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Microbiology (Reading, England) Dec 2020Nudix proteins catalyse hydrolysis of pyrophosphate bonds in a variety of substrates and are ubiquitous in all domains of life. Their widespread presence and broad... (Review)
Review
Nudix proteins catalyse hydrolysis of pyrophosphate bonds in a variety of substrates and are ubiquitous in all domains of life. Their widespread presence and broad substrate specificity suggest that they have important cellular functions. In this review, we summarize the state of knowledge on microbial Nudix proteins involved in pathogenesis.
Topics: Amino Acid Sequence; Bacterial Proteins; Diphosphates; Pyrophosphatases; Sequence Alignment; Viral Proteins; Virulence; Virulence Factors; Nudix Hydrolases
PubMed: 33253082
DOI: 10.1099/mic.0.000993 -
Molecules (Basel, Switzerland) Apr 2021Inorganic pyrophosphatase (PPase) is a ubiquitous enzyme that converts pyrophosphate (PP) to phosphate and, in this way, controls numerous biosynthetic reactions that... (Review)
Review
Inorganic pyrophosphatase (PPase) is a ubiquitous enzyme that converts pyrophosphate (PP) to phosphate and, in this way, controls numerous biosynthetic reactions that produce PP as a byproduct. PPase activity is generally assayed by measuring the product of the hydrolysis reaction, phosphate. This reaction is reversible, allowing PP synthesis measurements and making PPase an excellent model enzyme for the study of phosphoanhydride bond formation. Here we summarize our long-time experience in measuring PPase activity and overview three types of the assay that are found most useful for (a) low-substrate continuous monitoring of PP hydrolysis, (b) continuous and fixed-time measurements of PP synthesis, and (c) high-throughput procedure for screening purposes. The assays are based on the color reactions between phosphomolybdic acid and triphenylmethane dyes or use a coupled ATP sulfurylase/luciferase enzyme assay. We also provide procedures to estimate initial velocity from the product formation curve and calculate the assay medium's composition, whose components are involved in multiple equilibria.
Topics: Diphosphates; Enzyme Assays; Humans; Hydrolysis; Inorganic Pyrophosphatase; Luciferases; Phosphates
PubMed: 33919593
DOI: 10.3390/molecules26082356 -
Microbiology (Reading, England) Dec 2020
Topics: Bacillus; Biological Control Agents; COVID-19; Genetic Techniques; Humans; Microbiology; Molecular Imaging; Periodicals as Topic; Pyrophosphatases; SARS-CoV-2; Vibrio; Nudix Hydrolases
PubMed: 33353584
DOI: 10.1099/mic.0.001019 -
European Journal of Medicinal Chemistry Mar 2024The cancer immunotherapies involved in cGAS-STING pathway have been made great progress in recent years. STING agonists exhibit broad-spectrum anti-tumor effects with... (Review)
Review
The cancer immunotherapies involved in cGAS-STING pathway have been made great progress in recent years. STING agonists exhibit broad-spectrum anti-tumor effects with strong immune response. As a negative regulator of the cGAS-STING pathway, ecto-nucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) can hydrolyze extracellular 2', 3'-cGAMP and reduce extracellular 2', 3'-cGAMP concentration. ENPP1 has been validated to play important roles in diabetes, cancers, and cardiovascular disease and now become a promising target for tumor immunotherapy. Several ENPP1 inhibitors under development have shown good anti-tumor effects alone or in combination with other agents in clinical and preclinical researches. In this review, the biological profiles of ENPP1 were described, and the structures and the structure-activity relationships (SAR) of the known ENPP1 inhibitors were summarized. This review also provided the prospects and challenges in the development of ENPP1 inhibitors.
Topics: Humans; Phosphoric Diester Hydrolases; Neoplasms; Nucleotidyltransferases; Immunotherapy; Pyrophosphatases
PubMed: 38359537
DOI: 10.1016/j.ejmech.2024.116211 -
The Biochemical Journal Apr 2021In the conditions of [Mg2+] elevation that occur, in particular, under low oxygen stress and are the consequence of the decrease in [ATP] and increase in [ADP] and... (Review)
Review
In the conditions of [Mg2+] elevation that occur, in particular, under low oxygen stress and are the consequence of the decrease in [ATP] and increase in [ADP] and [AMP], pyrophosphate (PPi) can function as an alternative energy currency in plant cells. In addition to its production by various metabolic pathways, PPi can be synthesized in the combined reactions of pyruvate, phosphate dikinase (PPDK) and pyruvate kinase (PK) by so-called PK/PPDK substrate cycle, and in the reverse reaction of membrane-bound H+-pyrophosphatase, which uses the energy of electrochemical gradients generated on tonoplast and plasma membrane. The PPi can then be consumed in its active forms of MgPPi and Mg2PPi by PPi-utilizing enzymes, which require an elevated [Mg2+]. This ensures a continuous operation of glycolysis in the conditions of suppressed ATP synthesis, keeping metabolism energy efficient and less dependent on ATP.
Topics: Adenosine Diphosphate; Adenosine Monophosphate; Adenosine Triphosphate; Cell Membrane; Diphosphates; Energy Metabolism; Gene Expression Regulation, Plant; Intracellular Membranes; Magnesium; Plant Cells; Plant Proteins; Plants; Pyrophosphatases; Pyruvate Kinase; Pyruvate, Orthophosphate Dikinase
PubMed: 33881486
DOI: 10.1042/BCJ20200940 -
International Journal of Molecular... Apr 2021Pathological (ectopic) mineralization of soft tissues occurs during aging, in several common conditions such as diabetes, hypercholesterolemia, and renal failure and in... (Review)
Review
Pathological (ectopic) mineralization of soft tissues occurs during aging, in several common conditions such as diabetes, hypercholesterolemia, and renal failure and in certain genetic disorders. Pseudoxanthoma elasticum (PXE), a multi-organ disease affecting dermal, ocular, and cardiovascular tissues, is a model for ectopic mineralization disorders. ABCC6 dysfunction is the primary cause of PXE, but also some cases of generalized arterial calcification of infancy (GACI). ABCC6 deficiency in mice underlies an inducible dystrophic cardiac calcification phenotype (DCC). These calcification diseases are part of a spectrum of mineralization disorders that also includes Calcification of Joints and Arteries (CALJA). Since the identification of ABCC6 as the "PXE gene" and the development of several animal models (mice, rat, and zebrafish), there has been significant progress in our understanding of the molecular genetics, the clinical phenotypes, and pathogenesis of these diseases, which share similarities with more common conditions with abnormal calcification. ABCC6 facilitates the cellular efflux of ATP, which is rapidly converted into inorganic pyrophosphate (PPi) and adenosine by the ectonucleotidases NPP1 and CD73 (NT5E). PPi is a potent endogenous inhibitor of calcification, whereas adenosine indirectly contributes to calcification inhibition by suppressing the synthesis of tissue non-specific alkaline phosphatase (TNAP). At present, therapies only exist to alleviate symptoms for both PXE and GACI; however, extensive studies have resulted in several novel approaches to treating PXE and GACI. This review seeks to summarize the role of ABCC6 in ectopic calcification in PXE and other calcification disorders, and discuss therapeutic strategies targeting various proteins in the pathway (ABCC6, NPP1, and TNAP) and direct inhibition of calcification via supplementation by various compounds.
Topics: 5'-Nucleotidase; ATP-Binding Cassette Transporters; Animals; Calcification, Physiologic; Calcinosis; Diphosphates; GPI-Linked Proteins; Humans; Joint Diseases; Mice; Multidrug Resistance-Associated Proteins; Phosphoric Diester Hydrolases; Pseudoxanthoma Elasticum; Pyrophosphatases; Rats; Vascular Calcification; Vascular Diseases
PubMed: 33925341
DOI: 10.3390/ijms22094555 -
The Journal of Clinical Investigation Jan 2022Various populations of cells are recruited to the heart after cardiac injury, but little is known about whether cardiomyocytes directly regulate heart repair. Using a...
Various populations of cells are recruited to the heart after cardiac injury, but little is known about whether cardiomyocytes directly regulate heart repair. Using a murine model of ischemic cardiac injury, we demonstrate that cardiomyocytes play a pivotal role in heart repair by regulating nucleotide metabolism and fates of nonmyocytes. Cardiac injury induced the expression of the ectonucleotidase ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1), which hydrolyzes extracellular ATP to form AMP. In response to AMP, cardiomyocytes released adenine and specific ribonucleosides that disrupted pyrimidine biosynthesis at the orotidine monophosphate (OMP) synthesis step and induced genotoxic stress and p53-mediated cell death of cycling nonmyocytes. As nonmyocytes are critical for heart repair, we showed that rescue of pyrimidine biosynthesis by administration of uridine or by genetic targeting of the ENPP1/AMP pathway enhanced repair after cardiac injury. We identified ENPP1 inhibitors using small molecule screening and showed that systemic administration of an ENPP1 inhibitor after heart injury rescued pyrimidine biosynthesis in nonmyocyte cells and augmented cardiac repair and postinfarct heart function. These observations demonstrate that the cardiac muscle cell regulates pyrimidine metabolism in nonmuscle cells by releasing adenine and specific nucleosides after heart injury and provide insight into how intercellular regulation of pyrimidine biosynthesis can be targeted and monitored for augmenting tissue repair.
Topics: Adenosine Monophosphate; Adenosine Triphosphate; Animals; Heart Injuries; Mice; Myocardium; Myocytes, Cardiac; Phosphoric Diester Hydrolases; Pyrimidines; Pyrophosphatases; Regeneration; Signal Transduction
PubMed: 34813507
DOI: 10.1172/JCI149711 -
Nature Metabolism Mar 2020Critical to the bacterial stringent response is the rapid relocation of resources from proliferation toward stress survival through the respective accumulation and...
Critical to the bacterial stringent response is the rapid relocation of resources from proliferation toward stress survival through the respective accumulation and degradation of (p)ppGpp by RelA and SpoT homologues. While mammalian genomes encode MESH1, a homologue of the bacterial (p)ppGpp hydrolase SpoT, neither (p)ppGpp nor its synthetase has been identified in mammalian cells. Here, we show that human MESH1 is an efficient cytosolic NADPH phosphatase that facilitates ferroptosis. Visualization of the MESH1-NADPH crystal structure revealed a bona fide affinity for the NADPH substrate. Ferroptosis-inducing erastin or cystine deprivation elevates MESH1, whose overexpression depletes NADPH and sensitizes cells to ferroptosis, whereas MESH1 depletion promotes ferroptosis survival by sustaining the levels of NADPH and GSH and by reducing lipid peroxidation. The ferroptotic protection by MESH1 depletion is ablated by suppression of the cytosolic NAD(H) kinase, NADK, but not its mitochondrial counterpart NADK2. Collectively, these data shed light on the importance of cytosolic NADPH levels and their regulation under ferroptosis-inducing conditions in mammalian cells.
Topics: Cytosol; Ferroptosis; Humans; NADP; Pyrophosphatases
PubMed: 32462112
DOI: 10.1038/s42255-020-0181-1 -
Frontiers in Immunology 2023Ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) is a type II transmembrane glycoprotein expressed in many tissues. High expression levels of ENPP1 have been...
Ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) is a type II transmembrane glycoprotein expressed in many tissues. High expression levels of ENPP1 have been observed in many cancer types such as lung cancer, ovarian cancer, and breast cancer. Such overexpression has been associated with poor prognosis in these diseases. Hence, ENPP1 is a potential target for immunotherapy across multiple cancers. Here, we isolated and characterized two high-affinity and specific anti-ENPP1 Fab antibody candidates, 17 and 3G12, from large phage-displayed human Fab libraries. After conversion to IgG1, the binding of both antibodies increased significantly due to avidity effects. Based on these antibodies, we generated antibody-drug conjugates (ADCs), IgG-based bispecific T-cell engagers (IbTEs), and CAR T-cells which all exhibited potent killing of ENPP1-expressing cells. Thus, these various antibody-derived modalities are promising therapeutic candidates for cancers expressing human ENPP1.
Topics: Humans; Female; Phosphoric Diester Hydrolases; Immunoconjugates; Breast Neoplasms; Immunoglobulin G; Pyrophosphatases
PubMed: 36761762
DOI: 10.3389/fimmu.2023.1070492 -
Annual Review of Pathology Jan 2024The enzyme ectonucleotide pyrophosphatase/phosphodiesterase 1 () codes for a type 2 transmembrane glycoprotein that hydrolyzes extracellular ATP to generate... (Review)
Review
The enzyme ectonucleotide pyrophosphatase/phosphodiesterase 1 () codes for a type 2 transmembrane glycoprotein that hydrolyzes extracellular ATP to generate pyrophosphate (PP) and adenosine monophosphate, thereby contributing to downstream purinergic signaling pathways. The clinical phenotypes induced by ENPP1 deficiency are seemingly contradictory and include early-onset osteoporosis in middle-aged adults and life-threatening vascular calcifications in the large arteries of infants with generalized arterial calcification of infancy. The progressive overmineralization of soft tissue and concurrent undermineralization of skeleton also occur in the general medical population, where it is referred to as paradoxical mineralization to highlight the confusing pathophysiology. This review summarizes the clinical presentation and pathophysiology of paradoxical mineralization unveiled by ENPP1 deficiency and the bench-to-bedside development of a novel ENPP1 biologics designed to treat mineralization disorders in the rare disease and general medical population.
Topics: Adult; Humans; Middle Aged; Phosphoric Diester Hydrolases; Vascular Calcification; Pyrophosphatases
PubMed: 37871131
DOI: 10.1146/annurev-pathmechdis-051222-121126