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In EGFR-mutant lung cancer, drug-tolerant persister cells (DTPCs) show prolonged survival when receiving EGFR tyrosine kinase inhibitor (TKI) treatments. They are a likely source of drug resistance, but little is known about how these cells tolerate drugs. Ribonucleic acids (RNAs) molecules control cell growth and stress responses. Nucleic acid metabolism provides metabolites, such as purines, supporting RNA synthesis and downstream functions. Recently, noncoding RNAs (ncRNAs), such as microRNAs (miRNAs), have received attention due to their capacity to repress gene expression via inhibitory binding to downstream messenger RNAs (mRNAs). Here, our study links miRNA expression to purine metabolism and drug tolerance. MiR-21-5p (guide strand) is a commonly upregulated miRNA in disease states, including cancer and drug resistance. However, the expression and function of miR-21-3p (passenger strand) are not well understood. We found that upregulation of miR-21-5p and miR-21-3p tune purine metabolism leading to increased drug tolerance. Metabolomics data demonstrated that purine metabolism was the top pathway in the DTPCs compared with the parental cells. The changes in purine metabolites in the DTPCs were partially rescued by targeting miR-21. Analysis of protein levels in the DTPCs showed that reduced expression of adenylosuccinate lyase (ADSL) was reversed after the miR-21 knockdown. ADSL is an essential enzyme in the de novo purine biosynthesis pathway by converting succino-5-aminoimidazole-4-carboxamide riboside (succino-AICAR or SAICAR) to AICAR (or acadesine) as well as adenylosuccinate to adenosine monophosphate (AMP). In the DTPCs, miR-21-5p and miR-21-3p repress ADSL expression. The levels of top decreased metabolite in the DTPCs, AICAR was reversed when miR-21 was blocked. AICAR induced oxidative stress, evidenced by increased reactive oxygen species (ROS) and reduced expression of nuclear factor erythroid-2-related factor 2 (NRF2). Concurrently, miR-21 knockdown induced ROS generation. Therapeutically, a combination of AICAR and osimertinib increased ROS levels and decreased osimertinib-induced NRF2 expression. In a MIR21 knockout mouse model, MIR21 loss-of-function led to increased purine metabolites but reduced ROS scavenging capacity in lung tissues in physiological conditions. Our data has established a link between ncRNAs, purine metabolism, and the redox imbalance pathway. This discovery will increase knowledge of the complexity of the regulatory RNA network and potentially enable novel therapeutic options for drug-resistant patients.

Adenylosuccinase deficiency is a rare inborn error of metabolism. We present a newborn who died at 52 days of age with clinical features suggestive of severe epileptic encephalopathy and leukodystrophy of unknown cause. Post-mortem examination showed an unusual vacuolar appearance of the brain. A molecular autopsy performed via singleton clinical exome analysis revealed a known pathogenic and a variant of uncertain significance in ADSL that encodes adenylosuccinase. Tests on previously stored plasma samples showed elevated succinyladenosine and succinylaminoimidazole carboxamide riboside levels. Adenylosuccinase activity in stored fibroblasts was only similar to 5% of control confirming the diagnosis of adenylosuccinase deficiency in the child. The parents opted for a chorionic villus biopsy in a subsequent pregnancy and had a child unaffected by adenylosuccinase deficiency. This report adds vacuolating leukodystrophy as a novel feature of adenylosuccinase deficiency and shows the power of biochemical investigations directed by genomic studies to achieve accurate diagnosis. Importantly, this case demonstrates the importance of anticipatory banking of biological samples for reverse biochemical phenotyping in individuals with undiagnosed disorders who may not survive.

Background and aims Hepatocellular carcinoma (HCC) is among the most common cancer types worldwide, yet patients with HCC have limited treatment options. There is an urgent need to identify drug targets that specifically inhibit the growth of HCC cells. Approach and results We used a CRISPR library targeting ~2,000 druggable genes to perform a high-throughput screen and identified adenylosuccinate lyase (ADSL), a key enzyme involved in the de novo purine synthesis pathway, as a potential drug target for HCC. ADSL has been implicated as a potential oncogenic driver in some cancers, but its role in liver cancer progression remains unknown. CRISPR-mediated knockout of ADSL impaired colony formation of liver cancer cells by affecting AMP production. In the absence of ADSL, the growth of liver tumors is retarded in vivo. Mechanistically, we found that ADSL knockout caused S-phase cell cycle arrest not by inducing DNA damage but by impairing mitochondrial function. Using data from patients with HCC, we also revealed that high ADSL expression occurs during tumorigenesis and is linked to poor survival rate. Conclusions Our findings uncover the role of ADSL-mediated de novo purine synthesis in fueling mitochondrial ATP production to promote liver cancer cell growth. Targeting ADSL may be a therapeutic approach for patients with HCC.

Adenylosuccinate lyase (ADSL) functions in de novo purine synthesis (DNPS) and the purine nucleotide cycle. ADSL deficiency (ADSLD) causes numerous neurodevelopmental pathologies, including microcephaly and autism spectrum disorder. ADSLD patients have normal serum purine nucleotide levels but exhibit accumulation of dephosphorylated ADSL substrates, S-Ado, and SAICAr, the latter being implicated in neurotoxic effects through unknown mechanisms. We examined the phenotypic effects of ADSL depletion in human cells and their relation to phenotypic outcomes. Using specific interventions to compensate for reduced purine levels or modulate SAICAr accumulation, we found that diminished AMP levels resulted in increased DNA damage signaling and cell cycle delays, while primary ciliogenesis was impaired specifically by loss of ADSL or administration of SAICAr. ADSL-deficient chicken and zebrafish embryos displayed impaired neurogenesis and microcephaly. Neuroprogenitor attrition in zebrafish embryos was rescued by pharmacological inhibition of DNPS, but not increased nucleotide concentration. Zebrafish also displayed phenotypes commonly linked to ciliopathies. Our results suggest that both reduced purine levels and impaired DNPS contribute to neurodevelopmental pathology in ADSLD and that defective ciliogenesis may influence the ADSLD phenotypic spectrum., ID was funded by the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement no. 754510, THS, JL, and SP were funded by the Ministry of Science, Innovation and Universities (MCIU; PGC2018-095616-B-I00 to THS, PGC2018-099562-B-I00 to JL, and BFU2017-83562-P to SP), the 2017 SGR 1089 (AGAUR), FEDER, the Centres of Excellence Severo Ochoa award, and the CERCA Programme. THS was supported by the NIH Intramural Research Program, National Cancer Institute, Center for Cancer Research. MP was funded by grants from the Deutsche Forschungsgemeinschaft (DFG PH144/4-1 and PH144/6-1). MZ, OS, and VS were supported by Charles University, program PROGRES Q26/LF1. We would like to thank Biocev, First Faculty of Medicine, Charles University, for the opportunity to use their department’s equipment.

Purines are essential molecules that are components of vital biomolecules, such as nucleic acids, coenzymes, signaling molecules, as well as energy transfer molecules. The de novo biosynthesis pathway starts from phosphoribosylpyrophosphate (PRPP) and eventually leads to the synthesis of inosine monophosphate (IMP) by means of 10 sequential steps catalyzed by six different enzymes, three of which are bi-or tri-functional in nature. IMP is then converted into guanosine monophosphate (GMP) or adenosine monophosphate (AMP), which are further phosphorylated into nucleoside di- or tri-phosphates, such as GDP, GTP, ADP and ATP. This review provides an overview of inborn errors of metabolism pertaining to purine synthesis in humans, including either phosphoribosylpyrophosphate synthetase (PRS) overactivity or deficiency, as well as adenylosuccinate lyase (ADSL), 5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase/IMP cyclohydrolase (ATIC), phosphoribosylaminoimidazole succinocarboxamide synthetase (PAICS), and adenylosuccinate synthetase (ADSS) deficiencies. ITPase deficiency is being described as well. The clinical spectrum of these disorders is broad, including neurological impairment, such as psychomotor retardation, epilepsy, hypotonia, or microcephaly; sensory involvement, such as deafness and visual disturbances; multiple malformations, as well as muscle presentations or consequences of hyperuricemia, such as gouty arthritis or kidney stones. Clinical signs are often nonspecific and, thus, overlooked. It is to be hoped that this is likely to be gradually overcome by using sensitive biochemical investigations and next-generation sequencing technologies.

Background Prostate cancer (PCa) is still a serious male malignant disease across the world. However, no exact pathogenesis had been explained. Although adenylosuccinate lyase (ADSL) gene was identified to be important in PCa early in 1987, its comprehensive functions for PCa have not been presented. Methods The cBioPortal for Cancer Genomics, Oncomine and GEO database were retrieved to investigate the associations between of the ADSL gene and PCa. Then, the PC-3, DU145 and C4-2B cell lines were applied in vitro experiments. RNA sequencing and further western blot (WB) were applied to explore the potential mechanisms of ADSL gene in PCa. Results Based on PCa clinical datasets, we firstly found ADSL gene highly expressed in PCa tissues. Moreover, its transcript level increased in the metastatic PCa further. Elevated ADSL gene expression indicated a poor prognosis of PCa. While inhibiting the expression of ADSL with siRNA, the ability of cell proliferation and migration all declined markedly, with increased cell apoptosis inversely. Most of cells were blocked in the G0/G1 phase. Additionally, RNA sequencing also discovered the inactivity of cell cycle pathway after ADSL knockdown, which had also confirmed on the proteins levels. Conclusions Our study identified the ADSL as an oncogene of PCa through regulating the cell cycle pathway firstly, with explicit cell and clinical phenotypes. Further mechanisms were needed to confirm its carcinogenic effect.

Hepatocellular carcinoma (HCC) is among the most common cancer types worldwide; yet, patients with HCC have limited treatment options. There is an urgent need to identify new drug targets that specifically inhibit the growth of HCC cells. Here, we used a newly-engineered CRISPR library targeting ~2,000 druggable genes to perform a high throughput screen, and identified adenylosuccinate lyase (ADSL) – a key enzyme involved in the de novo purine synthesis pathway – as a potential drug target for HCC. ADSL has been implicated as a potential oncogenic driver in some cancers, but its role in liver cancer progression remains unknown. CRISPR-mediated knockout of ADSL impaired colony formation of liver cancer cells by affecting adenosine monophosphate (AMP) production. In the absence of ADSL, the growth of liver tumors is retarded in vivo. Mechanistically, we found that ADSL knockout caused S-phase cell cycle arrest, not by inducing DNA damage, but by impairing mitochondrial function. Using HCC patient data, we also revealed that high ADSL expression occurs during tumorigenesis and is linked to poor survival rate. In conclusion, our findings uncover the role of ADSL-mediated de novo purine synthesis in fueling mitochondrial ATP production to promote liver cancer cell growth. Targeting ADSL may be a therapeutic approach for HCC patients.

Adenylosuccinate lyase deficiency is a rare inherited disorder of purine metabolism causing severe neurological impairment ranging from early-onset neonatal epileptic encephalopathy to progressive psychomotor retardation and autism in later life. Diagnostic workup involves the measurement of toxic succinyl purines in body fluids and gene sequencing. The authors describe a 13-mo-old girl with compound heterozygous variants in the ADSL gene, presenting as early-onset seizures, severe neurological impairment, development delay, and hypotonia. Neuroimaging revealed cerebral atrophy, delayed myelination and diffusion restriction in bilateral basal ganglia, thalamus and periventricular white matter. The present case highlights ADSL deficiency as a rare cause of metabolic epilepsy that needs timely recognition and prevention of unnecessary investigations.

Consumer preference for slow-growing broiler chickens is rising because of increased demand for high-quality poultry products. Korat chicken (KRC) is a slow-growing chicken generated in Thailand. A goal of the KRC breeding program is to produce meat with a low purine content to benefit an aging population, without interfering with growth performance. Thus, this study aimed to investigate the effects of genes encoding melanocortin 4 receptor (MC4R), calpain 1 (CAPN1), and adenylosuccinate lyase (ADSL) on body weight, muscle fiber, and content of purine and its derivatives (i.e., adenine, guanine, hypoxanthine, and xanthine), to develop molecular markers for breeding programs. Genotypes of MC4R, CAPN1, and ADSL were obtained from 583 KRCs by PCR-single-strand conformation polymorphism. The body weight and purine contents of the KRCs were measured every 2 wk until the KRCs reached market weight at 10 wk of age. A significant association between the MC4R genotype and body weight at 2, 4, and 10 wk of age was detected. KRC possessing the BB genotype of CAPN1 showed significantly heavier body weight at 6 wk of age and guanine content at 4 wk of age, and a smaller muscle fiber diameter in the breast muscle at 10 wk of age, compared with those of the other genotypes. In addition, high expression levels of the CAPN1 and ADSL genes were detected in the breast muscle at 2 wk of age. Although higher purine contents were detected at a young age, no significant associations with the MC4R, CAPN1, and ADSL genes were detected. Our results indicate that MC4R and CAPN1 could be used as genetic markers for growth and meat quality in the slow-growing chicken breeding program.

Purines represent a class of essential metabolites produced by the cell to maintain cellular homeostasis and facilitate cell proliferation. In times of high purine demand, the de novo purine biosynthetic pathway is activated; however, the mechanisms that facilitate this process are largely unknown. One plausible mechanism is through intracellular signaling, which results in enzymes within the pathway becoming post-translationally modified to enhance their individual enzyme activities and the overall pathway metabolic flux. Here, we employ a proteomic strategy to investigate the extent to which de novo purine biosynthetic pathway enzymes are post-translationally modified in 293T cells. We identified 7 post-translational modifications on 135 residues across the 6 human pathway enzymes. We further asked whether there were differences in the post-translational modification state of each pathway enzyme isolated from cells cultured in the presence or absence of purines. Of the 174 assigned modifications, 67% of them were only detected in one experimental growth condition in which a significant number of serine and threonine phosphorylations were noted. A survey of the most-probable kinases responsible for these phosphorylation events uncovered a likely AKT phosphorylation site at residue Thr397 of PPAT, which was only detected in cells under purine-supplemented growth conditions. These data suggest that this modification might alter enzyme activity or modulate its interaction(s) with downstream pathway enzymes. Together, these findings propose a role for post-translational modifications in pathway regulation and activation to meet intracellular purine demand.

Increasing evidence suggests that the autism spectrum disorder (ASD) may be associated with inborn errors of metabolism, such as disorders of amino acid metabolism and transport [phenylketonuria, homocystinuria, S-adenosylhomocysteine hydrolase deficiency, branched-chain α-keto acid dehydrogenase kinase deficiency, urea cycle disorders (UCD), Hartnup disease], organic acidurias (propionic aciduria, L-2 hydroxyglutaric aciduria), cholesterol biosynthesis defects (Smith-Lemli-Opitz syndrome), mitochondrial disorders (mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes—MELAS syndrome), neurotransmitter disorders (succinic semialdehyde dehydrogenase deficiency), disorders of purine metabolism [adenylosuccinate lyase (ADSL) deficiency, Lesch-Nyhan syndrome], cerebral creatine deficiency syndromes (CCDSs), disorders of folate transport and metabolism (cerebral folate deficiency, methylenetetrahydrofolate reductase deficiency), lysosomal storage disorders [Sanfilippo syndrome, neuronal ceroid lipofuscinoses (NCL), Niemann-Pick disease type C], cerebrotendinous xanthomatosis (CTX), disorders of copper metabolism (Wilson disease), disorders of haem biosynthesis [acute intermittent porphyria (AIP)] and brain iron accumulation diseases. In this review, we briefly describe etiology, clinical presentation, and therapeutic principles, if they exist, for these conditions. Additionally, we suggest the primary and elective laboratory work-up for their successful early diagnosis.

Background Adenylosuccinate lyase deficiency (ADSLD) is an ultrarare neurometabolic recessive disorder caused by loss-of-function mutations in the ADSL gene. The disease is characterized by wide clinical variability. Here we provide an updated clinical profiling of the disorder and discuss genotype–phenotype correlations. Results Data were collected through "Our Journey with ADSL deficiency Association" by using a dedicated web survey filled-in by parents. Clinical and molecular data were collected from 18 patients (12 males, median age 10.9 years ± 7.3), from 13 unrelated families. The age at onset ranged from birth to the first three years (median age 0.63 years ± 0.84 SD), and age at diagnosis varied from 2 months to 17 years, (median age 6.4 years ± 6.1 SD). The first sign was a psychomotor delay in 8/18 patients, epilepsy in 3/18, psychomotor delay and epilepsy in 3/18, and apneas, hypotonia, nystagmus in single cases. One patient (sibling of a previously diagnosed child) had a presymptomatic diagnosis. The diagnosis was made by exome sequencing in 7/18 patients. All patients were definitively diagnosed with ADSL deficiency based on pathogenic variants and/or biochemical assessment. One patient had a fatal neonatal form of ADSL deficiency, seven showed features fitting type I, and nine were characterized by a milder condition (type II), with two showing a very mild phenotype. Eighteen different variants were distributed along the entire ADSL coding sequence and were predicted to have a variable structural impact by impairing proper homotetramerization or catalytic activity of the enzyme. Six variants had not previously been reported. All but two variants were missense. Conclusions The study adds more details on the spectrum of ADSLD patients’ phenotypes and molecular data.

Adenylosuccinate Lyase (ADSL) functions in the de novo purine biosynthesis pathway. ADSL deficiency (ADSLD) causes numerous neurodevelopmental pathologies, including microcephaly and autism spectrum disorder. ADSLD patients have normal purine nucleotide levels but exhibit accumulation of the dephosphorylated ADSL substrates SAICAr and S-Ado. SAICAr was implicated in the neurotoxic effects of ADSLD, although its role remains unknown. We examined the effects of ADSL depletion in human cells and found increased DNA damage signaling, that was rescued by nucleosides, and impaired primary ciliogenesis, that was rescued by reducing SAICAr. By analyzing ADSL deficient chicken and zebrafish embryos we observed impaired neurogenesis and microcephaly, and neuroprogenitor attrition in zebrafish was rescued by reducing SAICAr. Zebrafish embryos also displayed phenotypes commonly linked to ciliopathies. Our results suggest that both reduced purine levels and SAICAr accumulation contribute to neurodevelopmental pathology in ADSLD and defective ciliogenesis may influence the ADSLD phenotypic spectrum.

The dreadful disease malaria is one among the infectious diseases that comes in third number after the tuberculosis and HIV. This disease is spread by female Anopheles mosquito and caused by the malarial parasite

Schistosomiasis, caused by Schistosoma mansoni trematode worm, affects more than 1.5 million people in Brazil. The current treatment consists in the administration of Praziquantel, the only medicine used for treatment for more than 40 years. Some of the limitations of this drug consist in its inactivity against schistosomula and parasite eggs, the appearance of resistant strains and non-prevention against reinfection. Thus, the objective of this study was to evaluate the effect of immunization with recombinant functional enzymes of the purine salvage pathway of S. mansoni, Nucleoside Diphosphate Kinase (NDPK) and Adenylosuccinate Lyase (ADSL), to evaluate the host immune response, as well as the parasite load after vaccination. For this, Balb/c mice were divided into 5 groups: control (uninfected and untreated), non-immunized/infected, NDPK infected, ADSL infected, and NDPK + ADSL infected. Immunized groups received three enzyme dosages, with a 15-day interval between each dose, and after 15 days of the last application the animals were infected with 80 cercariae of S. mansoni. On the 47th day after the infection, fecal eggs were counted and, on the 48th day after the infection, the evaluation of leukocyte response, parasite load, antibody production, cytokines quantification, and histopathological analysis were performed. The results showed that immunizations with NDPK, ADSL or NDPK + ADSL promoted a discreet reduction in eosinophil counts in lavage of peritoneal cavity. All immunized animals showed increased production and secretion of IgG1, IgG2a, and IgE antibodies. Increased production of IL-4 was observed in the group immunized with the combination of both enzymes (NDPK + ADSL). In addition, in all immunized groups there were reductions in egg counts in the liver and intestine, such as reductions in liver granulomas. Thus, we suggest that immunizations with these enzymes could contribute to the reduction of schistosomiasis transmission, besides being important in immunopathogenesis control of the disease.

Rationale: Adenylosuccinate lyase (ADSL) is an essential enzyme for de novo purine biosynthesis. Here we sought to investigate the putative role of ADSL in colorectal carcinoma (CRC) carcinogenesis and response to antimetabolites. Methods: ADSL expression levels were assessed by immunohistochemistry or retrieved from The Cancer Genome Atlas (TCGA) dataset. The effects of ADSL silencing or overexpression were evaluated on CRC cell proliferation, cell migration and cell-cycle. In vivo tumor growth was assessed by the chicken chorioallantoic membrane (CAM). Transfected cell lines or patient-derived organoids (PDO) were treated with 5-fluorouracil (5-FU) and 6-mercaptopurine (6-MP) and drug response was correlated with ADSL expression levels. Metabolomic and transcriptomic profiling were performed to identify dysregulated pathways and ADSL downstream effectors. Mitochondrial respiration and glycolytic capacity were measured using Seahorse; mitochondrial membrane potential and the accumulation of ROS were measured by FACS using MitoTracker Red and MitoSOX staining, respectively. Activation of canonical pathways was assessed by immunohistochemistry and immunoblotting. Results: ADSL expression is significantly increased in CRC tumors compared to non-tumor tissue. ADSL-high CRCs show upregulation of genes involved in DNA synthesis, DNA repair and cell cycle. Accordingly, ADSL overexpression accelerated progression through the cell cycle and significantly increased proliferation and migration in CRC cell lines. Additionally, ADSL expression increased tumor growth in vivo and sensitized CRCs to 6-MP in vitro, ex vivo (PDOs) and in vivo (CAM model). ADSL exerts its oncogenic function by affecting mitochondrial function via alteration of the TCA cycle and impairment of mitochondrial respiration. The KEAP1-NRF2 and mTORC1-cMyc axis are independently activated upon ADSL overexpression and may favor the survival and proliferation of ROS-accumulating cells, favoring DNA damage and tumorigenesis. Conclusions: Our results suggest that ADSL is a novel oncogene in CRC, modulating mitochondrial function, metabolism and oxidative stress, thus promoting cell cycle progression, proliferation and migration. Our results also suggest that ADSL is a predictive biomarker of response to 6-mercaptopurine in the pre-clinical setting.

We analyze the metabolomes of humans, chimpanzees and macaques in muscle, kidney and three different regions of the brain. Whereas several compounds in amino acid metabolism occur at either higher or lower concentrations in humans than in the other primates, metabolites in oxidative phosphorylation and purine biosynthesis are consistently present in lower concentrations in the brains of humans. In particular, metabolites downstream of adenylosuccinate lyase, which catalyzes two reactions in purine synthesis, occur at lower concentrations in humans. This enzyme carries an amino acid substitution that is present in all humans today but absent in Neandertals. By introducing the modern human substitution into the genomes of mice, as well as the ancestral, Neandertal-like substitution into the genomes of human cells, we show that this amino acid substitution is responsible for much or all of the reduction of de novo synthesis of purines in humans.

The protozoan Leishmania donovani, from trypanosomatids family is a deadly human pathogen responsible for causing Visceral Leishmaniasis. Unavailability of proper treatment in the developing countries has served as a major threat to the people. The absence of vaccines has made treatment possibilities to rely solely over chemotherapy. Also, reduced drug efficacy due to emerging resistant strains magnifies the threat. Despite years of formulations for an effective drug therapy, complexity of the disease is also unfortunately increasing. Absence of potential drug targets has worsened the scenario. Therefore exploring new therapeutic approach is a priority for the scientific community to combat the disease. One of the most reliable ways to alter the adversities of the infection is finding new biological targets for designing potential drugs. An era of computational biology allows identifying targets, assisting experimental studies. It includes sorting the parasite’s metabolic pathways that pins out proteins essential for its survival. We have directed our study towards a computational methodology for determining targets against L. donovani from the “purine salvage” pathway. This is a mainstay pathway towards the maintenance of purine amounts in the parasitic pool of nutrients proving to be mandatory for its survival. This study represents an integration of metabolic pathway and Protein-Protein Interactions analysis. It consists of incorporating the available experimental data to the theoretical methods with a prospective to develop a kinetic model of Purine salvage pathway. Simulation data revealed the time course mechanism of the enzymes involved in the synthesis of the metabolites. Modeling of the metabolic pathway helped in marking of crucial enzymes. Additionally, the PPI analysis of the pathway assisted in building a static interaction network for the proteins. Topological analysis of the PPI network through centrality measures (MCC and Closeness) detected targets found common with Dynamic Modeling. Therefore our analysis reveals the enzymes ADSL (Adenylosuccinate lyase) and IMPDH (Inosine-5′-monophosphate dehydrogenase) to be important having a central role in the modeled network based on PPI and kinetic modeling techniques. Further the available three dimensional structure of the enzyme “ADSL” aided towards the search for potential inhibitors against the protein. Hence, the study presented the significance of integrating methods to identify key proteins which might be putative targets against the treatment of Visceral Leishmaniasis and their potential inhibitors.

The purine salvage pathway offers potential enzyme targets for novel antimalarial agents. Blocking the pathway by which adenosine obtained from the host cell is converted to the purine nucleotides required for nucleic acid synthesis is likely to be highly detrimental to parasite survival. Research has been carried out into finding inhibitors for the first two enzymes in the pathway. Coformycins have been identified as inhibitors of adenosine deaminase, while immucillins inhibit purine nucleoside phosphorylases. However, there has been far greater research into developing inhibitors against the third enzyme in the pathway—hypoxanthine-guanine-[xanthine] phosphoribosyl transferase. These studies have mostly focused on the design of phosphonate, bisphosphonate, and aza bisphosphonate inhibitors, as well as relevant phosphoramidate prodrugs. Some immucillins have also been shown to act as inhibitors. By contrast, little research has been carried out to develop inhibitors for the final two enzymes adenylosuccinate synthase and adenylosuccinate lyase. Investigators have also looked into the possibility of developing antimalarial agents that will block the de novo synthesis of pyrimidines and pyrimidine nucleotides. The greatest level of interest has been in finding inhibitors against orotidine 5’-monophosphate decarboxylase. There has also been interest in blocking deoxyuridine triphosphate nucleotidohydrolase as it plays an important role in controlling levels of dUTP in the parasite cell.

Toxoplasma gondii is a protozoan parasite, occurring worldwide, endangers human health and causes enormous economic losses to the Ministry of Agriculture. A safe and effective vaccination is needed to handle these problems. In addition, ideal vaccine production is a challenge in the future. In this study, we knocked out the adenylosuccinate lyase (ADSL) gene and found that the gene reduces the growth rate of T. gondii tachyzoites in vitro under standard growth conditions by plaque or replication experiments. Furthermore, mice that were immunized with tachyzoites of the ME49&Delta, ADSL strain induced 100% protection efficacy against challenge with the type 1 strain RH, type 2 strain ME49 and type 3 strain VEG. All mice that were immunized with ME49&Delta, ADSL had a survival rate of 100% when they were reinfected with wild-type strains, either 30 days or 70 days after immunization, and immunization was also protective against homologous infection with 50 T. gondii ME49 tissue cysts. In addition, the level of Toxoplasma-specific IgG was significantly elevated at 30 and 70 days after immunization. ME49&Delta, ADSL induced high levels of Th1 cytokines (interferon gamma (IFN-&gamma, ), interleukin (IL)-12) at 4 weeks after immunization and spleen cell cultures from mice vaccinated for 150 days were able to produce robust INF-&gamma, and IL-12 levels in the supernatant. The results of the present study showed that &Delta, ADSL vaccination induced a T. gondii-specific cellular immune response against further infections. These results suggest that the ADSL-deficient vaccine can induce anti-Toxoplasma gondii humoral and cellular immune responses and has 100% immune protection against post-challenge by the type 1 strain RH, type 2 strain ME49 and type 3 strain VEG. It will be used as an excellent candidate for live vaccines and may contribute in a positive meaning to control human toxoplasmosis.

The dreadful disease malaria is one among the infectious diseases that comes in third number after the tuberculosis and HIV. This disease is spread by female Anopheles mosquito and caused by the malarial parasite sp notably Plasmodium falciparum. In this, the organism has several enzymes for processing the infection and growth mechanism and among that, the adenylosuccinate lyase is an enzyme that plays a critical role in metabolism and cellular replication via its action in the de novo purine biosynthetic pathway. Adenylosuccinate has been studied for two reaction mechanisms, and in that, the adenylosuccinate to AMP and fumarate is core important. As of now, there have been several studies indicating the reaction mechanism of adenylosuccinate lyase, this study projects the conformations of the reactant and product changes through molecular docking and molecular dynamic simulations. Adenylosuccinate bound complex involves His role in the product than the reactant complex, and the complex shows high flexibility due to fumarate. Thus, identifying the core inhibitor that binds to His rings could be a standard adenylosuccinate lyase inhibitor, that can block the malarial diseases in humans. In addition to the competitive inhibition site, we also predicted the uncompetitive ligand binding site, which suggest the alternate region to be targeted. Thus, from this work, we suggest both competitive and uncompetitive binding regions for the purpose identifying the malarial inhibitors.

International audience; The availability of genomic data from extinct homini such as Neanderthals has caused a revolution in palaeontology allowing the identification of modern human-specific protein substitutions. Currently, little is known as to how these substitutions alter the proteins on a molecular level. Here, we investigate adenylosuccinate lyase, a conserved enzyme involved in purine metabolism for which several substitutions in the modern human protein (hADSL) have been described to affect intelligence and behaviour. During evolution, modern humans acquired a specific substitution (Ala429Val) in ADSL distinguishing it from the ancestral variant present in Neanderthals (nADSL). We show here that despite this conservative substitution being solvent exposed and located distant from the active site, there is a difference in thermal stability, but not enzymology or ligand binding between nADSL and hADSL. Substitutions near residue 429 which do not profoundly affect enzymology were previously reported to cause neurological symptoms in humans. This study also reveals that ADSL undergoes conformational changes during catalysis which, together with the crystal structure of a hitherto undetermined product bound conformation, explains the molecular origin of disease for several modern human ADSL mutants.

Acid tolerance is one of the critical factors to evaluate the quality of the industrial production strains, especially organic acid producing microorganisms. To circumvent this problem, we investigated the physiological function of adenylosuccinate lyase in AMP metabolism from Candida glabrata by deleting the corresponding gene, CgADE13. At pH 4.0, CgADE13 deletion resulted in a 68.3% and 112.0% increase in biomass and cell viability compared to those of wild type strain (wt), respectively. In addition, CgADE13 deletion also protected cell morphology and counteracted ROS production. Further, the intracellular ATP level of strain Cgade13Δ was decreased by 25.0%, and its H+-ATPase activity was increased by 15.0%. Finally, pyruvate production with strain Cgade13Δ in a 30-L batch bioreactor at pH 4.0 reached 53.9 g/L, and pyruvate productivity was increased by 166.7% compared to that of wt. This is the first report regarding tolerance engineering of C. glabrata for enhancing pyruvate productivity, which provides a good starting point for metabolic engineering to achieve the industrial production of other chemicals.

Background New World vultures (Cathartiformes: Cathartidae) are obligate scavengers comprised of seven species in five genera throughout the Americas. Of these, turkey vultures (Cathartes aura) and black vultures (Coragyps atratus) are the most widespread and, although ecologically similar, have evolved differences in morphology, physiology, and behaviour. Three species of haemosporidians have been reported in New World vultures to date: Haemoproteus catharti, Leucocytozoon toddi and Plasmodium elongatum, although few studies have investigated haemosporidian parasites in this important group of species. In this study, morphological and molecular methods were used to investigate the epidemiology and molecular biology of haemosporidian parasites of New World vultures in North America. Methods Blood and/or tissue samples were obtained from 162 turkey vultures and 95 black vultures in six states of the USA. Parasites were identified based on their morphology in blood smears, and sequences of the mitochondrial cytochrome b and nuclear adenylosuccinate lyase genes were obtained for molecular characterization. Results No parasites were detected in black vultures, whereas 24% of turkey vultures across all sampling locations were positive for H. catharti by blood smear analysis and/or PCR testing. The phylogenetic analysis of cytochrome b gene sequences revealed that H. catharti is closely related to MYCAMH1, a yet unidentified haemosporidian from wood storks (Mycteria americana) in southeastern USA and northern Brazil. Haemoproteus catharti and MYCAMH1 represent a clade that is unmistakably separate from all other Haemoproteus spp., being most closely related to Haemocystidium spp. from reptiles and to Plasmodium spp. from birds and reptiles. Conclusions Haemoproteus catharti is a widely-distributed parasite of turkey vultures in North America that is evolutionarily distinct from other haemosporidian parasites. These results reveal that the genetic diversity and evolutionary relationships of avian haemosporidians are still being uncovered, and future studies combining a comprehensive evaluation of morphological and life cycle characteristics with the analysis of multiple nuclear and mitochondrial genes will be useful to redefine the genus boundaries of these parasites and to re-evaluate the relationships amongst haemosporidians of birds, reptiles and mammals. Electronic supplementary material The online version of this article (10.1186/s12936-017-2165-5) contains supplementary material, which is available to authorized users.

Adenylosuccinate lyase (ASL) is involved in both de novo and salvage pathways of purine biosynthesis. ASL belongs to the argininosuccinate lyase/fumarase C superfamily of enzymes which share a general acid–base catalytic mechanism with β-elimination of fumarate as the common product. Cloning, expression, and a method to obtain homogeneous recombinant ASL from Leishmania braziliensis (LbASL) are described. Mass spectrometry analysis of recombinant LbASL, oligomeric state determination and multiple sequence alignment are presented. Steady-state kinetics of LbASL showed a Michaelis–Menten pattern. Isothermal titration calorimetry binding assays suggested that LbASL follows a Uni-Bi ordered kinetic mechanism, in which release of fumarate is followed by AMP to yield free enzyme. Initial velocity data for the reverse reaction and the Haldane relationship allowed calculation of an unfavorable equilibrium constant for the LbASL-catalyzed chemical reaction. The activation energy and thermodynamic activation parameters were estimated. Solvent kinetic isotope effects V/K and V suggest a modest contribution of solvent proton transference during the rate-limiting step of the reaction. Proton inventory data show that the modest normal effect on V arises from a single protonic site, and the transition state fractionation factor value of 0.74 suggests participation of solvent proton transfer in transition-state vibrations perpendicular to the reaction coordinate. pH-rate profiles for kcat and kcat/KM suggested amino acid residues involved in, respectively, catalysis and substrate binding. A model of LbASL was built to provide a structural basis for the experimental data. A better understanding of the mode of action of LbASL is useful for the rational design of antileishmaniasis agents.

Hydroxylation is a post-translational modification affecting protein stability, activity or interactome. We identified adenylosuccinate lyase (ADSL) as a novel hydroxylation substrate in triple negative breast cancer. Hydroxylation affects ADSL enzymatic activity and, therefore, adenosine levels. Adenosine, in turn, favors the translation of cMYC, triggering its oncogenic downstream cascade.

Adenylosuccinate lyase (ADSL) catalyzes two steps in de novo purine synthesis (DNPS). Mutations in ADSL can result in inborn errors of metabolism characterized by developmental delay and disorder phenotypes, with no effective treatment options. Recently, SAICAR, a metabolic substrate of ADSL, has been found to have alternative roles in the cell, complicating the role of ADSL. crADSL, a CRISPR KO of ADSL in HeLa cells, was constructed to investigate DNPS and ADSL in a human cell line. Here we employ this cell line in an RNA-seq analysis to initially investigate the effect of DNPS and ADSL deficiency on the transcriptome as a first step in establishing a cellular model of ADSL deficiency. We report transcriptome changes in genes relevant to development, vascular development, muscle, and cancer biology, which provide interesting avenues for future research. Keywords: RNA-seq, Purine synthesis, Transcriptome, Adenylosuccinate lyase

Protein hydroxylation affects protein stability, activity, and interactome, therefore contributing to various diseases including cancers. However, the transiency of the hydroxylation reaction hinders the identification of hydroxylase substrates. By developing an enzyme-substrate trapping strategy coupled with TAP-TAG or orthogonal GST- purification followed by mass spectrometry, we identify adenylosuccinate lyase (ADSL) as an EglN2 hydroxylase substrate in triple negative breast cancer (TNBC). ADSL expression is higher in TNBC than other breast cancer subtypes or normal breast tissues. ADSL knockout impairs TNBC cell proliferation and invasiveness in vitro and in vivo. An integrated transcriptomics and metabolomics analysis reveals that ADSL activates the oncogenic cMYC pathway by regulating cMYC protein level via a mechanism requiring ADSL proline 24 hydroxylation. Hydroxylation-proficient ADSL, by affecting adenosine levels, represses the expression of the long non-coding RNA MIR22HG, thus upregulating cMYC protein level. Our findings highlight the role of ADSL hydroxylation in controlling cMYC and TNBC tumorigenesis., The hydroxylase EgIN2 contributes to triple negative breast cancers. Here, using an enzyme-substrate trapping strategy, the authors identify ASDL as a bona fide substrate of EgIN2 promoting aggressive properties of TNBC via the activation of cMYC signaling.

A 2-day-old male infant born at 38 weeks to a gravida 1, para 1 woman is brought to the emergency department secondary to concerns for hypothermia, poor feeding, and decreased urine output. Prenatal laboratory results are unremarkable, with the exception of group B Streptococcus colonization that was adequately treated with penicillin prophylaxis before delivery. The delivery course was notable for thick meconium for which the infant underwent intubation and suctioning with subsequent extubation. The infant’s Apgar scores were 4 and 9 at 1 and 5 minutes, respectively. In the nursery, the infant was noted to be breastfeeding well and had passed stools and voided appropriately. He was discharged on day 2 after birth. After discharge, the parents contacted the infant’s physician to report decreased interest in feeding, decreased activity, and low rectal temperature of 93.9°F (34.4°C). The family was instructed to take the infant to the emergency department for further evaluation and treatment. On arrival at the emergency department, the infant was noted to have a temperature of 96.9°F (36.1°C) and to be listless, and was thus taken to a resuscitation bay. Initial physical examination showed an ill-appearing infant with tacky mucous membranes and an exaggerated Moro reflex. He was given a 10-mL/kg normal saline bolus and a 15-mL/kg normal saline bolus. Initial laboratory findings include the following: white blood cells 22,000/μL(22×109/L); hemoglobin 13.3 g/dL (133 g/L); hematocrit 36.5%; platelet count, 565×103/μL (565×109/L); neutrophils 80%; bands 1%; lymphocytes 12%; monocytes 5%; sodium 154 mEq/L (154 mmol/L); potassium 5.1 mEq/L (5.1 mmol/L); chloride 115 mEq/L (115 mmol/L); bicarbonate 20 mEq/L (20 mmol/L); blood …