibitors of 3CLpro Our reporter is based on a green fluorescent protein (GFP)-derived protein that fluoresces only after cleavage by 3CLpro This experimentally optimized reporter assay allows for antiviral drug screening in human cell culture at biosafety level 2 (BSL2) with high-throughput compatible protocols. Using this screening approach in combination with existing drug libraries may lead to the rapid identification of novel antivirals to suppress SARS-CoV-2 replication and spread.IMPORTANCE The COVID-19 pandemic has already led to more than 700,000 deaths and innumerable changes to daily life worldwide. Along with development of a vaccine, identification of effective antivirals to treat infected patients is of the highest importance. However, rapid drug discovery requires efficient methods to identify novel compounds that can inhibit the virus. In this work, we present a method for identifying inhibitors of the SARS-CoV-2 main protease, 3CLpro This reporter-based assay allows for antiviral drug screening in human cell culture at biosafety level 2 (BSL2) with high-throughput compatible sample processing and analysis. This assay may help identify novel antivirals to control the COVID-19 pandemic.

Dataset Information

Development of a selective fluorescence-based enzyme assay for glycerophosphodiesterase family members GDE4 and GDE7.

Publications

Development of a selective fluorescence-based enzyme assay for glycerophosphodiesterase family members GDE4 and GDE7.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets