-
Biochimica Et Biophysica Acta Aug 2014WWOX was cloned as a putative tumor suppressor gene mapping to chromosomal fragile site FRA16D. Deletions affecting WWOX accompanied by loss of expression are frequent... (Review)
Review
WWOX was cloned as a putative tumor suppressor gene mapping to chromosomal fragile site FRA16D. Deletions affecting WWOX accompanied by loss of expression are frequent in various epithelial cancers. Translocations and deletions affecting WWOX are also common in multiple myeloma and are associated with worse prognosis. Metanalysis of gene expression datasets demonstrates that low WWOX expression is significantly associated with shorter relapse-free survival in ovarian and breast cancer patients. Although somatic mutations affecting WWOX are not frequent, analysis of TCGA tumor datasets led to identifying 44 novel mutations in various tumor types. The highest frequencies of mutations were found in head and neck cancers and uterine and gastric adenocarcinomas. Mouse models of gene ablation led us to conclude that Wwox does not behave as a highly penetrant, classical tumor suppressor gene since its deletion is not tumorigenic in most models and its role is more likely to be of relevance in tumor progression rather than in initiation. Analysis of signaling pathways associated with WWOX expression confirmed previous in vivo and in vitro observations linking WWOX function with the TGFβ/SMAD and WNT signaling pathways and with specific metabolic processes. Supporting these conclusions recently we demonstrated that indeed WWOX behaves as a modulator of TGFβ/SMAD signaling by binding and sequestering SMAD3 in the cytoplasmic compartment. As a consequence progressive loss of WWOX expression in advanced breast cancer would contribute to the pro-metastatic effects resulting from TGFβ/SMAD3 hyperactive signaling in breast cancer. Recently, GWAS and resequencing studies have linked the WWOX locus with familial dyslipidemias and metabolic syndrome related traits. Indeed, gene expression studies in liver conditional KO mice confirmed an association between WWOX expression and lipid metabolism. Finally, very recently the first human pedigrees with probands carrying homozygous germline loss of function WWOX mutations have been identified. These patients are characterized by severe CNS related pathology that includes epilepsy, ataxia and mental retardation. In summary, WWOX is a highly conserved and tightly regulated gene throughout evolution and when defective or deregulated the consequences are important and deleterious as demonstrated by its association not only with poor prognosis in cancer but also with other important human pathologies such as metabolic syndrome and CNS related pathologic conditions.
Topics: Animals; Central Nervous System Diseases; Evolution, Molecular; Humans; Metabolic Syndrome; Mice; Mutation; Neoplasms; Oxidoreductases; Quantitative Trait Loci; Tumor Suppressor Proteins; WW Domain-Containing Oxidoreductase
PubMed: 24932569
DOI: 10.1016/j.bbcan.2014.06.001 -
Scientific Reports Sep 2023Propionate is a microbial metabolite formed in the gastrointestinal tract, and it affects host physiology as a source of energy and signaling molecule. Despite the...
Propionate is a microbial metabolite formed in the gastrointestinal tract, and it affects host physiology as a source of energy and signaling molecule. Despite the importance of propionate, the biochemical pathways responsible for its formation are not clear in all microbes. For the succinate pathway used during fermentation, a key enzyme appears to be missing-one that oxidizes ferredoxin and reduces NAD. Here we show that Rnf [ferredoxin-NAD oxidoreductase (Na-transporting)] is this key enzyme in two abundant bacteria of the rumen (Prevotella brevis and Prevotella ruminicola). We found these bacteria form propionate, succinate, and acetate with the classic succinate pathway. Without ferredoxin:NAD oxidoreductase, redox cofactors would be unbalanced; it would produce almost equal excess amounts of reduced ferredoxin and oxidized NAD. By combining growth experiments, genomics, proteomics, and enzyme assays, we point to the possibility that these bacteria solve this problem by oxidizing ferredoxin and reducing NAD with Rnf [ferredoxin-NAD oxidoreductase (Na-transporting)]. Genomic and phenotypic data suggest many bacteria may use Rnf similarly. This work shows the ferredoxin:NAD oxidoreductase activity of Rnf is important to propionate formation in Prevotella species and other bacteria from the environment, and it provides fundamental knowledge for manipulating fermentative propionate production.
Topics: Animals; Ferredoxins; Propionates; NAD; Fermentation; Glucose; Oxidation-Reduction; Oxidoreductases; Succinates; Succinic Acid; Prevotella
PubMed: 37777597
DOI: 10.1038/s41598-023-43282-9 -
Cytogenetic and Genome Research 2016FHIT, located at FRA3B, is one of the most commonly deleted genes in human cancers, and loss of FHIT protein is one of the earliest events in cancer initiation. However,... (Review)
Review
FHIT, located at FRA3B, is one of the most commonly deleted genes in human cancers, and loss of FHIT protein is one of the earliest events in cancer initiation. However, location of FHIT at a chromosomal fragile site, a locus prone to breakage and gap formation under even mild replication stress, has encouraged claims that FHIT loss is a passenger event in cancers. We summarize accumulated evidence that FHIT protein functions as a genome "caretaker" required to protect the stability of genomes of normal cells of most tissues from agents causing intrinsic and extrinsic DNA damage. FHIT loss leads to intracellular replication stress and subsequent genome instability, which provides an opportunistic mutational landscape in preneoplasias for selection of a variety of other cancer-driving mutations. We also review evidence showing that FHIT loss leads to enhanced activation of other common fragile sites, including the FRA16D/WWOX locus, and creates optimal single-stranded DNA substrates for the hypermutator enzyme, APOBEC3B.
Topics: Acid Anhydride Hydrolases; Chromosome Fragile Sites; Genes, p53; Genomic Instability; Humans; Mutation; Neoplasm Proteins; Neoplasms; Oxidoreductases; Precancerous Conditions; Tumor Suppressor Proteins; WW Domain-Containing Oxidoreductase
PubMed: 28199992
DOI: 10.1159/000455753 -
The ISME Journal Apr 2023Ammonia oxidation, as the first step of nitrification, constitutes a critical process in the global nitrogen cycle. However, fundamental knowledge of its key enzyme, the...
Ammonia oxidation, as the first step of nitrification, constitutes a critical process in the global nitrogen cycle. However, fundamental knowledge of its key enzyme, the copper-dependent ammonia monooxygenase, is lacking, in particular for the environmentally abundant ammonia-oxidizing archaea (AOA). Here the structure of the enzyme is investigated by blue-native gel electrophoresis and proteomics from native membrane complexes of two AOA. Besides the known AmoABC subunits and the earlier predicted AmoX, two new protein subunits, AmoY and AmoZ, were identified. They are unique to AOA, highly conserved and co-regulated, and their genes are linked to other AMO subunit genes in streamlined AOA genomes. Modeling and in-gel cross-link approaches support an overall protomer structure similar to the distantly related bacterial particulate methane monooxygenase but also reveals clear differences in extracellular domains of the enzyme. These data open avenues for further structure-function studies of this ecologically important nitrification complex.
Topics: Archaea; Oxidoreductases; Nitrification; Native Polyacrylamide Gel Electrophoresis; Phylogeny; Gene Expression
PubMed: 36721060
DOI: 10.1038/s41396-023-01367-3 -
Plant Physiology and Biochemistry : PPB Jan 2016L-Ascorbic acid (ascorbate, AsA, vitamin C) is essential for animal and plant health. Despite our dependence on fruits and vegetables to fulfill our requirement for this... (Review)
Review
L-Ascorbic acid (ascorbate, AsA, vitamin C) is essential for animal and plant health. Despite our dependence on fruits and vegetables to fulfill our requirement for this vitamin, the metabolic network leading to its formation in plants is just being fully elucidated. There is evidence supporting the operation of at least four biosynthetic pathways leading to AsA formation in plants. These routes use D-mannose/L-galactose, L-gulose, D-galacturonate, and myo-inositol as the main precursors. This review focuses on aldonolactone oxidoreductases, a subgroup of the vanillyl alcohol oxidase (VAO; EC 1.1.3.38) superfamily, enzymes that catalyze the terminal step in AsA biosynthesis in bacteria, protozoa, animals, and plants. In this report, we review the properties of well characterized aldonolactone oxidoreductases to date. A shared feature in these proteins is the presence of a flavin cofactor as well as a thiol group. The flavin cofactor in many cases is bound to the N terminus of the enzymes or to a recently discovered HWXK motif in the C terminus. The binding between the flavin moiety and the protein can be either covalent or non-covalent. Substrate specificity and subcellular localization differ among the isozymes of each kingdom. All oxidases among these enzymes possess dehydrogenase activity, however, exclusive dehydrogenases are also found. We also discuss recent evidence indicating that plants have both L-gulono-1,4-lactone oxidases and L-galactono-1,4-lactone dehydrogenases involved in AsA biosynthesis.
Topics: Alcohol Oxidoreductases; Amino Acid Sequence; Ascorbic Acid; Coenzymes; Flavins; Galactose; Lactones; Mannose; Molecular Sequence Data; Oxidation-Reduction; Oxidoreductases; Plants; Recombinant Proteins; Sequence Alignment; Substrate Specificity; Sugar Acids
PubMed: 26696130
DOI: 10.1016/j.plaphy.2015.11.017 -
Oncology Reports Mar 2023Sorafenib is a targeted drug for hepatocellular carcinoma (HCC), however, its efficacy is limited. Nuclear factor erythroid 2‑related factor 2 (Nrf2) contributes to...
Sorafenib is a targeted drug for hepatocellular carcinoma (HCC), however, its efficacy is limited. Nuclear factor erythroid 2‑related factor 2 (Nrf2) contributes to sorafenib resistance. The present study investigated camptothecin (CPT) as a Nrf2 inhibitor to sensitize HCC to sorafenib. The effect of CPT on sorafenib sensitivity in HCC was assessed using H22 mice model (n=32) and VX2 rabbit models (n=32), which were sorted into four treatment groups. The expression levels of Nrf2, its downstream genes, including heme oxygenases‑1 (HO‑1) and NAD(P)H quinone oxidoreductase 1 (NQO1), and the epithelial‑mesenchymal transition markers Snail and N‑cadherin in tumors were determined using immunohistochemical staining and western blotting. Magnetic resonance imaging was used to monitor changes in tumor microcirculation and activity before and after treatment. Mouse body weights, liver and kidney function were monitored to evaluate the safety of combined therapy. The results revealed that the mean tumor size of the combined group was significantly smaller than that of sorafenib group for both models. The expression levels of Nrf2, heme oxygenase‑1, NAD(P)H quinone oxidoreductase 1, Snail, and N‑cadherin in the sorafenib group were significantly higher than control group (P<0.05). However, the expression levels of these genes were decreased in the combined group (P<0.05). Microcirculation perfusion and tumor activity in the combined group were also lower than sorafenib group. There were no significant differences in mouse body weight or liver and kidney function among the four groups. In summary, CPT is a Nrf2 inhibitor that could enhance the efficacy of sorafenib against HCC.
Topics: Animals; Mice; Rabbits; Carcinoma, Hepatocellular; Sorafenib; NF-E2-Related Factor 2; Liver Neoplasms; NAD; Camptothecin; Quinones; Oxidoreductases; Drug Resistance, Neoplasm; Cell Line, Tumor
PubMed: 36734286
DOI: 10.3892/or.2023.8492 -
Protein Science : a Publication of the... Apr 2016The Gfo/Idh/MocA protein family contains a number of different proteins, which almost exclusively consist of NAD(P)-dependent oxidoreductases that have a diverse set of... (Review)
Review
The Gfo/Idh/MocA protein family contains a number of different proteins, which almost exclusively consist of NAD(P)-dependent oxidoreductases that have a diverse set of substrates, typically pyranoses. In this study, to clarify common structural features that would contribute to their function, the available crystal structures of the members of this family have been analyzed. Despite a very low sequence identity, the central features of the three-dimensional structures of the proteins are surprisingly similar. The members of the protein family have a two-domain structure consisting of a N-terminal nucleotide-binding domain and a C-terminal α/β-domain. The C-terminal domain contributes to the substrate binding and catalysis, and contains a βα-motif with a central α-helix carrying common essential amino acid residues. The β-sheet of the α/β-domain contributes to the oligomerization in most of the proteins in the family.
Topics: Binding Sites; Catalysis; Catalytic Domain; Crystallography, X-Ray; Models, Molecular; Multigene Family; Oxidoreductases; Protein Multimerization; Protein Structure, Secondary
PubMed: 26749496
DOI: 10.1002/pro.2877 -
The Journal of Biological Chemistry May 2022Oxidation of malate to oxaloacetate, catalyzed by either malate dehydrogenase (Mdh) or malate quinone oxidoreductase (Mqo), is a critical step of the tricarboxylic acid...
Oxidation of malate to oxaloacetate, catalyzed by either malate dehydrogenase (Mdh) or malate quinone oxidoreductase (Mqo), is a critical step of the tricarboxylic acid cycle. Both Mqo and Mdh are found in most bacterial genomes, but the level of functional redundancy between these enzymes remains unclear. A bioinformatic survey revealed that Mqo was not as widespread as Mdh in bacteria but that it was highly conserved in mycobacteria. We therefore used mycobacteria as a model genera to study the functional role(s) of Mqo and its redundancy with Mdh. We deleted mqo from the environmental saprophyte Mycobacterium smegmatis, which lacks Mdh, and found that Mqo was essential for growth on nonfermentable carbon sources. On fermentable carbon sources, the Δmqo mutant exhibited delayed growth and lowered oxygen consumption and secreted malate and fumarate as terminal end products. Furthermore, heterologous expression of Mdh from the pathogenic species Mycobacterium tuberculosis shortened the delayed growth on fermentable carbon sources and restored growth on nonfermentable carbon sources at a reduced growth rate. In M. tuberculosis, CRISPR interference of either mdh or mqo expression resulted in a slower growth rate compared to controls, which was further inhibited when both genes were knocked down simultaneously. These data reveal that exergonic Mqo activity powers mycobacterial growth under nonenergy limiting conditions and that endergonic Mdh activity complements Mqo activity, but at an energetic cost for mycobacterial growth. We propose Mdh is maintained in slow-growing mycobacterial pathogens for use under conditions such as hypoxia that require reductive tricarboxylic acid cycle activity.
Topics: Bacterial Proteins; Carbon; Citric Acid Cycle; Malate Dehydrogenase; Malates; Mycobacterium smegmatis; Oxaloacetic Acid; Oxidoreductases
PubMed: 35337802
DOI: 10.1016/j.jbc.2022.101859 -
The Journal of Biological Chemistry Aug 2022Microaerophilic pathogens such as Giardia lamblia, Entamoeba histolytica, and Trichomonas vaginalis have robust oxygen consumption systems to detoxify oxygen and...
Microaerophilic pathogens such as Giardia lamblia, Entamoeba histolytica, and Trichomonas vaginalis have robust oxygen consumption systems to detoxify oxygen and maintain intracellular redox balance. This oxygen consumption results from HO-forming NADH oxidase (NOX) activity of two distinct flavin-containing systems: HO-forming NOXes and multicomponent flavodiiron proteins (FDPs). Neither system is membrane bound, and both recycle NADH into oxidized NAD while simultaneously removing O from the local environment. However, little is known about the specific contributions of these systems in T. vaginalis. In this study, we use bioinformatics and biochemical analyses to show that T. vaginalis lacks a NOX-like enzyme and instead harbors three paralogous genes (FDPF1-3), each encoding a natural fusion product between the N-terminal FDP, central rubredoxin (Rb), and C-terminal NADH:Rb oxidoreductase domains. Unlike a "stand-alone" FDP that lacks Rb and oxidoreductase domains, this natural fusion protein with fully populated flavin redox centers directly accepts reducing equivalents of NADH to catalyze the four-electron reduction of oxygen to water within a single polypeptide with an extremely high turnover. Furthermore, using single-particle cryo-EM, we present structural insights into the spatial organization of the FDP core within this multidomain fusion protein. Together, these results contribute to our understanding of systems that allow protozoan parasites to maintain optimal redox balance and survive transient exposure to oxic conditions.
Topics: Flavins; NAD; NADH, NADPH Oxidoreductases; Oxidation-Reduction; Oxidoreductases; Oxygen; Rubredoxins; Trichomonas vaginalis; Water
PubMed: 35780837
DOI: 10.1016/j.jbc.2022.102210 -
Chemical Reviews Mar 2018A growing subset of metalloenzymes activates dioxygen with nonheme diiron active sites to effect substrate oxidations that range from the hydroxylation of methane and... (Review)
Review
A growing subset of metalloenzymes activates dioxygen with nonheme diiron active sites to effect substrate oxidations that range from the hydroxylation of methane and the desaturation of fatty acids to the deformylation of fatty aldehydes to produce alkanes and the six-electron oxidation of aminoarenes to nitroarenes in the biosynthesis of antibiotics. A common feature of their reaction mechanisms is the formation of O adducts that evolve into more reactive derivatives such as diiron(II,III)-superoxo, diiron(III)-peroxo, diiron(III,IV)-oxo, and diiron(IV)-oxo species, which carry out particular substrate oxidation tasks. In this review, we survey the various enzymes belonging to this unique subset and the mechanisms by which substrate oxidation is carried out. We examine the nature of the reactive intermediates, as revealed by X-ray crystallography and the application of various spectroscopic methods and their associated reactivity. We also discuss the structural and electronic properties of the model complexes that have been found to mimic salient aspects of these enzyme active sites. Much has been learned in the past 25 years, but key questions remain to be answered.
Topics: Catalytic Domain; Crystallography, X-Ray; Iron; Oxidation-Reduction; Oxidoreductases; Oxygen; X-Ray Absorption Spectroscopy
PubMed: 29400961
DOI: 10.1021/acs.chemrev.7b00457