Phylogenetic analysis reveals a novel protein family closely related to adenosine deaminase

Adenosine Deaminase-Like Gene-Carried Lentivirus Toolkit for Identification of DNA N6-Methyladenine Origins

Post-replicative DNA N6-methyladenine (pr6mdA) can form via bona fide methylase-catalyzed adenine methylation, playing a pivotal role in embryonic development and other biological processes. Surprisingly, pre-methylated adenine can be erroneously incorporated into DNA as misincorporated N6-methyladenine (i6mdA) via DNA polymerase-mediated replication. Despite pr6mdA and i6mdA sharing identical chemical structures, their biological functions diverge significantly, presenting a substantial challenge in distinguishing between the two. Here, for the first-time, it is exploited that the adenosine deaminase-like (Adal) protein and a corresponding activity-null mutant to construct an Adal lentivirus toolkit. With this newly designed toolkit, both pr6mdA and i6mdA can be identified and quantified simultaneously. The presence of 6mdA in the bone marrow cells of mice is shown, with its levels serving as indicators for growth with age, probably reflecting the cellular stress-caused changes in RNA decay, nucleotide pool sanitation, and transcription. Collectively, a powerful toolkit to advance understanding of both pr6mdA and i6mdA is demonstrated.

The AMP deaminase of the mollusk Helix pomatia is an unexpected member of the adenosine deaminase-related growth factor (ADGF) family

We report here the first occurrence of an adenosine deaminase-related growth factor (ADGF) that deaminates adenosine 5' monophosphate (AMP) in preference to adenosine. The ADGFs are a group of secreted deaminases found throughout the animal kingdom that affect the extracellular concentration of adenosine by converting it to inosine. The AMP deaminase studied here was first isolated and biochemically characterized from the roman snail Helix pomatia in 1983. Determination of the amino acid sequence of the AMP deaminase enabled sequence comparisons to protein databases and revealed it as a member of the ADGF family. Cloning and expression of its cDNA in Pichia pastoris allowed the comparison of the biochemical characteristics of the native and recombinant forms of the enzyme and confirmed they correspond to the previously reported activity. Uncharacteristically, the H. pomatia AMP deaminase was determined to be dissimilar to the AMP deaminase family by sequence comparison while demonstrating similarity to the ADGFs despite having AMP as its preferred substrate rather than adenosine.

Substrate Specificity of GSDA Revealed by Cocrystal Structures and Binding Studies

In plants, guanosine deaminase (GSDA) catalyzes the deamination of guanosine for nitrogen recycling and re-utilization. We previously solved crystal structures of GSDA from Arabidopsis thaliana (AtGSDA) and identified several novel substrates for this enzyme, but the structural basis of the enzyme activation/inhibition is poorly understood. Here, we continued to solve 8 medium-to-high resolution (1.85-2.60 Å) cocrystal structures, which involved AtGSDA and its variants bound by a few ligands, and investigated their binding modes through structural studies and thermal shift analysis. Besides the lack of a 2-amino group of these guanosine derivatives, we discovered that AtGSDA's inactivity was due to the its inability to seclude its active site. Furthermore, the C-termini of the enzyme displayed conformational diversities under certain circumstances. The lack of functional amino groups or poor interactions/geometries of the ligands at the active sites to meet the precise binding and activation requirements for deamination both contributed to AtGSDA's inactivity toward the ligands. Altogether, our combined structural and biochemical studies provide insight into GSDA.

Characterization and Expression Analysis of Mollusk-like Growth Factor: A Secreted Protein Involved in Pacific Abalone Embryonic and Larval Development

Simple Summary

The Pacific abalone, Haliotis discus hannai, is a gastropod mollusk in high demand, which is extensively cultured in many Asian countries. The growth and development of Pacific abalone depend on the activation of growth factors and other growth-regulating proteins. Growth factors are secreted, biologically active molecules that stimulate cell growth through signal transduction pathways. The mollusk-like growth factor (MLGF) is a mollusk specific growth factor in the adenosine deaminase related growth factor subfamily having a conserved adenosine deaminase (ADA) domain. Molecular functions of this growth factor include adenosine deaminase activity, growth factor activity, and zinc binding activity. For this growth factor activity, enzymatic activity (ADA activity) that converts adenosine to inosine to stimulate cell growth is essential. As abalone aquaculture completely depends on hatchery-produced seed, proper embryonic and larval development is essential, and MLGF is one of the main growth factors that can regulate this activity. In Pacific abalone, higher expression of Hdh-MLGF mRNA in the embryonic and larval development stages is an indication of higher production of adenosine and increases the growth factor activity that stimulates embryonic and larval cell growth through signal transduction pathways.

Abstract

Growth factors are mostly secreted proteins that play key roles in an organism’s biophysical processes through binding to specific receptors on the cell surface. The mollusk-like growth factor (MLGF) is a novel cell signaling protein in the adenosine deaminase-related growth factor (ADGF) subfamily. In this study, the MLGF gene was cloned and characterized from the digestive gland tissue of Pacific abalone and designated as Hdh-MLGF. The transcribed full-length sequence of Hdh-MLGF was 1829 bp long with a 1566 bp open reading frame (ORF) encoding 521 amino acids. The deduced amino acid sequence contained a putative signal peptide and two conserved adenosine deaminase domains responsible for regulating molecular function. Fluorescence in situ hybridization localized Hdh-MLGF in the submucosa layer of digestive tubules in the digestive gland. The mRNA expression analysis indicated that Hdh-MLGF expression was restricted to the digestive gland in the adult Pacific abalone. However, Hdh-MLGF mRNA expressions were observed in all stages of embryonic and larval development, suggesting Hdh-MLGF might be involved in the Pacific abalone embryonic and larval development. This is the first study describing Hdh-MLGF and its involvement in the Pacific abalone embryonic and larval development.

Role of MicroRNA-Like RNAs in the Regulation of Spore Morphological Differences in the Entomopathogenic Fungus Metarhizium acridum

Metarhizium acridum is an important microbial pesticide. Conidia (CO) and blastospores (BS) are two types of spores that occur in different patterns in the M. acridum life cycle and exhibit significant differences in cell morphology, structure, and activity. It may suggest that the fungus has a complex gene regulation mechanism. While previous studies on the differences between CO and BS have mainly focused on cell structure and application, little is known regarding the differences between CO and BS in fungi on the transcriptome levels. MicroRNAs (miRNAs) are small noncoding RNAs crucial to gene regulation and cell function. Understanding the miRNA-like RNAs (milRNA) and mRNA expression profiles related to cell growth and cellular morphological changes would elucidate the roles of miRNAs in spore morphological differences. In this study, 4,646 differentially expressed genes (DEGs) were identified and mainly classified in the GO terms cell, cell part, biological process, and catalytic activity. The KEGG annotation suggested that they were enriched in amino acid biosynthesis, carbohydrate metabolism, ribosome, and oxidative phosphorylation and might be involved in cell activity and structure. There were 113 differentially expressed milRNAs (DEMs), targeting 493 DEGs. Target gene functional analysis revealed that the target genes were mainly enriched in RNA transport, purine metabolism, and the cell cycle. In addition, we identified essential genes from milRNA-mRNA pairs that might participate in cell budding growth and cell membrane and wall integrity, including adenosine deaminase, glycosyl hydrolase, and G-patch domain protein (dno-miR-328-3p), WD repeat-containing protein pop1 (age-miR-127), and GPI-anchored wall transfer protein (cgr-miR-598). MilRNAs might therefore play a crucial role in cell growth and cellular morphological changes as transcriptional and post-transcriptional regulators.

Enzymatic deamination of the epigenetic nucleoside N6-methyladenosine regulates gene expression

N⁶-methyladenosine (m⁶A) modification is the most extensively studied epigenetic modification due to its crucial role in regulating an array of biological processes. Herein, Bsu06560, formerly annotated as an adenine deaminase derived from Bacillus subtilis 168, was recognized as the first enzyme capable of metabolizing the epigenetic nucleoside N⁶-methyladenosine. A model of Bsu06560 was constructed, and several critical residues were putatively identified via mutational screening. Two mutants, F91L and Q150W, provided a superiorly enhanced conversion ratio of adenosine and N⁶-methyladenosine. The CRISPR-Cas9 system generated Bsu06560-knockout, F91L, and Q150W mutations from the B. subtilis 168 genome. Transcriptional profiling revealed a higher global gene expression level in BS-F91L and BS-Q150W strains with enhanced N⁶-methyladenosine deaminase activity. The differentially expressed genes were categorized using GO, COG, KEGG and verified through RT-qPCR. This study assessed the crucial roles of Bsu06560 in regulating adenosine and N⁶-methyladenosine metabolism, which influence a myriad of biological processes. This is the first systematic research to identify and functionally annotate an enzyme capable of metabolizing N⁶-methyladenosine and highlight its significant roles in regulation of bacterial metabolism. Besides, this study provides a novel method for controlling gene expression through the mutations of critical residues.

Enzyme Replacement Therapy for Genetic Disorders Associated with Enzyme Deficiency

Mutations in human genes might lead to loss of functional proteins, causing diseases. Among these genetic disorders, a large class is associated with the deficiency in metabolic enzymes, resulting in both an increase in the concentration of substrates and a loss in the metabolites produced by the catalyzed reactions. The identification of therapeutic actions based on small molecules represents a challenge to medicinal chemists because the target is missing. Alternative approaches are biology-based, ranging from gene and stem cell therapy, CRISPR/Cas9 technology, distinct types of RNAs, and enzyme replacement therapy (ERT). This review will focus on the latter approach that since the 1990s has been successfully applied to cure many rare diseases, most of them being lysosomal storage diseases or metabolic diseases. So far, a dozen enzymes have been approved by FDA/EMA for lysosome storage disorders and only a few for metabolic diseases. Enzymes for replacement therapy are mainly produced in mammalian cells and some in plant cells and yeasts and are further processed to obtain active, highly bioavailable, less degradable products. Issues still under investigation for the increase in ERT efficacy are the optimization of enzymes interaction with cell membrane and internalization, the reduction in immunogenicity, and the overcoming of blood-brain barrier limitations when neuronal cells need to be targeted. Overall, ERT has demonstrated its efficacy and safety in the treatment of many genetic rare diseases, both saving newborn lives and improving patients' life quality, and represents a very successful example of targeted biologics.

Adenosine Receptor and Its Downstream Targets, Mod(mdg4) and Hsp70, Work as a Signaling Pathway Modulating Cytotoxic Damage in Drosophila

Adenosine (Ado) is an important signaling molecule involved in stress responses. Studies in mammalian models have shown that Ado regulates signaling mechanisms involved in “danger-sensing” and tissue-protection. Yet, little is known about the role of Ado signaling in Drosophila. In the present study, we observed lower extracellular Ado concentration and suppressed expression of Ado transporters in flies expressing mutant huntingtin protein (mHTT). We altered Ado signaling using genetic tools and found that the overexpression of Ado metabolic enzymes, as well as the suppression of Ado receptor (AdoR) and transporters (ENTs), were able to minimize mHTT-induced mortality. We also identified the downstream targets of the AdoR pathway, the modifier of mdg4 (Mod(mdg4)) and heat-shock protein 70 (Hsp70), which modulated the formation of mHTT aggregates. Finally, we showed that a decrease in Ado signaling affects other Drosophila stress reactions, including paraquat and heat-shock treatments. Our study provides important insights into how Ado regulates stress responses in Drosophila.

Cecr2 mutant mice as a model for human cat eye syndrome

Cat eye syndrome (CES), a human genetic disorder caused by the inverted duplication of a region on chromosome 22, has been known since the late 1890s. Despite the significant impact this disorder has on affected individuals, models for CES have not been produced due to the difficulty of effectively duplicating the corresponding chromosome region in an animal model. However, the study of phenotypes associated with individual genes in this region such as CECR2 may shed light on the etiology of CES. In this study we have shown that deleterious loss of function mutations in mouse Cecr2 effectively demonstrate many of the abnormal features present in human patients with CES, including coloboma and specific skeletal, kidney and heart defects. Beyond phenotypic analyses we have demonstrated the importance of utilizing multiple genetic backgrounds to study disease models, as we see major differences in penetrance of Cecr2-related abnormal phenotype between mouse strains, reminiscent of the variability in the human syndrome. These findings suggest that Cecr2 is involved in the abnormal features of CES and that Cecr2 mice can be used as a model system to study the wide range of phenotypes present in CES.

Random acceleration and steered molecular dynamics simulations reveal the (un)binding tunnels in adenosine deaminase and critical residues in tunnels

Adenosine deaminase (ADA) is an important enzyme related to purine nucleoside metabolism in human serum and various tissues. Abnormal ADA levels are related to a wide variety of diseases such as rheumatoid arthritis, AIDS, anemia, lymphoma, and leukemia and ADA is considered as a useful target for various diseases. Currently, ADA can be divided into open conformation and closed conformation according to the inhibitors of binding. As a consequence, we chose two inhibitors, namely, 6-hydroxy-1,6-dihydro purine nucleoside (PRH) and N-[4,5-bis(4-hydroxyphenyl)-1,3-thiazol-2-yl]hexanamide (FRK) to bind to ADA in the closed conformation or open conformation respectively. In this study, we performed the random acceleration molecular dynamics (RAMD) method, steered molecular dynamics (SMD) simulations and adaptive basing force (ABF) simulation to explore the unbinding tunnels and tunnel characteristics of the two inhibitors in ADA. Our results showed that PRH and FRK escaped from ADA using three main tunnels (namely, T1, T2, and T3). Inhibitors (PRH and FRK) escape through T3 more frequently and more easily. The results from ABF simulations confirm that the free energy barrier in T1 or T2 is larger than that in T3 when inhibitors dissociate from the ADA and have potential mean of force (PMF) depth. Moreover, in the complexes (ADA-PRH, ADA-FRK), we also found that the most active residue that remarkably contributed to the binding affinity is W117 in T3, and the residue played an important role in the unbinding tunnel for inhibitor leaving. Our theoretical study provided insight into the ADA inhibitor passway mechanism and may be a clue for potent ADA inhibitor design.

Adenosine deaminase 2 activity negatively correlates with age during childhood

BACKGROUND

Human adenosine deaminase 2 (ADA2) is an extracellular enzyme that negatively regulates adenosine-mediated cell signaling by converting adenosine to inosine. Altered ADA2 enzyme activity has been associated with some viral infections and rheumatic diseases. The potential utility of ADA2 as a biomarker is, however, limited by the absence of established ranges of ADA2 concentration and enzyme activity in the healthy population. It is known that ADA2 enzyme activity is lower in adults, but when (and why) this decline happens is not known. The purpose of this study was to establish normative ranges of ADA2 enzyme activity and protein concentration in the healthy pediatric population.

METHODS

We modified a commercially available ADA2 enzyme activity assay to enable higher throughput analysis of fresh, frozen and hemolyzed blood samples. With this assay and ADA2 protein immunoblotting, we analyzed ADA2 enzyme activity and protein concentration in blood plasma from a cohort of children and adolescents (n = 94) aged 5 months to 18 years. One-way ANOVA with subsequent Tukey multiple comparison test was used to analyze group differences. Reference intervals were generated using the central 95% of the population (2-97.5 percentiles).

RESULTS

ADA2 enzyme activity was consistent in fresh, frozen, and hemolyzed sera and plasma as measured by our modified assay. Analysis of plasma samples from the healthy pediatric cohort revealed that ADA2 enzyme activity is significantly lower in older children than in younger children (p < 0.0001). In contrast, there was no significant correlation between ADA2 protein concentration and either age or ADA2 enzyme activity.

CONCLUSION

We observed that ADA2 enzyme activity, but not ADA2 protein concentration, negatively correlates with age in a cohort of children and adolescents. Our findings stress the importance of appropriate age-matched controls for assessing ADA2 enzyme activity in the clinical setting.

Alternative conformation induced by substrate binding for Arabidopsis thalianaN6-methyl-AMP deaminase

Adenosine deaminase is involved in adenosine degradation and salvage pathway, and plays important physiological roles in purine metabolism. Recently, a novel type of adenosine deaminase-like protein has been identified, which displays deamination activity toward N⁶-methyl-adenosine monophosphate but not adenosine or AMP, and was consequently named N⁶-methyl-AMP deaminase (MAPDA). The underlying structural basis of MAPDA recognition and catalysis is poorly understood. Here, we present the crystal structures of MAPDA from Arabidopsis thaliana in the free and in the ligand-bound forms. The protein contains a conserved (β/α)₈ Tim-barrel domain and a typical zinc-binding site, but it also exhibits idiosyncratic local differences for two flexible helices important for substrate binding. The extensive interactions between the N⁶-methyl-AMP substrate or the inosine monophosphate product and the enzyme were identified, and subsequently evaluated by the deamination activity assays. Importantly, each structure reported here represents a different stage of the catalytic pathway and their structural differences suggested that the enzyme can exist in two distinct conformational states. The open state switches to the closed one upon the binding of ligands, brought about by the two critical helices. Our structural studies provide the first look of this important metabolic enzyme and shed lights on its catalytic pathway, which holds promise for the structure-based drug design for MAPDA-related diseases.

Identification of Novel Adenosine Deaminase 2 Gene Variants and Varied Clinical Phenotype in Pediatric Vasculitis

OBJECTIVE

Individuals with deficiency of adenosine deaminase 2 (DADA2), a recently recognized autosomal recessive disease, present with various systemic vascular and inflammatory manifestations, often with young age at disease onset or with early onset of recurrent strokes. Their clinical features and histologic findings overlap with those of childhood-onset polyarteritis nodosa (PAN), a primary "idiopathic" systemic vasculitis. Despite similar clinical presentation, individuals with DADA2 may respond better to biologic therapy than to traditional immunosuppression. The aim of this study was to screen an international registry of children with systemic primary vasculitis for variants in ADA2.

METHODS

The coding exons of ADA2 were sequenced in 60 children and adolescents with a diagnosis of PAN, cutaneous PAN, or unclassifiable vasculitis (UCV), any chronic vasculitis with onset at age 5 years or younger, or history of stroke. The functional consequences of the identified variants were assessed by ADA2 enzyme assay and immunoblotting.

RESULTS

Nine children with DADA2 (5 with PAN, 3 with UCV, and 1 with antineutrophil cytoplasmic antibody-associated vasculitis) were identified. Among them, 1 patient had no rare variants in the coding region of ADA2 and 8 had biallelic, rare variants (minor allele frequency <0.01) with a known association with DADA2 (p.Gly47Arg and p.Gly47Ala) or a novel association (p.Arg9Trp, p.Leu351Gln, and p.Ala357Thr). The clinical phenotype varied widely.

CONCLUSION

These findings support previous observations indicating that DADA2 has extensive genotypic and phenotypic variability. Thus, screening ADA2 among children with vasculitic rash, UCV, PAN, or unexplained, early-onset central nervous system disease with systemic inflammation may enable an earlier diagnosis of DADA2.

Structure of Arabidopsis thaliana N6-methyl-AMP deaminase ADAL with bound GMP and IMP and implications for N6-methyl-AMP recognition and processing

Arabidopsis thaliana aminohydrolase (AtADAL) has been shown to be involved in the metabolism of N⁶-methyl-AMP, a proposed intermediate during m⁶A-modified RNA metabolism, which can be subsequently incorporated into newly synthesized RNA by Pol II. It has been proposed that AtADAL will prevent N⁶-methyl-AMP reuse and catabolize it to inosine monophosphate (IMP). Here, we have solved the crystal structures of AtADAL in the apo form and in complex with GMP and IMP in the presence of Zn²⁺. We have identified the substrate-binding pocket of AtADAL and compared it with that for adenosine deaminase (ADA), adenine deaminase (ADE) and AMP deaminase (AMPD) from multiple species. The comparisons reveal that plant ADAL1 may have the potential ability to catalyze different alkyl-group substituted substrates.

Integrated genetic and epigenetic prediction of coronary heart disease in the Framingham Heart Study

An improved method for detecting coronary heart disease (CHD) could have substantial clinical impact. Building on the idea that systemic effects of CHD risk factors are a conglomeration of genetic and environmental factors, we use machine learning techniques and integrate genetic, epigenetic and phenotype data from the Framingham Heart Study to build and test a Random Forest classification model for symptomatic CHD. Our classifier was trained on n = 1,545 individuals and consisted of four DNA methylation sites, two SNPs, age and gender. The methylation sites and SNPs were selected during the training phase. The final trained model was then tested on n = 142 individuals. The test data comprised of individuals removed based on relatedness to those in the training dataset. This integrated classifier was capable of classifying symptomatic CHD status of those in the test set with an accuracy, sensitivity and specificity of 78%, 0.75 and 0.80, respectively. In contrast, a model using only conventional CHD risk factors as predictors had an accuracy and sensitivity of only 65% and 0.42, respectively, but with a specificity of 0.89 in the test set. Regression analyses of the methylation signatures illustrate our ability to map these signatures to known risk factors in CHD pathogenesis. These results demonstrate the capability of an integrated approach to effectively model symptomatic CHD status. These results also suggest that future studies of biomaterial collected from longitudinally informative cohorts that are specifically characterized for cardiac disease at follow-up could lead to the introduction of sensitive, readily employable integrated genetic-epigenetic algorithms for predicting onset of future symptomatic CHD.

Genetic Variability in Adenosine Deaminase-Like Contributes to Variation in Alcohol Preference in Mice

BACKGROUND

A substantial part of the risk for alcohol use disorder is determined by genetic factors. We previously used chromosome substitution (CSS) mice, to identify a quantitative trait loci (QTL) for alcohol preference on mouse chromosome 2. The aim of this study was to identify candidate genes within this QTL that confer the risk for alcohol preference.

METHODS

In order to delineate the neurobiological underpinnings of alcohol consumption, we expanded on the QTL approach to identify candidate genes for high alcohol preference in mice. We narrowed down a QTL for alcohol preference on mouse chromosome 2, that we previously identified using CSS mice, to 4 candidate genes in silico. Expression levels of these candidate genes in prefrontal cortex, amygdala, and nucleus accumbens-brain regions implicated in reward and addiction-were subsequently compared for the CSS-2 and the C57BL/6J host strain.

RESULTS

We observed increased expression of adenosine deaminase-like (Adal) in all 3 regions in CSS-2 mice. Moreover, we found that the adenosine deaminase inhibitor EHNA reduced the difference in alcohol preference between CSS-2 and C57BL/6J mice.

CONCLUSIONS

This study identifies Adal as a genetically protective factor against alcohol consumption in mice, in which elevated Adal levels contribute to low alcohol preference.

Application of ADA1 as a new marker enzyme in sandwich ELISA to study the effect of adenosine on activated monocytes

Enzyme-linked immunosorbent assay (ELISA) is a valuable technique to detect antigens in biological fluids. Horse radish peroxidase (HRP) is one of the most common enzymes used for signal amplification in ELISA. Despite new advances in technology, such as a large-scale production of recombinant enzymes and availability of new detection systems, limited research is devoted to finding alternative enzymes and their substrates to amplify the ELISA signals. Here, HRP-avidin was substituted with the human adenosine deaminase (hADA1)-streptavidin complex and adenosine as a detection system in commercial ELISA kits. The hADA1 ELISA was successfully used to demonstrate that adenosine, bound to A1 and A3 adenosine receptors, increases cytokine secretion by LPS activated monocytes. We show that hADA1-based ELISA has the same sensitivity, and also provides identical results, as HRP ELISA. In addition, the sensitivity of hADA1-based ELISA could be easily adjusted by changing the adenosine concentration and the incubation time. Therefore, hADA1 could be used as a detection enzyme with any commercial ELISA kit with a wide range of concentration of antigens.

Analysis of Extracellular Nucleotide Metabolism in Adult Zebrafish After Embryological Exposure to Valproic Acid

Autism is a neurodevelopmental disorder characterized by symptoms related to stereotyped movements, deficits in social interaction, impaired communication, anxiety, hyperactivity, and the presence of restricted interests. Evidence indicates an important role of extracellular ATP and adenosine as signaling molecules in autism. ATP hydrolysis by ectonucleotidases is an important source of adenosine, and adenosine deaminase (ADA) contributes to the control of the nucleoside concentrations. Considering zebrafish is an animal model that may contribute towards to understanding the mechanisms that underlie social behavior, we investigated the purinergic signaling in a model of embryological exposure to valproic acid (VPA) that induces social interaction deficit in adult zebrafish. We demonstrated embryological exposure to VPA did not change ATP and ADP hydrolysis in zebrafish at 120 dpf, and the cytosolic (soluble) ADA activity was not altered. However, we observed an increase of AMP hydrolysis (12.5 %) whereas the ecto-ADA activity was decreased (19.2 %) in adult zebrafish submitted to embryological exposure to VPA. Quantitative reverse transcription PCR (RT-PCR) analysis showed changes on ntpd8, ADA 2.1, and A2a1 mRNA transcript levels. Brain ATP metabolism showed a rapid catabolism of ATP and ADP, whereas the extracellular metabolism of AMP and adenosine (ADO) occurred slowly. We demonstrated that embryological exposure to VPA altered biochemical and molecular parameters related to purinergic system in adult zebrafish. These findings indicate that the enzyme activities involved in the control of ATP and adenosine levels may be involved in the pathophysiological mechanisms of diseases related to the impairment of social interaction, such as autism.

Hyperglycemia alters E-NTPDases, ecto-5'-nucleotidase, and ectosolic and cytosolic adenosine deaminase activities and expression from encephala of adult zebrafish (Danio rerio)

Hyperglycemia is the main feature for the diagnosis of diabetes mellitus (DM). Some studies have demonstrated the relationship between DM and dysfunction on neurotransmission systems, such as the purinergic system. In this study, we evaluated the extracellular nucleotide hydrolysis and adenosine deamination activities from encephalic membranes of hyperglycemic zebrafish. A significant decrease in ATP, ADP, and AMP hydrolyses was observed at 111-mM glucose-treated group, which returned to normal levels after 7 days of glucose withdrawal. A significant increase in ecto-adenosine deaminase activity was observed in 111-mM glucose group, which remain elevated after 7 days of glucose withdrawal. The soluble-adenosine deaminase activity was significantly increased just after 7 days of glucose withdrawal. We also evaluated the gene expressions of ecto-nucleoside triphosphate diphosphohydrolases (E-NTPDases), ecto-5'-nucleotidase, ADA, and adenosine receptors from encephala of adult zebrafish. The entpd 2a.1, entpd 2a.2, entpd 3, and entpd 8 mRNA levels from encephala of adult zebrafish were decreased in 111-mM glucose-treated and glucose withdrawal groups. The gene expressions of adenosine receptors (adora 1 , adora 2aa , adora 2ab , and adora 2b ) were decreased in 111-mM glucose-treated and glucose withdrawal groups. The gene expression of ADA (ada 2a.1) was decreased in glucose withdrawal group. Maltodextrin, used as a control, did not affect the expression of adenosine receptors, ADA and E-NTPDases 2, 3, and 8, while the expression of ecto-5'-nucleotidase was slightly increased and the E-NTPDases 1 decreased. These findings demonstrated that hyperglycemia might affect the ecto-nucleotidase and adenosine deaminase activities and gene expression in zebrafish, probably through a mechanism involving the osmotic effect, suggesting that the modifications caused on purinergic system may also contribute to the diabetes-induced progressive cognitive impairment.

Injury and immune response: applying the danger theory to mosquitoes

The insect immune response can be activated by the recognition of both non-self and molecular by-products of tissue damage. Since pathogens and tissue damage usually arise at the same time during infection, the specific mechanisms of the immune response to microorganisms, and to tissue damage have not been unraveled. Consequently, some aspects of damage caused by microorganisms in vector-borne arthropods have been neglected. We herein reassess the Anopheles-Plasmodium interaction, incorporating Matzinger's danger/damage hypothesis and George Salt's injury assumptions. The invasive forms of the parasite cross the peritrophic matrix and midgut epithelia to reach the basal lamina and differentiate into an oocyst. The sporozoites produced in the oocyst are released into the hemolymph, and from there enter the salivary gland. During parasite development, wounds to midgut tissue and the basement membrane are produced. We describe the response of the different compartments where the parasite interacts with the mosquito. In the midgut, the response includes the expression of antimicrobial peptides, production of reactive oxygen species, and possible activation of midgut regenerative cells. In the basal membrane, wound repair mainly involves the production of molecules and the recruitment of hemocytes. We discuss the susceptibility to damage in tissues, and how the place and degree of damage may influence the differential response and the expression of damage associated molecular patterns (DAMPs). Knowledge about damage caused by parasites may lead to a deeper understanding of the relevance of tissue damage and the immune response it generates, as well as the origins and progression of infection in this insect-parasite interaction.

The Concise Guide to PHARMACOLOGY 2013/14: enzymes

The Concise Guide to PHARMACOLOGY 2013/14 provides concise overviews of the key properties of over 2000 human drug targets with their pharmacology, plus links to an open access knowledgebase of drug targets and their ligands (www.guidetopharmacology.org), which provides more detailed views of target and ligand properties. The full contents can be found at http://onlinelibrary.wiley.com/doi/10.1111/bph.12444/full. Enzymes are one of the seven major pharmacological targets into which the Guide is divided, with the others being G protein-coupled receptors, ligand-gated ion channels, ion channels, nuclear hormone receptors, catalytic receptors and transporters. These are presented with nomenclature guidance and summary information on the best available pharmacological tools, alongside key references and suggestions for further reading. A new landscape format has easy to use tables comparing related targets. It is a condensed version of material contemporary to late 2013, which is presented in greater detail and constantly updated on the website www.guidetopharmacology.org, superseding data presented in previous Guides to Receptors and Channels. It is produced in conjunction with NC-IUPHAR and provides the official IUPHAR classification and nomenclature for human drug targets, where appropriate. It consolidates information previously curated and displayed separately in IUPHAR-DB and the Guide to Receptors and Channels, providing a permanent, citable, point-in-time record that will survive database updates.

Antiepileptic drugs prevent changes in adenosine deamination during acute seizure episodes in adult zebrafish

Adenosine is an endogenous modulator of brain functions, which presents anticonvulsant properties. In addition, its levels can be increased during neural injury. The modulation of extracellular adenosine levels by ectonucleotidase and adenosine deaminase (ADA) activities may represent a key mechanism in the control of epileptogenesis. In the present study, we investigated the effects of acute seizure episodes and antiepileptic drug (AED) treatments on ectonucleotidases and ADA activities in adult zebrafish brain. Our data have demonstrated that pentylenetetrazole (PTZ)-induced seizures did not alter ATP, ADP, and AMP hydrolysis in brain membrane fractions. However, there was a significant increase on ecto-ADA and soluble ADA activities in PTZ-treated animals immediately after a clonus-like convulsion and loss of posture, which are typical behavioral changes observed in Stage 3. Furthermore, our results have demonstrated that AED pretreatments prevented the stimulatory effect promoted by PTZ exposure on ADA activities. The PTZ and AED treatments did not promote alterations on ADA gene expression. Interestingly, when exposed to PTZ, animals pretreated with AEDs showed longer latency to reach the clonus-like seizure status, which is an effect that matches the suppression of the increase of ADA activity promoted by the AEDs. These data suggest that the adenosine deamination could be involved in the control of seizure development in zebrafish and may be modulated by AED treatments.

Characterization of a gene coding for a putative adenosine deaminase-related growth factor by RNA interference in the basidiomycete Flammulina velutipes

A full-length cDNA coding for a putative adenosine deaminase (Fv-ada) was isolated from the basidiomycete Flammulina velutipes. Fv-ada encodes a polypeptide consisting of 537 amino acid residues, which has a consensus sequence conserved among adenosine deaminase-related growth factors (ADGF) found in several metazoa, including chordates and insects. Fv-ada transcript was detected at all stages of growth in dikaryotic F. velutipes cells, with a peak at the primordial stage. Heterologous expression of Fv-ada in the yeast Pichia pastoris produced recombinant Fv-ADA that catalyzed the conversion of adenosine to inosine. Dikaryotic mycelia from F. velutipes were transformed with the binary plasmid pFungiway-Fv-ada, which was designed to suppress the expression of Fv-ada through RNA interference. The growth rates of the resulting transformants were retarded in response to the degree of suppression, indicating that Fv-ada plays an important role in the mycelial growth of F. velutipes. These results suggested that ADGF could function as growth factors in fungi, as is seen in other eukaryotes.

PTZ-induced seizures inhibit adenosine deamination in adult zebrafish brain membranes

Adenosine exerts neuromodulatory functions with mostly inhibitory effects, being considered an endogenous anticonvulsant. The hydrolysis of ATP by ectonucleotidases is an important source of adenosine, and adenosine deaminase (ADA) contributes to the regulation of this nucleoside concentration through its deamination. In this study, we tested the effect of pentylenetetrazole (PTZ)-induced seizures on ectonucleotidase and ADA activities in adult zebrafish brain. Our results have demonstrated that PTZ treatments did not alter ectonucleotidase and ADA activities in membranes and soluble fraction, respectively. However, ecto-ADA activity was significantly decreased in brain membranes of animals exposed to 5mM and 15 mM PTZ treatments (22.4% and 29.5%, respectively) when compared to the control group. Semiquantitative RT-PCR analysis did not show significant changes after the PTZ exposure on ADA gene expression. The decreased adenosine deamination observed in this study suggests a modulation of extracellular adenosine levels during PTZ-induced seizures in zebrafish.

Immunological alterations mediated by adenosine during host-microbial interactions

Adenosine accumulates in inflammation and ischemia but it is more than an end-product of ATP catabolism. Signaling through different receptors with distinct, cell-specific cytoplasmic pathways, adenosine is now recognized as an inducible switch that regulates the immune system. By acting through the A(2A)AR, adenosine shapes T cell function, largely by conferring an anti-inflammatory tone on effector Th cells (Teff) and natural killer (NK)T cells. In contrast, both the A(2A)AR and A(2B)AR are expressed by antigen-presenting cells (APC) which have been shown to regulate innate responses and the transition to adaptive immunity. There is also emerging evidence that adenosine production is one mechanism that allows some pathogens as well as neoplasms to evade host defenses. This review discusses the immunoregulatory functions of adenosine and some of the interactions it may have in regulating host-microbial interactions.

Kinetic characterization and gene expression of adenosine deaminase in intact trophozoites of Trichomonas vaginalis

Trichomonas vaginalis is a parasite that resides in the human urogenital tract and causes trichomonosis, the most prevalent nonviral sexually transmitted disease. Nucleoside triphosphate diphosphohydrolase (NTPDase), which hydrolyzes extracellular di- and triphosphate nucleotides, and ecto-5'-nucleotidase, which hydrolyzes AMP, have been characterized in T. vaginalis. The aim of this study was to characterize the adenosine deaminase (ADA) activity in intact trophozoites of T. vaginalis. A strong inhibition in adenosine deamination was observed in the presence of calcium and magnesium, which was prevented by EDTA. The apparent K(M) value for adenosine was 1.13 ± 0.07mM. The calculated V(max) was 2.61 ± 0.054 nmol NH(3) min(-1) mg(-1) protein. Adenosine deamination was inhibited in the presence of erythro-9-(2-hydroxy-3-nonyl)adenine. Semi-quantitative reverse transcriptase-PCR experiments were performed and both ADA-related genes ada(125) and ada(231) mRNA were expressed, although ada(231) in higher quantity when compared with the ada(125) : α-tubulin ratio. Furthermore, a phylogenetic analysis showed that the T. vaginalis sequences formed a clade with Entamoeba histolytica and Dictyostelium discoideum sequences, and it strongly suggests homologous functions in the T. vaginalis genome. The presence of ADA activity in T. vaginalis may be important to modulate the adenosine/inosine levels during infection and, consequently, to maintain the anti-inflammatory properties through different nucleoside-signalling mechanisms.

Adenosine deaminase from Streptomyces coelicolor: recombinant expression, purification and characterization

The sequencing of the genome of Streptomyces coelicolor A3(2) identified seven putative adenine/adenosine deaminases and adenosine deaminase-like proteins, none of which have been biochemically characterized. This report describes recombinant expression, purification and characterization of SCO4901 which had been annotated in data bases as a putative adenosine deaminase. The purified putative adenosine deaminase gives a subunit Mr=48,400 on denaturing gel electrophoresis and an oligomer molecular weight of approximately 182,000 by comparative gel filtration. These values are consistent with the active enzyme being composed of four subunits with identical molecular weights. The turnover rate of adenosine is 11.5 s⁻¹ at 30 °C. Since adenine is deaminated ∼10³ slower by the enzyme when compared to that of adenosine, these data strongly show that the purified enzyme is an adenosine deaminase (ADA) and not an adenine deaminase (ADE). Other adenine nucleosides/nucleotides, including 9-β-D-arabinofuranosyl-adenine (ara-A), 5'-AMP, 5'-ADP and 5'-ATP, are not substrates for the enzyme. Coformycin and 2'-deoxycoformycin are potent competitive inhibitors of the enzyme with inhibition constants of 0.25 and 3.4 nM, respectively. Amino acid sequence alignment of ScADA with ADAs from other organisms reveals that eight of the nine highly conserved catalytic site residues in other ADAs are also conserved in ScADA. The only non-conserved residue is Asn317, which replaces Asp296 in the murine enzyme. Based on these data, it is suggested here that ADA and ADE proteins are divergently related enzymes that have evolved from a common α/β barrel scaffold to catalyze the deamination of different substrates, using a similar catalytic mechanism.

Pain-relieving prospects for adenosine receptors and ectonucleotidases

Adenosine receptor agonists have potent antinociceptive effects in diverse preclinical models of chronic pain. By contrast, the efficacy of adenosine and adenosine receptor agonists in treating pain in humans is unclear. Two ectonucleotidases that generate adenosine in nociceptive neurons were recently identified. When injected spinally, these enzymes have long-lasting adenosine A(1) receptor-dependent antinociceptive effects in inflammatory and neuropathic pain models. Furthermore, recent findings indicate that spinal adenosine A(2A) receptor activation can enduringly inhibit neuropathic pain symptoms. Collectively, these studies suggest the possibility of treating chronic pain in humans by targeting specific adenosine receptor subtypes in anatomically defined regions with agonists or with ectonucleotidases that generate adenosine.

Increased extracellular adenosine in Drosophila that are deficient in adenosine deaminase activates a release of energy stores leading to wasting and death

Extracellular adenosine is an important signaling molecule in neuromodulation, immunomodulation and hypoxia. Adenosine dysregulation can cause various pathologies, exemplified by a deficiency in adenosine deaminase in severe combined immunodeficiency. We have established a Drosophila model to study the effects of increased adenosine in vivo by mutating the main Drosophila adenosine deaminase-related growth factor (ADGF-A). Using a genetic screen, we show here that the increased extracellular adenosine in the adgf-a mutant is associated with hyperglycemia and impairment in energy storage. The adenosine works in this regard through the adenosine receptor as an anti-insulin hormone in parallel to adipokinetic hormone, a glucagon counterpart in flies. If not regulated properly, this action can lead to a loss of energy reserves (wasting) and death of the organism. Because adenosine signaling is associated with the immune response and the response to stress in general, our results mark extracellular adenosine as a good candidate signal involved in the wasting syndrome that accompanies various human pathologies.

Structural basis for the growth factor activity of human adenosine deaminase ADA2

Two distinct adenosine deaminases, ADA1 and ADA2, are found in humans. ADA1 has an important role in lymphocyte function and inherited mutations in ADA1 result in severe combined immunodeficiency. The recently isolated ADA2 belongs to the novel family of adenosine deaminase growth factors (ADGFs), which play an important role in tissue development. The crystal structures of ADA2 and ADA2 bound to a transition state analogue presented here reveal the structural basis of the catalytic/signaling activity of ADGF/ADA2 proteins. In addition to the catalytic domain, the structures discovered two ADGF/ADA2-specific domains of novel folds that mediate the protein dimerization and binding to the cell surface receptors. This complex architecture is in sharp contrast with that of monomeric single domain ADA1. An extensive glycosylation and the presence of a conserved disulfide bond and a signal peptide in ADA2 strongly suggest that ADA2, in contrast to ADA1, is specifically designed to act in the extracellular environment. The comparison of catalytic sites of ADA2 and ADA1 demonstrates large differences in the arrangement of the substrate-binding pockets. These structural differences explain the substrate and inhibitor specificity of adenosine deaminases and provide the basis for a rational design of ADA2-targeting drugs to modulate the immune system responses in pathophysiological conditions.

A proteomic analysis of Helicoverpa armigera adults after exposure to UV light irradiation

Ultraviolet (UV) light (blacklight), which emits UV in the range of 320-400nm, has been used worldwide in light trapping of insect pests. To gain a better understanding of the response of Helicoverpa armigera adults to UV light irradiation, we carried out a comparative proteomic analysis. Three-day-old adults were exposed to UV light for 1h. Total proteins were extracted and separated by two-dimensional gel electrophoresis. More than 1200 protein spots were reproducibly detected, including 12 that were more abundant and 21 less abundant. Mass spectrometry analysis and database searching helped us to identify 29 differentially abundant proteins. The identified proteins were categorized into several functional groups including signal transduction, RNA processing, protein processing, stress response, metabolisms, and cytoskeleton structure, etc. This study is the first analysis of differentially expressed proteins in phototactic insects under UV light irradiation conditions and gives new insights into the adaptation mechanisms responsive to UV light irradiation stress.

Hydrolytic cleavage of N6-substituted adenine derivatives by eukaryotic adenine and adenosine deaminases

Homogeneous adenine deaminases (EC 3.5.4.2) from the yeasts Saccharomyces cerevisiae and Schizosaccharomyces pombe and a putative ADA (adenosine deaminase; EC 3.5.4.4) from Arabidopsis thaliana were obtained for the first time as purified recombinant proteins by molecular cloning of the corresponding genes and their overexpression in Escherichia coli. The enzymes showed comparable molecular properties with well-known mammalian ADAs, but exhibited much lower k(cat) values. Adenine was the most favoured substrate for the yeast enzymes, whereas the plant enzyme showed only very low activities with either adenine, adenosine, AMP or ATP. Interestingly, the yeast enzymes also hydrolysed N6-substituted adenines from cytokinins, a group of plant hormones, cleaving them to inosine and the corresponding side chain amine. The hydrolytic cleavage of synthetic cytokinin 2,6-di-substituted analogues that are used in cancer therapy, such as olomoucine, roscovitine and bohemine, was subsequently shown for a reference sample of human ADA1. ADA1, however, showed a different reaction mechanism to that of the yeast enzymes, hydrolysing the compounds to an adenine derivative and a side chain alcohol. The reaction products were identified using reference compounds on HPLC coupled to UV and Q-TOF (quadrupole-time-of-flight) detectors.The ADA1 activity may constitute the debenzylation metabolic route already described for bohemine and, as a consequence, it may compromise the physiological or therapeutic effects of exogenously applied cytokinin derivatives.

Kinetic characterization of adenosine deaminase activity in zebrafish (Danio rerio) brain

Adenosine deaminase (ADA; EC 3.5.4.4) activity is responsible for cleaving adenosine to inosine. In this study we described the biochemical properties of adenosine deamination in soluble and membrane fractions of zebrafish (Danio rerio) brain. The optimum pH for ADA activity was in the range of 6.0-7.0 in soluble fraction and reached 5.0 in brain membranes. A decrease of 31.3% on adenosine deamination in membranes was observed in the presence of 5 mM Zn(2+), which was prevented by 5 mM EDTA. The apparent K(m) values for adenosine deamination were 0.22+/-0.03 and 0.19+/-0.04 mM for soluble and membrane fractions, respectively. The apparent V(max) value for soluble ADA activity was 12.3+/-0.73 nmol NH(3) min(-1) mg(-1) of protein whereas V(max) value in brain membranes was 17.5+/-0.51 nmol NH(3) min(-1) mg(-1) of protein. Adenosine and 2'-deoxyadenosine were deaminated in higher rates when compared to guanine nucleosides in both fractions. Furthermore, a significant inhibition on adenosine deamination in both soluble and membrane fractions was observed in the presence of 0.1 mM of erythro-9-(2-hydroxy-3-nonyl)adenine (EHNA). The presence of ADA activity in zebrafish brain may be important to regulate the adenosine/inosine levels in the CNS of this species.

The extracellular adenosine deaminase growth factor, ADGF/CECR1, plays a role in Xenopus embryogenesis via the adenosine/P1 receptor

Adenosine deaminase-related growth factors (ADGF), also known as CECR1 in vertebrates, are a novel family of growth factors with sequence similarity to classical cellular adenosine deaminase. Although genes for ADGF/CECR1 have been identified in both invertebrates as well as vertebrates, their in vivo functions in vertebrates remain unknown. We isolated cDNA clones for two cerc 1s from Xenopus laevis. Both recombinant Xenopus CECR1s exhibited adenosine deaminase and growth factor activity, and the adenosine deaminase activity was found to be indispensable for growth factor activity. The Xenopus cerc 1s are expressed in the somites, pronephros, eyes, cement gland, neural tube, and neural floor plate of the embryos. Knock-down of these two genes using morpholino oligonucleotides caused a reduction in the body size and abnormalities of the body axis in the Xenopus embryos, accompanied by selective changes in the expression of developmental marker genes. Injection of adenosine, agonists for adenosine/P1 receptors, or adenosine deaminase inhibitor into late gastrula archenteron embryos resulted in developmental defects similar to those caused by morpholino oligonucleotide injection. These results show, for the first time, the involvement of CECR1s via the adenosine/P1 receptors in vertebrate embryogenesis via regulation of extracellular adenosine concentrations.

Adenosine deaminase-related genes: molecular identification, tissue expression pattern and truncated alternative splice isoform in adult zebrafish (Danio rerio)

Adenosine deaminase (ADA) is responsible for cleaving the neuromodulator adenosine to inosine. Two members of ADA subfamilies, known as ADA1 and ADA2, were described and evidence demonstrated another similar protein group named ADAL (adenosine deaminase "like"). Although the identification of ADA members seems to be consistent, the expression profile of ADA1, ADA2 and ADAL genes in zebrafish has not yet been reported. The aim of the present study was to map the expression pattern of ADA-related genes in various tissues of adult zebrafish (Danio rerio). An extensive search on zebrafish genome followed by a phylogenetic analysis confirmed the presence of distinct ADA-related genes (ADA1, ADAL and two orthologous genes of ADA2). Specific primers for each ADA member were designed, optimized semi-quantitative RT-PCR experiments were conducted and the relative amount of transcripts was determined. The tissue samples (brain, gills, heart, liver, skeletal muscle and kidney) were collected and the expression of ADA1, ADAL and ADA2 genes was characterized. ADA1 had a similar expression pattern, whereas ADAL was less expressed in the heart. The highest relative amount of ADA2-1 transcripts was observed in the brain, liver and gills and it was less expressed in the heart. RT-PCR assays revealed that the other ADA2 form (ADA2-2) was expressed ubiquitously and at comparable levels in zebrafish tissues. The strategy adopted also allowed the identification of an ADA2-1 truncated alternative splice isoform (ADA2-1/T), which was expressed at different intensities. These findings demonstrated the existence of different ADA-related genes, their distinct expression pattern and a truncated ADA2-1 isoform, which suggest a high degree of complexity in zebrafish adenosinergic system.

AMINOHYDROLASES ACTING ON ADENINE, ADENOSINE AND THEIR DERIVATIVES

BACKGROUND

Adenine and adenosine-acting aminohydrolases are important groups of enzymes responsible for the metabolic salvage of purine compounds. Several subclasses of these enzymes have been described and given current knowledge of the full genome sequences of many organisms, it is possible to identify genes encoding these enzymes and group them according to their primary structure.

METHODS AND RESULTS

This article is a short overview of the enzymes classified as adenine and adenosine deaminase. It summarises knowledge of their occurrence, genetic basis and their catalytic and structural properties.

CONCLUSIONS

These enzymes are constitutive components of purine metabolism and their impairment may cause serious medical disorders. In humans, adenosine deaminase deficiency is linked to severe combined immunodeficiency and as such the enzyme has been approved for the first gene therapy trial. The role of these enzymes in plants is unclear, since the activity was has not been detected in extracts and putative genes have not been yet cloned and analyzed. A literature search and amino acid identity comparison show that Ascomycetes contain only adenine deaminase, but not adenosine deaminase, despite the fact that corresponding genes are annotated in databases as the adenosine cleaving enzymes because they share the same conserved domain.

Molecular characterization of MbADGF, a novel member of the adenosine deaminase-related growth factor in the cabbage armyworm, Mamestra brassicae: the functional roles in the midgut cell proliferation

To clarify the functional mechanism of the adenosine deaminase-related growth factor (ADGF) particularly in the regulation of insect development, the cDNA encoding a homologue of ADGF proteins was cloned from the cabbage armyworm, Mamestra brassicae, named MbADGF. The purified MbADGF recombinant protein stimulated cell proliferation in a dose-dependent manner of SES-MaBr-4 and NIAS-MaBr-93 cell lines that were derived from fat bodies and haemocytes of M. brassicae. The adenosine deaminase activity of MbADGF was detected using adenosine and 2'-deoxyadenosine as substrates. Northern analysis demonstrated that during the larval development the level of MbADGF in the midgut increased. In situ hybridization showed that MbADGF mRNA was expressed in midgut goblet cells and in the apical cytoplasm of columnar cells, which suggests that MbADGF protein may execute its adenosine deaminase activity at the apical cytoplasm of columnar cells to convert adenosine into inosine.

Genome survey sequencing of the wine spoilage yeast Dekkera (Brettanomyces) bruxellensis

The hemiascomycete yeast Dekkera bruxellensis, also known as Brettanomyces bruxellensis, is a major cause of wine spoilage worldwide. Wines infected with D. bruxellensis develop distinctive, unpleasant aromas due to volatile phenols produced by this species, which is highly ethanol tolerant and facultatively anaerobic. Despite its importance, however, D. bruxellensis has been poorly genetically characterized until now. We performed genome survey sequencing of a wine strain of D. bruxellensis to obtain 0.4x coverage of the genome. We identified approximately 3,000 genes, whose products averaged 49% amino acid identity to their Saccharomyces cerevisiae orthologs, with similar intron contents. Maximum likelihood phylogenetic analyses suggest that the relationship between D. bruxellensis, S. cerevisiae, and Candida albicans is close to a trichotomy. The estimated rate of chromosomal rearrangement in D. bruxellensis is slower than that calculated for C. albicans, while its rate of amino acid evolution is somewhat higher. The proteome of D. bruxellensis is enriched for transporters and genes involved in nitrogen and lipid metabolism, among other functions, which may reflect adaptations to its low-nutrient, high-ethanol niche. We also identified an adenyl deaminase gene that has high similarity to a gene in bacteria of the Burkholderia cepacia species complex and appears to be the result of horizontal gene transfer. These data provide a resource for further analyses of the population genetics and evolution of D. bruxellensis and of the genetic bases of its physiological capabilities.

Involvement of insect-derived growth factor (IDGF) in the cell growth of an embryonic cell line of flesh fly

Insect-derived growth factor (IDGF) is the first adenosine deaminase-related growth factor (ADGF) purified from the conditioned medium of NIH-Sape-4, an embryonic cell line of Sarcophaga peregrina (flesh fly). Here we show the requirement of IDGF for the growth of NIH-Sape-4 cells. Growth factor activity was abolished by adsorption of IDGF from the conditioned medium of NIH-Sape-4 cells. In addition, knockdown of IDGF gene expression by RNA interference (RNAi) significantly reduced IDGF secretion from the cells following cell growth inhibition. The IDGF gene was strongly expressed in the hemocytes, and IDGF increased the viability of the larval hemocytes. These data provide evidence that IDGF is required for the growth of NIH-Sape-4 cells and possibly for hemocyte viability.