RESUMEN
S-RNase plays vital roles in the process of self-incompatibility (SI) in Rutaceae plants. Data have shown that the rejection phenomenon during self-pollination is due to the degradation of pollen tube RNA by S-RNase. The cytoskeleton microfilaments of pollen tubes are destroyed, and other components cannot extend downwards from the stigma and, ultimately, cannot reach the ovary to complete fertilisation. In this study, four S-RNase gene sequences were identified from the 'XiangShui' lemon genome and ubiquitome. Sequence analysis revealed that the conserved RNase T2 domains within S-RNases in 'XiangShui' lemon are the same as those within other species. Expression pattern analysis revealed that S3-RNase and S4-RNase are specifically expressed in the pistils, and spatiotemporal expression analysis showed that the S3-RNase expression levels in the stigmas, styles and ovaries were significantly higher after self-pollination than after cross-pollination. Subcellular localisation analysis showed that the S1-RNase, S2-RNase, S3-RNase and S4-RNase were found to be expressed in the nucleus according to laser confocal microscopy. In addition, yeast two-hybrid (Y2H) assays showed that S3-RNase interacted with F-box, Bifunctional fucokinase/fucose pyrophosphorylase (FKGP), aspartic proteinase A1, RRP46, pectinesterase/pectinesterase inhibitor 51 (PME51), phospholipid:diacylglycerol acyltransferase 1 (PDAT1), gibberellin receptor GID1B, GDT1-like protein 4, putative invertase inhibitor, tRNA ligase, PAP15, PAE8, TIM14-2, PGIP1 and p24beta2. Moreover, S3-RNase interacted with TOPP4. Therefore, S3-RNase may play an important role in the SI of 'XiangShui' lemon.
Asunto(s)
Proteasas de Ácido Aspártico , Citrus , Autoincompatibilidad en las Plantas con Flores , Citrus/metabolismo , Diacilglicerol O-Acetiltransferasa , Endorribonucleasas , Fucosa , Giberelinas , Fosfolípidos , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Polen/genética , ARN , ARN Ligasa (ATP) , Ribonucleasas/genética , Ribonucleasas/metabolismo , Autoincompatibilidad en las Plantas con Flores/genética , beta-FructofuranosidasaRESUMEN
New antibiotics are urgently required in clinical treatment and agriculture with the development of antimicrobial resistance. However, products discovered by repeating previous strategies are either not antibiotics or already known antibiotics. There is a growing demand for efficient strategies to discover new antibiotics. With the continuous improvement of gene sequencing technology and genomic data, some mining strategies have emerged. These strategies are expected to alleviate the current dilemma of antibiotics. In this review, we discuss the recent advances in discovery of bacterial antibiotics from the following aspects: activation of silent gene clusters, genome mining and metagenome mining. In the future, we envision the discovery of natural antibiotic will be accelerated by the combination of these strategies.
Asunto(s)
Antibacterianos , Productos Biológicos , Antibacterianos/farmacología , Bacterias/genética , Genómica , Metagenoma , Familia de MultigenesRESUMEN
Three coordination polymers, [Cd(L)2(H2O)2]n (1), [Zn(L)2(H2O)2]n (2) and [Mn(L)2]n (3) were prepared by reacting 5-(3-pyridyl)-1,3,4-oxadiazole-2-thioacetic acid (HL) with corresponding metal acetate in DMF/CH3CN medium under solvothermal condition. The isolated complexes were characterized by elemental analysis and infrared spectroscopy. The X-ray crystallographic analysis revealed double strand structure of 1 and 2, and 3D framework of 3. The different structures of these complexes indicate that the configuration of the ligand and the reaction condition play a key role in self-assemble of complexes 1-3. Furthermore, photoluminescent properties of 1 and 2 were also studied in the solid state.
RESUMEN
With the emergence of various filtering technologies, the radar jamming efficiency of the technology based on radar cross section is ever lower, therefore cannot meet military requirements. In this context, the jamming technology based on attenuation mechanism has been developed and plays an increasingly important role in disturbing radar detecting. Magnetically expanded graphite (MEG) has excellent attenuation efficiency because it can cause dielectric loss as well as magnetic loss. Moreover, MEG features good impedance matching, which makes more incidence of electromagnetic waves into the material; and its multi-layer structure is conducive for electromagnetic wave reflection and absorption. In this work, the structure model of MEG was established by analyzing the layered structure of expanded graphite (EG) and the dispersion of intercalated magnetic particles. The electromagnetic parameters of thus-modeled MEG were calculated based on the equivalent medium theory; and effects of EG size, magnetic particle type and volume fraction on the attenuation performance were studied by the variational method. It is indicated that MEG with 500-µm diameter has the best attenuation effect and the highest increment of absorption cross section appears at 50% volume fraction of the magnetic particles at 2 GHz. The imaginary part of complex permeability of the magnetic material has the most significant influence on the attenuation effect of MEG. This study provides guidance for the design and application of MEG materials in disturbing radar detecting field.
RESUMEN
APETALA1 (AP1), CAULIFLOWER (CAL) and FRUITFULL (FUL) were homologous genes with redundant functions in the process of flower transformation and floral development in Arabidopsis. Two CALs genes, MiCAL1 and MiCAL2, were cloned from mango (Mangifera indica L.). Their full-length sequences contained 717 bp and 714 bp, encoding 239 and 238 amino acids, respectively. Both the MiCAL1 and MiCAL2 proteins contained typical MADS-box and K-box domains and therefore belonged to the CAL-like protein family. MiCAL1 and MiCAL2 were expressed in all tissues at the inflorescence elongation stage and flowering stage, with the highest expression in the leaves at the flowering stage. They had similar expression patterns during flower development, with the highest expression levels in leaves during flower differentiation and the lowest expression levels during fruit development. Overexpression of MiCAL1 and MiCAL2 resulted in significantly earlier flowering in Arabidopsis. Overexpression of MiCAL1 resulted in terminal flowers with normal flower organs, while overexpression of MiCAL2 induced partially variation in floral organs but had no effect on inflorescences. Yeast two-hybrid (Y2H) experiments showed that MiCAL1 and MiCAL2 can interact with several flower-related proteins as well as stress response proteins, such as SEP1, SVP1, SVP2, SOC1G and Di19-4. These results suggest that these two MiCALs genes may have an important influence on mango flowering.
Asunto(s)
Arabidopsis , Brassica , Mangifera , Arabidopsis/metabolismo , Mangifera/genética , Mangifera/metabolismo , Regulación de la Expresión Génica de las Plantas , Expresión Génica Ectópica , Brassica/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Flores , Plantas Modificadas Genéticamente/genética , Plantas Modificadas Genéticamente/metabolismo , Proteínas de Dominio MADS/genéticaRESUMEN
Genetic engineering is a powerful method to improve the fermentation yield of bacterial metabolites. Since many biosynthetic mechanisms of bacterial metabolites have been unveiled, genetic engineering approaches have been applied to various issues of biosynthetic pathways, such as transcription, translation, post-translational modification, enzymes, transporters, etc. In this article, natamycin, avermectins, gentamicins, piperidamycins, and ß-valienamine have been chosen as examples to review recent progress in improving their production by genetic engineering approaches. In these cases, not only yields of target products have been increased, but also yields of by-products have been decreased, and new products have been created.
Asunto(s)
Acremonium/genética , Proteínas Bacterianas/genética , Regulación Bacteriana de la Expresión Génica , Ingeniería Genética/métodos , Micromonospora/genética , Streptomyces/genética , Acremonium/enzimología , Proteínas Bacterianas/metabolismo , Vías Biosintéticas/genética , Ciclohexenos , Fermentación , Gentamicinas/biosíntesis , Hexosaminas/biosíntesis , Ivermectina/análogos & derivados , Ivermectina/metabolismo , Micromonospora/enzimología , Natamicina/biosíntesis , Biosíntesis de Proteínas , Streptomyces/enzimología , Transcripción GenéticaRESUMEN
While it is known that spermatogonial stem cells (SSCs) initiate the production of male germ cells, the mechanisms of SSC self-renewal, proliferation, and differentiation remain poorly understood. We have previously identified Strawberry Notch 1 (SBNO1), a vertebrate strawberry notch family protein, in the proteome profile for mouse SSC maturation and differentiation, revealing SBNO1 is associated with neonatal testicular development. To explore further the location and function of SBNO1 in the testes, we performed Sbno1 gene knockdown in mice to study the effects of SBNO1 on neonatal testicular and SSC development. Our results revealed that SBNO1 is required for neonatal testicular and SSC development in mice. Particularly, in vitro Sbno1 gene knockdown with morpholino oligonucleotides caused a reduction of SSCs and inactivation of the noncanonical Wnt pathway, through Jun N-terminal kinases. Our study suggests SBNO1 maintains SSCs by promoting the noncanonical Wnt pathway.
Asunto(s)
Células Madre Germinales Adultas/metabolismo , Proliferación Celular/fisiología , Proteínas Represoras/metabolismo , Testículo/metabolismo , Vía de Señalización Wnt/fisiología , Células Madre Germinales Adultas/citología , Animales , Técnicas de Silenciamiento del Gen , Masculino , Ratones , Proteoma , Proteínas Represoras/genética , Testículo/citologíaRESUMEN
Colorectal cancer (CRC) is one of the major types of cancer and causes of mortality worldwide, and it remains the third most common cause of cancerassociated mortality worldwide. MicroRNAs (miRNAs) are a class of small RNAs, which have been shown to be associated with CRC. In the present study, an MTT assay and proliferating cell nuclear antigen (PCNA) protein examination assay were performed to detect RKO cell viability. Hoechst staining, and caspase3 activity and BrdU incorporation assays were performed to detect RKO cell apoptosis, respectively. Reverse transcriptionquantitative polymerase chain reaction (RTqPCR) and western blot analyses were used to analyze the expression of cyclooxygenase2 (COX2). Western blot analysis was also used to analyze the expression of vascular endothelial growth factor (VEGF) and mitogenactivated protein kinase (MAPK) signal molecules, including extracellular signalregulated kinase (ERK), p38 and cJun Nterminal kinase (JNK). The target genes of miR-125 were predicted using a double luciferase reporter gene assay. The results of the MTT assay showed that RKO cell viability was decreased by an miRNA-125 mimic and increased by the miRNA-125 inhibitor. The RKO cell viability was significantly correlated with the expression of PCNA. The migration of RKO cells was significantly downregulated in the miR-125 mimicstransfected cells and upregulated in the miRNA-125 inhibitortransfected cells. The results of Hoechst staining and the caspase3 activity and BrdU incorporation assays showed that RKO cell apoptosis was increased following miRNA-125 mimic transfection and decreased following miRNA-125 inhibitor transfection. The results of the RTqPCR and western blot analysis showed that the expression of COX2 was increased in the miR-125 mimictransfected cells and decreased in the miR-125 inhibitortransfected cells. Using an online miRNA target prediction database, the double luciferase reporter gene assay showed that miR125 targeted and inhibited the expression of VEGF through target sites located in the 3' untranslated region of VEGF mRNA. In conclusion, the abnormal expression of miR125 was found to be closely associated with CRC. Therefore, miR125 may be a novel therapeutic target for CRC.
Asunto(s)
Neoplasias Colorrectales/genética , Neoplasias Colorrectales/patología , MicroARNs/metabolismo , Factor A de Crecimiento Endotelial Vascular/metabolismo , Regiones no Traducidas 3'/genética , Apoptosis/genética , Secuencia de Bases , Muerte Celular , Línea Celular Tumoral , Movimiento Celular/genética , Proliferación Celular/genética , Ciclooxigenasa 2/metabolismo , Regulación Neoplásica de la Expresión Génica , Humanos , Luciferasas/metabolismo , Sistema de Señalización de MAP Quinasas/genética , MicroARNs/genéticaRESUMEN
Extracellular cysteine (Cys)/cystine (CySS) redox potential (E(h)) has been shown to regulate diverse biological processes, including enzyme catalysis, gene expression, and signaling pathways for cell proliferation and apoptosis, and is sensitive to aging, smoking, and other host factors. However, the effects of extracellular Cys/CySS redox on the nervous system remain unknown. In this study, we explored the role of extracellular Cys/CySS E(h) in metabotropic glutamate receptor 5 (mGlu5) activation to understand the mechanism of its regulation of nerve cell growth and activation. We showed that the oxidized Cys/CySS redox state (0 mV) in C6 glial cells induced a significant increase in mGlu5-mediated phosphorylation of extracellular signal-regulated kinase (ERK), blocked by an inhibitor of mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (MEK), U0126, a nonpermeant alkylating agent, 4-acetamide-4'-maleimidylstilbene-2,2'-disulfonic acid (AMS), and a specific mGlu5 antagonist, 2-methyl-6-(phenylethynyl)pyridine (MPEP), respectively. ERK phosphorylation under oxidized extracellular Cys/CySS E(h) was confirmed in mGlu5-overexpressed human embryonic kidney 293 (HEK293) cells. Oxidized extracellular Cys/CySS E(h) also stimulated the generation of intracellular reactive oxygen species (ROS) involved in the phosphorylation of ERK by mGlu5. Moreover, activation of mGlu5 by oxidized extracellular Cys/CySS E(h) was found to affect expression of NF-κB and inducible nitric oxide synthase (iNOS). The results also showed that extracellular Cys/CySS E(h) involved in the activation of mGlu5 controlled cell death and cell activation in neurotoxicity. In addition, plasma Cys/CySS E(h) was found to be associated with the process of Parkinson's disease (PD) in a rotenone-induced rat model of PD together with dietary deficiency and supplementation of sulfur amino acid (SAA). The effects of extracellular Cys/CySS E(h) on SAA dietary deficiency in the rotenone-induced rat model of PD was almost blocked by MPEP pretreatment, further indicating that oxidized extracellular Cys/CySS E(h) plays a role in mGlu5 activity. Taken together, the results indicate that mGlu5 can be activated by extracellular Cys/CySS redox in nerve cells, which possibly contributes to the process of PD. These in vitro and in vivo findings may aid in the development of potential new nutritional strategies that could assist in slowing the degeneration of PD.