RESUMO
In many animals, progression of developmental stages is temporally controlled by steroid hormones. In Drosophila, the level of ecdysone titer oscillates and developmental stage transitions, such as larval molting and metamorphosis, are induced at each of ecdysone peaks. Ecdysone titer also peaks at the stage of mid-embryogenesis and the embryonic ecdysone is necessary for morphogenesis of several organs, although the regulatory mechanisms of embryonic organogenesis dependent on ecdysone signaling are still open questions. In this study, we find that absence or interruption of embryonic ecdysone signaling caused multiple defects in the tracheal system, including decrease in luminal protein deposition, uneven dilation of the dorsal trunk and loss of terminal branches. We also reveal that an ecdysone-inducible gene polished rice (pri) is essential for tip cell fate decision in dorsal branches. As over-expression of pri can restore the defects caused by disturbance of ecdysone biosynthesis, pri functions as one of the major mediators of embryonic ecdysone signal in tracheogenesis. These results demonstrate that ecdysone and its downstream target pri play essential roles in tracheal development by modulating cell fate decision.
Assuntos
Proteínas de Drosophila/metabolismo , Drosophila melanogaster/embriologia , Drosophila melanogaster/metabolismo , Ecdisona/metabolismo , Embrião não Mamífero/metabolismo , Organogênese , Transaldolase/metabolismo , Animais , Diferenciação Celular , Linhagem da Célula , Proteínas de Drosophila/genética , Regulação da Expressão Gênica no Desenvolvimento , Modelos Biológicos , Mutação/genética , Fenótipo , Traqueia/citologia , Traqueia/embriologia , Traqueia/metabolismo , Transaldolase/genéticaRESUMO
The genomes of most cellulolytic clostridia do not contain genes annotated as transaldolase. Therefore, for assimilating pentose sugars or for generating C5 precursors (such as ribose) during growth on other (non-C5) substrates, they must possess a pathway that connects pentose metabolism with the rest of metabolism. Here we provide evidence that for this connection cellulolytic clostridia rely on the sedoheptulose 1,7-bisphosphate (SBP) pathway, using pyrophosphate-dependent phosphofructokinase (PPi-PFK) instead of transaldolase. In this reversible pathway, PFK converts sedoheptulose 7-phosphate (S7P) to SBP, after which fructose-bisphosphate aldolase cleaves SBP into dihydroxyacetone phosphate and erythrose 4-phosphate. We show that PPi-PFKs of Clostridium thermosuccinogenes and Clostridium thermocellum indeed can convert S7P to SBP, and have similar affinities for S7P and the canonical substrate fructose 6-phosphate (F6P). By contrast, (ATP-dependent) PfkA of Escherichia coli, which does rely on transaldolase, had a very poor affinity for S7P. This indicates that the PPi-PFK of cellulolytic clostridia has evolved the use of S7P. We further show that C. thermosuccinogenes contains a significant SBP pool, an unusual metabolite that is elevated during growth on xylose, demonstrating its relevance for pentose assimilation. Last, we demonstrate that a second PFK of C. thermosuccinogenes that operates with ATP and GTP exhibits unusual kinetics toward F6P, as it appears to have an extremely high degree of cooperative binding, resulting in a virtual on/off switch for substrate concentrations near its K½ value. In summary, our results confirm the existence of an SBP pathway for pentose assimilation in cellulolytic clostridia.
Assuntos
Clostridiales/genética , Clostridium thermocellum/genética , Frutose-Bifosfato Aldolase/genética , Via de Pentose Fosfato/genética , Fosfofrutoquinase-1/genética , Clostridiales/enzimologia , Clostridium thermocellum/enzimologia , Fosfato de Di-Hidroxiacetona/genética , Fosfato de Di-Hidroxiacetona/metabolismo , Escherichia coli/enzimologia , Frutose-Bifosfato Aldolase/metabolismo , Frutosefosfatos/metabolismo , Cinética , Pentoses/biossíntese , Pentoses/metabolismo , Fosfofrutoquinase-1/metabolismo , Fosfotransferases/metabolismo , Ribose/biossíntese , Ribose/metabolismo , Fosfatos Açúcares/metabolismo , Transaldolase/genética , Transaldolase/metabolismo , Xilose/biossíntese , Xilose/metabolismoRESUMO
PURPOSE: Identification of effective biomarkers for the benefit of endocrine treatment and understanding the molecular pathways that contribute to the development of resistance are of crucial importance to the management of luminal breast cancer. The amino acid transporter SLC1A5 has emerging importance as a prognostic marker and potential therapeutic target in various types of cancer. This study aims to investigate its role in luminal breast cancer as a potential predictive marker for endocrine treatment. METHODS: SLC1A5 expression was assessed at the transcriptomic and proteomic levels in large, well-characterized cohorts of luminal breast cancer. The sensitivity to endocrine therapy after SLC1A5 knockdown was investigated in vitro, using MCF7 and MDA-MB-175 cell lines. Bioinformatic analyses were performed to study the interacting networks of SLC1A5 and to identify a key co-expressed gene with SLC1A5. RESULTS: Here, we showed that patients with tumors that highly expressed SLC1A5 associated with a high risk of relapse after endocrine treatment. In vitro, depletion of SLC1A5 increases the sensitivity of luminal breast cancer cells to tamoxifen. TALDO1 was identified as key co-expressed gene with SLC1A5, and in vitro knockdown of SLC1A5 showed reduction in TALDO1 expression. Indeed, TALDO1 was associated with poor clinical outcomes in patients who were subject to endocrine therapy. CONCLUSION: These findings suggest that metabolic alterations, particularly the interaction between the key amino acid transporter SLC1A5 and metabolic enzyme TALDO1, could affect the sensitivity of endocrine therapy. This study demonstrated the prognostic value of both SLC1A5 and TALDO1 as biomarkers in luminal breast cancer.
Assuntos
Sistema ASC de Transporte de Aminoácidos/genética , Neoplasias da Mama , Antígenos de Histocompatibilidade Menor/genética , Receptores de Estrogênio , Transaldolase/genética , Antineoplásicos Hormonais/farmacologia , Antineoplásicos Hormonais/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Recidiva Local de Neoplasia , Proteômica , Receptores de Estrogênio/genética , Receptores de Estrogênio/metabolismo , Tamoxifeno/uso terapêuticoRESUMO
OBJECTIVE: Erythritol (1,2,3,4-butanetetrol) is a 4-carbon sugar alcohol that occurs in nature as a metabolite or storage compound. In this study, a multiple gene integration strategy was employed to enhance erythritol production in Y. lipolytica. RESULTS: The effects on the production of erythritol in Y. lipolytica of seven key genes involved in the erythritol synthesis pathway were evaluated individually, among which transketolase (TKL1) and transaldolase (TAL1) showed important roles in enhancing erythritol production. The combined overexpression of four genes (GUT1, TPI1, TKL1, TAL1) and disruption of the EYD1 gene (encoding erythritol dehydrogenase), resulted in produce approximately 40 g/L erythritol production from glycerol. Further enhanced erythritol synthesis was obtained by overexpressing the RKI1 gene (encoding ribose 5-phosphate isomerase) and the AMPD gene (encoding AMP deaminase), indicating for the first time that these two genes are also related to the enhancement of erythritol production in Y. lipolytica. CONCLUSIONS: A combined gene overexpression strategy was developed to efficiently improve the production of erythritol in Y. lipolytica, suggesting a great capacity and promising potential of this non-conventional yeast in converting glycerol into erythritol.
Assuntos
Eritritol/biossíntese , Proteínas Fúngicas/genética , Engenharia Metabólica/métodos , Yarrowia/crescimento & desenvolvimento , AMP Desaminase/genética , Aldose-Cetose Isomerases/genética , Técnicas de Cultura Celular por Lotes , Glicerol/metabolismo , Transaldolase/genética , Transcetolase/genética , Yarrowia/genética , Yarrowia/metabolismoRESUMO
Plants are exposed to various environmental cues that lead to reactive oxygen species (ROS) accumulation. ROS production and detoxification are tightly regulated to maintain balance. Although studies of glucose (Glc) are always accompanied by ROS in animals, the role of Glc in respect of ROS in plants is unclear. We isolated gsm2 (Glc-hypersensitive mutant 2), a mutant with a notably chlorotic-cotyledon phenotype. The chloroplast-localized GSM2 was characterized as a transaldolase in the pentose phosphate pathway. With 3% Glc treatment, fewer or no thylakoids were observed in gsm2 cotyledon chloroplasts than in wild-type cotyledon chloroplasts, suggesting that GSM2 is required for chloroplast protection under stress. gsm2 also showed evaluated accumulation of ROS with 3% Glc treatment and was more sensitive to exogenous H2O2 than the wild type. Gene expression analysis of the antioxidant enzymes in gsm2 revealed that chloroplast damage to gsm2 cotyledons results from the accumulation of excessive ROS in response to Glc. Moreover, the addition of diphenyleneiodonium chloride or phenylalanine can rescue Glc-induced chlorosis in gsm2 cotyledons. This work suggests that GSM2 functions to maintain ROS balance in response to Glc during early seedling growth and sheds light on the relationship between Glc, the pentose phosphate pathway and ROS.
Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Homeostase , RNA Helicases/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Transaldolase/metabolismo , Ácido Abscísico/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Clorofila/metabolismo , Cloroplastos/genética , Cloroplastos/metabolismo , Cotilédone/metabolismo , Regulação da Expressão Gênica de Plantas , Germinação , Glucuronidase/metabolismo , Peróxido de Hidrogênio/metabolismo , Via de Pentose Fosfato/genética , Via de Pentose Fosfato/fisiologia , Fenótipo , RNA Helicases/genética , RNA de Plantas/genética , RNA de Plantas/isolamento & purificação , Plântula/genética , Plântula/metabolismo , Transaldolase/genéticaRESUMO
Inborn errors of metabolism (IEM) involving the non-oxidative pentose phosphate pathway (PPP) include the two relatively rare conditions, transketolase deficiency and transaldolase deficiency, both of which can be difficult to diagnosis given their non-specific clinical presentations. Current biochemical testing approaches require an index of suspicion to consider targeted urine polyol testing. To determine whether a broad-spectrum biochemical test could accurately identify a specific metabolic pattern defining IEMs of the non-oxidative PPP, we employed the use of clinical metabolomic profiling as an unbiased novel approach to diagnosis. Subjects with molecularly confirmed IEMs of the PPP were included in this study. Targeted quantitative analysis of polyols in urine and plasma samples was accomplished with chromatography and mass spectrometry. Semi-quantitative unbiased metabolomic analysis of urine and plasma samples was achieved by assessing small molecules via liquid chromatography and high-resolution mass spectrometry. Results from untargeted and targeted analyses were then compared and analyzed for diagnostic acuity. Two siblings with transketolase (TKT) deficiency and three unrelated individuals with transaldolase (TALDO) deficiency were identified for inclusion in the study. For both IEMs, targeted polyol testing and untargeted metabolomic testing on urine and/or plasma samples identified typical perturbations of the respective disorder. Additionally, untargeted metabolomic testing revealed elevations in other PPP metabolites not typically measured with targeted polyol testing, including ribonate, ribose, and erythronate for TKT deficiency and ribonate, erythronate, and sedoheptulose 7-phosphate in TALDO deficiency. Non-PPP alternations were also noted involving tryptophan, purine, and pyrimidine metabolism for both TKT and TALDO deficient patients. Targeted polyol testing and untargeted metabolomic testing methods were both able to identify specific biochemical patterns indicative of TKT and TALDO deficiency in both plasma and urine samples. In addition, untargeted metabolomics was able to identify novel biomarkers, thereby expanding the current knowledge of both conditions and providing further insight into potential underlying pathophysiological mechanisms. Furthermore, untargeted metabolomic testing offers the advantage of having a single effective biochemical screening test for identification of rare IEMs, like TKT and TALDO deficiencies, that may otherwise go undiagnosed due to their generally non-specific clinical presentations.
Assuntos
Erros Inatos do Metabolismo dos Carboidratos/genética , Erros Inatos do Metabolismo/genética , Transaldolase/deficiência , Transaldolase/genética , Transcetolase/genética , Adulto , Biomarcadores/sangue , Erros Inatos do Metabolismo dos Carboidratos/sangue , Erros Inatos do Metabolismo dos Carboidratos/metabolismo , Erros Inatos do Metabolismo dos Carboidratos/patologia , Criança , Pré-Escolar , Cromatografia Líquida , Feminino , Humanos , Lactente , Masculino , Espectrometria de Massas , Erros Inatos do Metabolismo/sangue , Erros Inatos do Metabolismo/metabolismo , Erros Inatos do Metabolismo/patologia , Metabolômica , Via de Pentose Fosfato/genética , Transaldolase/sangue , Transaldolase/metabolismo , Transcetolase/sangue , Transcetolase/deficiência , Adulto JovemRESUMO
BACKGROUND: The Gram-positive facultative methylotrophic bacterium Bacillus methanolicus uses the sedoheptulose-1,7-bisphosphatase (SBPase) variant of the ribulose monophosphate (RuMP) cycle for growth on the C1 carbon source methanol. Previous genome sequencing of the physiologically different B. methanolicus wild-type strains MGA3 and PB1 has unraveled all putative RuMP cycle genes and later, several of the RuMP cycle enzymes of MGA3 have been biochemically characterized. In this study, the focus was on the characterization of the transaldolase (Ta) and its possible role in the RuMP cycle in B. methanolicus. RESULTS: The Ta genes of B. methanolicus MGA3 and PB1 were recombinantly expressed in Escherichia coli, and the gene products were purified and characterized. The PB1 Ta protein was found to be active as a homodimer with a molecular weight of 54 kDa and displayed KM of 0.74 mM and Vmax of 16.3 U/mg using Fructose-6 phosphate as the substrate. In contrast, the MGA3 Ta gene, which encodes a truncated Ta protein lacking 80 amino acids at the N-terminus, showed no Ta activity. Seven different mutant genes expressing various full-length MGA3 Ta proteins were constructed and all gene products displayed Ta activities. Moreover, MGA3 cells displayed Ta activities similar as PB1 cells in crude extracts. CONCLUSIONS: While it is well established that B. methanolicus can use the SBPase variant of the RuMP cycle this study indicates that B. methanolicus possesses Ta activity and may also operate the Ta variant of the RuMP.
Assuntos
Bacillus/enzimologia , Mutação , Transaldolase/química , Transaldolase/metabolismo , Bacillus/genética , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Escherichia coli/genética , Escherichia coli/crescimento & desenvolvimento , Peso Molecular , Pentoses/metabolismo , Fosfatos/metabolismo , Multimerização Proteica , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Transaldolase/genéticaRESUMO
BACKGROUND: During the pentose phosphate pathway (PPP), two important components, NADPH and pentoses, are provided to the cell. Previously it was shown that this metabolic pathway is a source of reducing agent for lipid synthesis from glucose in the yeast Yarrowia lipolytica. Y. lipolytica is an attractive microbial host since it is able to convert untypical feedstocks, such as glycerol, into oils, which subsequently can be transesterified to biodiesel. However, the lipogenesis process is a complex phenomenon, and it still remains unknown which genes from the PPP are involved in lipid synthesis. RESULTS: To address this problem we overexpressed five genes from this metabolic pathway: transaldolase (TAL1, YALI0F15587g), transketolase (TKL1, YALI0E06479g), ribulose-phosphate 3-epimerase (RPE1, YALI0C11880g) and two dehydrogenases, NADP+-dependent glucose-6-phosphate dehydrogenase (ZWF1, YALI0E22649g) and NADP+-dependent 6-phosphogluconate dehydrogenase (GND1, YALI0B15598g), simultaneously with diacylglycerol acyltransferase (DGA1, YALI0E32769g) and verified each resulting strain's ability to synthesize fatty acid growing on both glycerol and glucose as a carbon source. Our results showed that co-expression of DGA1 and TKL1 results in higher SCO synthesis, increasing lipid content by 40% over the control strain (DGA1 overexpression). CONCLUSIONS: Simultaneous overexpression of DGA1 and TKL1 genes results in a higher lipid titer independently from the fermentation conditions, such as carbon source, pH and YE supplementation.
Assuntos
Lipídeos/biossíntese , Transcetolase/metabolismo , Yarrowia/enzimologia , Biocombustíveis/microbiologia , Carboidratos Epimerases/genética , Carboidratos Epimerases/metabolismo , Diacilglicerol O-Aciltransferase/genética , Diacilglicerol O-Aciltransferase/metabolismo , Fermentação , Glucose/metabolismo , Glucosefosfato Desidrogenase/genética , Glucosefosfato Desidrogenase/metabolismo , Via de Pentose Fosfato , Transaldolase/genética , Transaldolase/metabolismo , Transcetolase/genética , Yarrowia/genéticaRESUMO
ß-Hydroxy-α-amino acids (ßH-AAs) are key components of many bioactive molecules as well as exist as specialised metabolites. Among these ßH-AAs, 4-fluorothreonine (4-FT) is the only naturally occurring fluorinated AA discovered thus far. Here we report overexpression and biochemical characterisation of 4-fluorothreonine transaldolase from Streptomyces sp. MA37 (FTaseMA), a homologue of FTase previously identified in the biosynthesis of 4-FT in S. cattleya. FTaseMA displays considerable substrate plasticity to generate 4-FT as well as other ß-hydroxy-α-amino acids with various functionalities at C4 position, giving the prospect of new chemo-enzymatic applications. The enzyme has a hybrid of two catalytic domains, serine hydroxymethyltransferase (S) and aldolase (A). Site-directed mutagenesis allowed the identification of the key residues of FTases, suggesting that the active site of A domain has a historical reminiscent feature in metal-dependent aldolases. Elemental analysis demonstrated that FTaseMA is indeed a Zn2+-dependent enzyme, the first example of pyridoxal phosphate (PLP) enzyme family fused with a metal-binding domain carrying out a distinct catalytic role. Finally, FTaseMA showed divergent evolutionary origin with other PLP dependent enzymes.
Assuntos
Aminoácidos Aromáticos/metabolismo , Streptomyces/enzimologia , Streptomyces/genética , Treonina/análogos & derivados , Transaldolase/metabolismo , Zinco/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Catálise , Domínio Catalítico , Cristalografia por Raios X , Cinética , Mutagênese Sítio-Dirigida , Treonina/metabolismo , Transaldolase/genéticaRESUMO
Mitochondrial dysfunction can increase oxidative stress and extend lifespan in Caenorhabditis elegans. Homeostatic mechanisms exist to cope with disruptions to mitochondrial function that promote cellular health and organismal longevity. Previously, we determined that decreased expression of the cytosolic pentose phosphate pathway (PPP) enzyme transaldolase activates the mitochondrial unfolded protein response (UPRmt) and extends lifespan. Here we report that transaldolase (tald-1) deficiency impairs mitochondrial function in vivo, as evidenced by altered mitochondrial morphology, decreased respiration, and increased cellular H2O2 levels. Lifespan extension from knockdown of tald-1 is associated with an oxidative stress response involving p38 and c-Jun N-terminal kinase (JNK) MAPKs and a starvation-like response regulated by the transcription factor EB (TFEB) homolog HLH-30. The latter response promotes autophagy and increases expression of the flavin-containing monooxygenase 2 (fmo-2). We conclude that cytosolic redox established through the PPP is a key regulator of mitochondrial function and defines a new mechanism for mitochondrial regulation of longevity.
Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Proteínas de Caenorhabditis elegans/genética , Caenorhabditis elegans/genética , Longevidade/genética , Oxigenases/genética , Transaldolase/genética , Envelhecimento/genética , Envelhecimento/patologia , Animais , Autofagia/genética , Caenorhabditis elegans/crescimento & desenvolvimento , Regulação da Expressão Gênica no Desenvolvimento , Técnicas de Silenciamento de Genes , Peróxido de Hidrogênio/farmacologia , Proteínas Quinases JNK Ativadas por Mitógeno/biossíntese , Proteínas Quinases JNK Ativadas por Mitógeno/genética , Mitocôndrias/genética , Mitocôndrias/patologia , Estresse Oxidativo/efeitos dos fármacos , Oxigenases/biossíntese , Inanição , Transaldolase/antagonistas & inibidores , Resposta a Proteínas não Dobradas/genética , Proteínas Quinases p38 Ativadas por Mitógeno/biossíntese , Proteínas Quinases p38 Ativadas por Mitógeno/genéticaRESUMO
BACKGROUND: Transaldolase deficiency (TALDO-D) is a rare autosomal recessive inborn error of the pentose phosphate pathway. Since its first description in 2001, several case reports have been published, but there has been no comprehensive overview of phenotype, genotype, and phenotype-genotype correlation. METHODS: We performed a retrospective questionnaire and literature study of clinical, biochemical, and molecular data of 34 patients from 25 families with proven TALDO-D. In some patients, endocrine abnormalities have been found. To further evaluate these abnormalities, we performed biochemical investigations on blood of 14 patients. RESULTS AND CONCLUSIONS: Most patients (n = 22) had an early-onset presentation (prenatally or before 1 month of age); 12 patients had a late-onset presentation (3 months to 9 years). Main presenting symptoms were intrauterine growth restriction, dysmorphic facial features, congenital heart disease, anemia, thrombocytopenia, and hepato(spleno)megaly. An older sib of two affected patients was asymptomatic until the age of 9 years, and only after molecular diagnosis was hepatomegaly noted. In some patients, there was gonadal dysfunction with low levels of testosterone and secondary luteinizing hormone (LH) and follicle-stimulating hormone (FSH) abnormalities later in life. This overview provides information that can be helpful for managing patients and counseling families regarding prognosis. Diagnostic guidelines, possible genotype-phenotype correlations, treatment options, and pathophysiological disease mechanisms are proposed.
Assuntos
Erros Inatos do Metabolismo dos Carboidratos/genética , Erros Inatos do Metabolismo dos Carboidratos/metabolismo , Células Endócrinas/metabolismo , Hormônios/metabolismo , Transaldolase/deficiência , Criança , Pré-Escolar , Feminino , Estudos de Associação Genética/métodos , Genótipo , Humanos , Lactente , Recém-Nascido , Masculino , Fenótipo , Estudos Retrospectivos , Inquéritos e Questionários , Transaldolase/genética , Transaldolase/metabolismoRESUMO
In the present study, we investigated the potential of Bifidobacterium spp., isolated from ruminal fluid samples from buffaloes (Bubalus bubalis) for conjugated linoleic acid (CLA) production. A total of 294 isolates were obtained from 86 ruminal fluid samples using Bifidus Selective Medium (BSM) medium, and based on phospoketolase assay, 24 isolates were presumptively confirmed to be Bifidobacterium species. Further, the isolates were confirmed morphologically, biochemically and by PCR assays for genus specific (16s rDNA) and transaldolase genes. All 24 strains were positive for conversion of linoleic acid (LA) to CLA by spectrophotometric screening. Gas chromatographic analysis showed that the strains produced cis9, trans11 and tran10, cis12 CLA isomers in LA-supplemented deMan-Rogosa-Sharpe (MRS) broth. The strains were identified as B. thermophilum (nâ¯=â¯21) and B. pseudolongum (nâ¯=â¯3) based on 16 rDNA sequence analysis. The study shows that Bifidobacterium spp., present in the rumens of buffaloes produce CLA from LA and the strains may have the potential to be used as probiotics to enhance the nutraceutical value of ruminant food products.
Assuntos
Bifidobacterium/isolamento & purificação , Bifidobacterium/metabolismo , Búfalos , Ácidos Linoleicos Conjugados/metabolismo , Rúmen/microbiologia , Animais , Técnicas Bacteriológicas , Bifidobacterium/classificação , Bifidobacterium/genética , Líquidos Corporais/microbiologia , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Filogenia , Reação em Cadeia da Polimerase , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Transaldolase/genéticaRESUMO
A large number of DNAs in eukaryote genomes can code for atypical transcripts, and their functions are controversial. It has been reported that the transcripts contain many small open reading frames (sORFs), which were originally considered as non-translatable RNAs. However, increasing evidence has suggested that some of these sORFs can encode for small peptides and some are conserved across large evolutionary distances. It has been reported that the small peptides have functions and may be involved in varieties of cellular processes, playing important roles in development, physiology, and metabolism. Among the sORFs, studies of the non-canonical gene polished rice/tarsal-less (pri/tal) in Drosophila and mille-pattes(mlpt) in Tribolium have been more thoroughly studied. The genes similar to pri/tal in other species have been defined as the tarsal-less-related gene family, tal-like gene. In this review, we described recent progress in the discovery and functional characterization of the small peptides encoded by the tal-like gene and their possible functional potentials.
Assuntos
Proteínas de Drosophila/genética , Fases de Leitura Aberta/genética , Fases de Leitura Aberta/fisiologia , Peptídeos/fisiologia , Transaldolase/genética , AnimaisRESUMO
The polycistronic and non-canonical gene tarsal-less (tal, known as pri) was reported to be required for embryonic and imaginal development in Drosophila; however, there are few reports of the tal gene in the silkworm Bombyx mori. Here, we cloned a tal-like (Bmtal) gene, and a sequence analysis showed that the Bmtal cDNA (1661 bp) contains five small open reading frames (smORFs) (A1, A2, A3, A4, and B) that encode short peptides of 11-12 (A1-A4) amino acid residues containing an LDPTG(E)L(Q)(V)Y motif that is conserved in Drosophila Tal, as well as a 32-amino-acid B peptide. Reverse transcription-quantitative polymerase chain reaction showed that the expression of the Bmtal gene was highest in the trachea, followed by the silk gland and Malpighian tubule, in day 3 fifth-instar larvae. Subcellular localization showed that BmTal localized in the nucleus. By regulating the expression of the full-length Bmtal gene and the functional smORFs of Bmtal, we showed that the expression levels of the Bmovo gene and genes related to the Notch, transforming growth factor-ß, and Hippo signaling pathways changed with changes in BmTal peptide expression. A co-immunoprecipitation assay showed that BmTal interacts with polyubiquitin, which triggered degradation and/or processing of the 14-3-3 protein zeta. A comparative transcriptome analysis showed that 2843 (2045) genes were up- (down)-regulated after Bmtal gene expression was up-regulated. The up- (down)-regulated differentially expressed genes were enriched in 326 (278) gene ontology terms (P ≤ 0.05) and 54 (59) Kyoto Encyclopedia of Genes and Genomes pathways (P ≤ 0.05), and the results indicated that the BmTal peptides could function as mediators of hormone levels or the activities of multiple pathways, including the peroxisome proliferator-activated receptor, Hedgehog, mitogen-activated protein kinase, adipocytokine, and gonadotropin-releasing hormone signaling pathways, as well as the innate immune response. These results increase our understanding of the function and mechanism of BmTal at the genome-wide level.
Assuntos
Bombyx/enzimologia , Bombyx/genética , Transaldolase/genética , Transaldolase/metabolismo , Estruturas Animais/enzimologia , Animais , Núcleo Celular/enzimologia , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Redes Reguladoras de Genes , Imunoprecipitação , Mapeamento de Interação de Proteínas , Mapas de Interação de Proteínas , Reação em Cadeia da Polimerase em Tempo Real , Transdução de SinaisRESUMO
Ultraviolet-absorbing chemicals are useful in cosmetics and skin care to prevent UV-induced skin damage. We demonstrate here that heterologous production of shinorine, which shows broad absorption maxima in the UV-A and UV-B region. A shinorine producing Corynebacterium glutamicum strain was constructed by expressing four genes from Actinosynnema mirum DSM 43827, which are responsible for the biosynthesis of shinorine from sedoheptulose-7-phosphate in the pentose phosphate pathway. Deletion of transaldolase encoding gene improved shinorine production by 5.2-fold. Among the other genes in pentose phosphate pathway, overexpression of 6-phosphogluconate dehydrogenase encoding gene further increased shinorine production by 60% (19.1 mg/L). The genetic engineering of the pentose phosphate pathway in C. glutamicum improved shinorine production by 8.3-fold in total, and could be applied to produce the other chemicals derived from sedoheptulose-7-phosphate.
Assuntos
Corynebacterium glutamicum/metabolismo , Cicloexilaminas/síntese química , Glicina/análogos & derivados , Engenharia Metabólica , Protetores Solares/síntese química , Actinobacteria/genética , Corynebacterium glutamicum/genética , Genes Bacterianos , Glicina/síntese química , Espectrometria de Massas , Via de Pentose Fosfato , Fosfogluconato Desidrogenase/metabolismo , Recombinação Genética , Fosfatos Açúcares/química , Transaldolase/genética , Raios UltravioletaRESUMO
Transaldolase deficiency is a rare inborn autosomal recessive error of the pentose phosphate pathway that, to date, has been diagnosed in 33 patients, including 4 from Poland. The aim of this manuscript was to present the clinical presentation, pathogenesis and diagnostic process of transaldolase deficiency. The authors also present a diagnostic algorithm of transaldolase deficiency.
Assuntos
Erros Inatos do Metabolismo dos Carboidratos/diagnóstico , Erros Inatos do Metabolismo dos Carboidratos/patologia , Mutação , Transaldolase/deficiência , Adolescente , Adulto , Erros Inatos do Metabolismo dos Carboidratos/genética , Criança , Pré-Escolar , Humanos , Lactente , Recém-Nascido , Guias de Prática Clínica como Assunto , Álcoois Açúcares/urina , Transaldolase/genéticaRESUMO
The human genitourinary tract is a common anatomical niche for polymicrobial infection and a leading site for the development of bacteremia and sepsis. Most uncomplicated, community-acquired urinary tract infections (UTI) are caused by Escherichia coli, while another bacterium, Proteus mirabilis, is more often associated with complicated UTI. Here, we report that uropathogenic E. coli and P. mirabilis have divergent requirements for specific central pathways in vivo despite colonizing and occupying the same host environment. Using mutants of specific central metabolism enzymes, we determined glycolysis mutants lacking pgi, tpiA, pfkA, or pykA all have fitness defects in vivo for P. mirabilis but do not affect colonization of E. coli during UTI. Similarly, the oxidative pentose phosphate pathway is required only for P. mirabilis in vivo. In contrast, gluconeogenesis is required only for E. coli fitness in vivo. The remarkable difference in central pathway utilization between E. coli and P. mirabilis during experimental UTI was also observed for TCA cycle mutants in sdhB, fumC, and frdA. The distinct in vivo requirements between these pathogens suggest E. coli and P. mirabilis are not direct competitors within host urinary tract nutritional niche. In support of this, we found that co-infection with E. coli and P. mirabilis wild-type strains enhanced bacterial colonization and persistence of both pathogens during UTI. Our results reveal that complementary utilization of central carbon metabolism facilitates polymicrobial disease and suggests microbial activity in vivo alters the host urinary tract nutritional niche.
Assuntos
Coinfecção/metabolismo , Glicólise/fisiologia , Fenômenos Fisiológicos da Nutrição , Infecções Urinárias/metabolismo , Animais , Coinfecção/genética , Coinfecção/microbiologia , Escherichia coli/enzimologia , Escherichia coli/genética , Escherichia coli/patogenicidade , Infecções por Escherichia coli/complicações , Infecções por Escherichia coli/metabolismo , Infecções por Escherichia coli/microbiologia , Feminino , Glicólise/genética , Humanos , Camundongos , Camundongos Endogâmicos CBA , Infecções por Proteus/complicações , Infecções por Proteus/metabolismo , Infecções por Proteus/microbiologia , Proteus mirabilis/enzimologia , Proteus mirabilis/genética , Proteus mirabilis/patogenicidade , Transaldolase/genética , Infecções Urinárias/microbiologiaRESUMO
The pentose phosphate pathway (PPP) plays an important role in the efficiency of xylose fermentation during cellulosic ethanol production. In simultaneous saccharification and co-fermentation (SSCF), the optimal temperature for cellulase hydrolysis of lignocellulose is much higher than that of fermentation. Successful use of SSCF requires optimization of the expression of PPP genes at elevated temperatures. This study examined the combinatorial expression of PPP genes at high temperature. The results revealed that over-expression of TAL1 and TKL1 in Saccharomyces cerevisiae (S. cerevisiae) at 30 °C and over-expression of all PPP genes at 36 °C resulted in the highest ethanol productivities. Furthermore, combinatorial over-expression of PPP genes derived from S. cerevisiae and a thermostable yeast Kluyveromyces marxianus allowed the strain to ferment xylose with ethanol productivity of 0.51 g/L/h, even at 38 °C. These results clearly demonstrate that xylose metabolism can be improved by the utilization of appropriate combinations of thermostable PPP genes in high-temperature production of ethanol.
Assuntos
Etanol/metabolismo , Via de Pentose Fosfato/genética , Saccharomyces cerevisiae/genética , Xilose/metabolismo , Celulase/metabolismo , Fermentação , Temperatura Alta , Kluyveromyces/genética , Lignina/metabolismo , Saccharomyces cerevisiae/metabolismo , Transaldolase/genética , Transcetolase/genéticaRESUMO
Clonostachys rosea is a promising biocontrol agent that parasitizes various fungal plant pathogens. In this paper, transaldolase gene Tal67 was found to be greatly upregulated in C. rosea isolate 67-1 during mycoparasitism of Sclerotinia sclerotiorum sclerotia. Quantitative real-time PCR revealed a significant increase in expression at 0-48 h after induction by sclerotia, and the level peaked at 13.9-fold higher than the control at 24 h. Gene disruption led to a decrease in the growth rate of the Tal67-deficient strain ΔTal67 to 5.3 mm/day, which was much lower than the wild type and the complemented strain ΔTal67+ (P < 0.05). The antagonistic activity of ΔTal67 against Botrytis cinerea was 15.8% lower than the wild type, and the parasitic rate to S. sclerotiorum decreased by 24.6%. However, reinsertion of the transaldolase gene recovered the fungicidal activity of C. rosea. The efficacy of the mutants against soybean Sclerotinia stem rot was evaluated in the greenhouse, and the control efficiency of isolate 67-1 reached 65.3%, while the efficiency of the ΔTal67 strain decreased sharply to 17.8%, and the complemented strain ΔTal67+ recovered to 64.8%. These results suggest that Tal67 plays an important role in the growth and biocontrol activity of C. rosea.