Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 20.035
Filtrar
1.
Anticancer Res ; 39(10): 5339-5344, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31570427

RESUMO

BACKGROUND/AIM: Gemcitabine is standard first-line treatment for patients with advanced pancreatic cancer, however the efficacy is limited. Although acquired drug resistance and side-effects are known to limit efficacy, opposite effects of a drug, which enhance the malignancy of treated cancer, have been observed but are not well understood. The aim of the present study was to determine whether gemcitabine has such opposite effects on the BxPC-3 human pancreatic cancer cell line expressing green fluorescent protein (BxPC-3-GFP) in an orthotopic mouse model. MATERIALS AND METHODS: BxPC-3-GFP tumors grown subcutaneously in nude mice were harvested. Tumor fragments were orthotopically implanted in the tail of the pancreas of nude mice using the technique of surgical orthotopic implantation. The BxPC-3-GFP orthotopic models were divided randomly into three groups: Group 1: untreated control; Group 2: low-dose gemcitabine (weekly intraperitoneal injection at 25 mg/kg for 6 weeks); Group 3: high-dose gemcitabine (weekly intraperitoneal injection at 125 mg/kg for 6 weeks). Each group comprised eight mice. Tumor size, fluorescent area of metastases, and body weight were measured. RESULTS: Low- and high-dose gemcitabine inhibited primary tumor growth in a dose-dependent manner, and to the greatest extent by high-dose gemcitabine compared to the untreated control (p=0.0134). In contrast, the extent of metastasis on the peritoneum was significantly increased by low-dose gemcitabine compared to the untreated control (p=0.0112). The extent of metastasis showed no significant difference between the untreated control and mice treated with high-dose gemcitabine. Body weight of the treated mice was not significantly different from that of the untreated mice. CONCLUSION: The use of very bright GFP expressing of BxPC-3 cells and the orthotopic model demonstrated an unexpected increase in metastasis by low-dose gemcitabine. Future experiments will investigate the mechanism of this phenomenon.


Assuntos
Antimetabólitos Antineoplásicos/administração & dosagem , Desoxicitidina/análogos & derivados , Metástase Neoplásica/tratamento farmacológico , Neoplasias Pancreáticas/tratamento farmacológico , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Desoxicitidina/administração & dosagem , Modelos Animais de Doenças , Proteínas de Fluorescência Verde/metabolismo , Humanos , Camundongos , Camundongos Nus , Pâncreas/efeitos dos fármacos , Pâncreas/metabolismo , Neoplasias Pancreáticas/metabolismo
2.
Gene ; 717: 144043, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31400407

RESUMO

Genes involved in the repair of DNA damage are emerging as playing important roles during the disease processes caused by pathogenic fungi. However, there are potentially hundreds of genes involved in DNA repair in a fungus and some of those genes can play additional roles within the cell. One such gene is RAD23, required for virulence of the human pathogenic fungus Cryptococcus neoformans, that encodes a protein involved in the nucleotide excision repair (NER) pathway. However, Rad23 is a dual function protein, with a role in either repair of damaged DNA or protein turn over by directing proteins to the proteasome. Here, these two functions of Rad23 were tested by the creation of a series of domain deletion alleles of RAD23 and the assessment of the strains for DNA repair, proteasome functions, and virulence properties. Deletion of the different domains was able to uncouple the two functions of Rad23, and the phenotypes of strains carrying such forms indicated that the role of RAD23 in virulence is due to its function in proteasomal-mediated protein degradation rather than NER.


Assuntos
Cryptococcus neoformans/genética , Cryptococcus neoformans/patogenicidade , Reparo do DNA/fisiologia , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Animais , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Larva/microbiologia , Mariposas/microbiologia , Mutação , Complexo de Endopeptidases do Proteassoma/metabolismo , Domínios Proteicos , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Estresse Fisiológico/genética , Virulência
3.
Nat Commun ; 10(1): 2947, 2019 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-31270320

RESUMO

To expand the toolbox of imaging in living cells, we have engineered a single-chain variable fragment binding the linear HA epitope with high affinity and specificity in vivo. The resulting probe, called the HA frankenbody, can light up in multiple colors HA-tagged nuclear, cytoplasmic, membrane, and mitochondrial proteins in diverse cell types. The HA frankenbody also enables state-of-the-art single-molecule experiments in living cells, which we demonstrate by tracking single HA-tagged histones in U2OS cells and single mRNA translation dynamics in both U2OS cells and neurons. Together with the SunTag, we also track two mRNA species simultaneously to demonstrate comparative single-molecule studies of translation can now be done with genetically encoded tools alone. Finally, we use the HA frankenbody to precisely quantify the expression of HA-tagged proteins in developing zebrafish embryos. The versatility of the HA frankenbody makes it a powerful tool for imaging protein dynamics in vivo.


Assuntos
Epitopos/metabolismo , Sondas Moleculares/metabolismo , Proteínas Recombinantes de Fusão/metabolismo , Imagem Individual de Molécula , Animais , Linhagem Celular Tumoral , Embrião não Mamífero/metabolismo , Proteínas de Fluorescência Verde/metabolismo , Neurônios/metabolismo , Biossíntese de Proteínas , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas Recombinantes de Fusão/isolamento & purificação , Anticorpos de Cadeia Única/metabolismo , Coloração e Rotulagem , Peixe-Zebra/embriologia
4.
Nat Commun ; 10(1): 2960, 2019 07 04.
Artigo em Inglês | MEDLINE | ID: mdl-31273196

RESUMO

Clone collections of modified strains ("libraries") are a major resource for systematic studies with the yeast Saccharomyces cerevisiae. Construction of such libraries is time-consuming, costly and confined to the genetic background of a specific yeast strain. To overcome these limitations, we present CRISPR-Cas12a (Cpf1)-assisted tag library engineering (CASTLING) for multiplexed strain construction. CASTLING uses microarray-synthesized oligonucleotide pools and in vitro recombineering to program the genomic insertion of long DNA constructs via homologous recombination. One simple transformation yields pooled libraries with >90% of correctly tagged clones. Up to several hundred genes can be tagged in a single step and, on a genomic scale, approximately half of all genes are tagged with only ~10-fold oversampling. We report several parameters that affect tagging success and provide a quantitative targeted next-generation sequencing method to analyze such pooled collections. Thus, CASTLING unlocks avenues for increasing throughput in functional genomics and cell biology research.


Assuntos
Sistemas CRISPR-Cas/genética , Técnicas Genéticas , Saccharomyces cerevisiae/genética , Células Clonais , Biblioteca Gênica , Engenharia Genética , Genoma Fúngico , Proteínas de Fluorescência Verde/metabolismo , Proteínas Nucleares/metabolismo
5.
Nat Commun ; 10(1): 2906, 2019 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-31266945

RESUMO

A GGGGCC hexanucleotide repeat expansion in intron 1 of chromosome 9 open reading frame 72 (C9ORF72) gene is the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia. Repeat-associated non-ATG translation of dipeptide repeat proteins (DPRs) contributes to the neuropathological features of c9FTD/ALS. Among the five DPRs, arginine-rich poly-PR are reported to be the most toxic. Here, we generate a transgenic mouse line that expresses poly-PR (GFP-PR28) specifically in neurons. GFP-PR28 homozygous mice show decreased survival time, while the heterozygous mice show motor imbalance, decreased brain weight, loss of Purkinje cells and lower motor neurons, and inflammation in the cerebellum and spinal cord. Transcriptional analysis shows that in the cerebellum, GFP-PR28 heterozygous mice show differential expression of genes related to synaptic transmission. Our findings show that GFP-PR28 transgenic mice partly model neuropathological features of c9FTD/ALS, and show a role for poly-PR in neurodegeneration.


Assuntos
Esclerose Amiotrófica Lateral/fisiopatologia , Proteína C9orf72/genética , Dipeptídeos/genética , Modelos Animais de Doenças , Esclerose Amiotrófica Lateral/genética , Esclerose Amiotrófica Lateral/metabolismo , Animais , Proteína C9orf72/metabolismo , Dipeptídeos/metabolismo , Dipeptídeos/toxicidade , Feminino , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Atividade Motora
6.
Nat Commun ; 10(1): 2905, 2019 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-31266953

RESUMO

Delivery into mammalian cells remains a significant challenge for many applications of proteins as research tools and therapeutics. We recently reported that the fusion of cargo proteins to a supernegatively charged (-30)GFP enhances encapsulation by cationic lipids and delivery into mammalian cells. To discover polyanionic proteins with optimal delivery properties, we evaluate negatively charged natural human proteins for their ability to deliver proteins into cultured mammalian cells and human primary fibroblasts. Here we discover that ProTα, a small, widely expressed, intrinsically disordered human protein, enables up to ~10-fold more efficient cationic lipid-mediated protein delivery compared to (-30)GFP. ProTα enables efficient delivery at low- to mid-nM concentrations of two unrelated genome editing proteins, Cre recombinase and zinc-finger nucleases, under conditions in which (-30)GFP fusion or cationic lipid alone does not result in substantial activity. ProTα may enable mammalian cell protein delivery applications when delivery potency is limiting.


Assuntos
Edição de Genes/métodos , Lipossomos/química , Proteínas/química , Edição de Genes/instrumentação , Proteínas de Fluorescência Verde/química , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Células HeLa , Humanos , Integrases/química , Integrases/genética , Integrases/metabolismo , Lipossomos/metabolismo , Transporte Proteico , Proteínas/genética , Proteínas/metabolismo , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Nucleases de Dedos de Zinco/química , Nucleases de Dedos de Zinco/genética , Nucleases de Dedos de Zinco/metabolismo
7.
Int J Nanomedicine ; 14: 4353-4366, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31354265

RESUMO

Purpose: Gene therapy has become a promising remedy to treat disease by modifying the person's genes. The therapeutic potential of related tools such as CRISPR-Cas9 depends on the efficiency of delivery to the targeted cells. Numerous transfection reagents have been designed and lots of efforts have been devoted to develop carriers for this purpose. Therefore, the aim of the present study was to develop novel cholesterol-rich lipid-based nanoparticles to enhance transfection efficiency and serum stability. Materials and methods: We constructed two-, three- and four-component cationic liposomes (CLs) to evaluate the combined effect of cholesterol domain and DOPE (dioleoyl phosphatidylethanolamine), a fusogenic lipid, and the PEG (polyethylene glycol) moiety location inside or outside of the cholesterol domain on transfection efficiency and other properties of the particle. Lipoplex formation and pDNA (plasmid DNA) entrapment were assessed by gel retardation assay at different N/P ratios (3, 5, 7). Physicochemical characteristics, cytotoxicity, serum stability and endosomal escape capability of the lipoplexes were studied and transfection potential was measured by firefly luciferase assay. Next, HEK293 cell line stably expressing GFP was utilized to demonstrate the editing of a reporter through Cas9 and sgRNA plasmids delivery by the selected CL formula, which showed the highest transfection efficiency. Results: Among the designed CLs, the four-component formula [DOTAP (1,2-dioleoyl-3-trimethylammoniumpropane)/DOPE/cholesterol/Chol-PEG (cholesterol-polyethylene glycol)] showed the highest rate of transfection at N/P 3. Finally, transfection of Cas9/sgRNA by this formulation at N/P 3 resulted in 39% gene-editing efficiency to knockout GFP reporter. The results also show that this CL with no cytotoxicity effect can totally protect the plasmids from enzymatic degradation in serum. Conclusion: The novel PEGylated cholesterol domain lipoplex providing serum stability, higher transfection efficiency and endosomal release can be used for in vivo Cas9/sgRNA delivery and other future gene-therapy applications.


Assuntos
Proteína 9 Associada à CRISPR/metabolismo , Sistemas CRISPR-Cas/genética , Colesterol/química , Edição de Genes , Nanopartículas/química , Transfecção/métodos , Cátions/química , Morte Celular , Colesterol/análogos & derivados , Ensaio de Desvio de Mobilidade Eletroforética , Endossomos/metabolismo , Ácidos Graxos Monoinsaturados/química , Proteínas de Fluorescência Verde/metabolismo , Células HEK293 , Humanos , Lipossomos/química , Tamanho da Partícula , Fosfatidiletanolaminas/química , Plasmídeos/metabolismo , Polietilenoglicóis/química , Compostos de Amônio Quaternário/química , RNA Guia/metabolismo , Eletricidade Estática
8.
World J Microbiol Biotechnol ; 35(8): 119, 2019 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-31332541

RESUMO

The microalgal genus of Nannochloropsis is considered one of the most promising organisms for the production of biofuels due to their high lipid content. Transformation systems for marine Nannochloropsis species have been established in the recent decade, however, genetic manipulation of Nannochloropsis limnetica, the only known freshwater species in this genus, is not yet available. Based on established marine Nannochloropsis species electrotransformation protocol, nuclear genetic transformation was established in N. limnetica, meanwhile the appropriate antibiotic selection concentration and electric field strength of electroporation were determined. For the selection of transformants in N. limnetica on plates, 0.07 µg mL-1 of zeocin or 5 µg mL-1 of hygromycin B was proved sufficient, and the transformation efficiency was < 2 × 10-8 with a single pulse ranging from 2200 to 2600 V using 2-mm electroporation cuvettes. Pretreatment of N. limnetica with 10 mM lithium acetate and 3 mM dithiothreitol before electroporation increased transformation efficiency hundreds of times, and the highest transformation efficiency of 10-11 × 10-6 was obtained with an electric field strength of 12,000 V/cm. Our results help to expand the biotechnological applications of this freshwater species and provide means for successful electrotransformation of other microalgae as well. High-efficiency transformation of freshwater Nannochloropsis pretreatment of N. limnetica with 10 mM lithium acetate and 3 mM dithiothreitol before electroporation increased transformation efficiency hundreds of times.


Assuntos
Eletroporação , Água Doce/microbiologia , Microalgas/metabolismo , Estramenópilas/metabolismo , Acetatos , Regulação da Expressão Gênica , Genes Reporter , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Microalgas/genética , Plasmídeos/genética , Plasmídeos/metabolismo , Estramenópilas/genética , Transformação Genética
9.
Adv Mater ; 31(33): e1902575, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31215123

RESUMO

A main challenge to broaden the biomedical application of CRISPR/Cas9 (clustered regularly interspaced short palindromic repeat (CRISPR) associated protein 9) genome editing technique is the delivery of Cas9 nuclease and single-guide RNA (sgRNA) into the specific cell and organ. An effective and very fast CRISPR/Cas9 genome editing in vitro and in vivo enabled by bioreducible lipid/Cas9 messenger RNA (mRNA) nanoparticle is reported. BAMEA-O16B, a lipid nanoparticle integrated with disulfide bonds, can efficiently deliver Cas9 mRNA and sgRNA into cells while releasing RNA in response to the reductive intracellular environment for genome editing as fast as 24 h post mRNA delivery. It is demonstrated that the simultaneous delivery of Cas9 mRNA and sgRNA using BAMEA-O16B knocks out green fluorescent protein (GFP) expression of human embryonic kidney cells with efficiency up to 90%. Moreover, the intravenous injection of BAMEA-O16B/Cas9 mRNA/sgRNA nanoparticle effectively accumulates in hepatocytes, and knocks down proprotein convertase subtilisin/kexin type 9 level in mouse serum down to 20% of nontreatment. The leading lipid nanoparticle, BAMEA-O16B, represents one of the most efficient CRISPR/Cas9 delivery nanocarriers reported so far, and it can broaden the therapeutic promise of mRNA and CRISPR/Cas9 technique further.


Assuntos
Proteína 9 Associada à CRISPR/genética , Edição de Genes/métodos , Lipídeos/química , Nanopartículas/química , RNA Guia/química , RNA Mensageiro/química , Animais , Transporte Biológico , Linhagem Celular Tumoral , Técnicas de Silenciamento de Genes/métodos , Técnicas de Transferência de Genes , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Humanos , Camundongos , Oxirredução , Pró-Proteína Convertase 9/genética , Pró-Proteína Convertase 9/metabolismo , RNA Guia/administração & dosagem , RNA Mensageiro/administração & dosagem
10.
Nat Plants ; 5(6): 604-615, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31182845

RESUMO

During phloem unloading, multiple cell-to-cell transport events move organic substances to the root meristem. Although the primary unloading event from the sieve elements to the phloem pole pericycle has been characterized to some extent, little is known about post-sieve element unloading. Here, we report a novel gene, PHLOEM UNLOADING MODULATOR (PLM), in the absence of which plasmodesmata-mediated symplastic transport through the phloem pole pericycle-endodermis interface is specifically enhanced. Increased unloading is attributable to a defect in the formation of the endoplasmic reticulum-plasma membrane tethers during plasmodesmal morphogenesis, resulting in the majority of pores lacking a visible cytoplasmic sleeve. PLM encodes a putative enzyme required for the biosynthesis of sphingolipids with very-long-chain fatty acid. Taken together, our results indicate that post-sieve element unloading involves sphingolipid metabolism, which affects plasmodesmal ultrastructure. They also raise the question of how and why plasmodesmata with no cytoplasmic sleeve facilitate molecular trafficking.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Floema/metabolismo , Plasmodesmos/ultraestrutura , Esfingolipídeos/biossíntese , Arabidopsis/genética , Arabidopsis/ultraestrutura , Proteínas de Arabidopsis/genética , Genes de Plantas , Glucanos/metabolismo , Proteínas de Fluorescência Verde/metabolismo , Mutação , Raízes de Plantas/metabolismo , Plasmodesmos/metabolismo , Transferases (Outros Grupos de Fosfato Substituídos)/genética , Transferases (Outros Grupos de Fosfato Substituídos)/metabolismo
11.
Virol J ; 16(1): 81, 2019 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-31221185

RESUMO

BACKGROUND: Pseudorabies virus (PRV) protein UL56 (pUL56) has been implicated in viral dissemination and virulence in vivo. However, the properties of PRV pUL56 remain largely unknown. In the present study, we aim to investigate the subcellular localization of pUL56 and the underlying molecular basis in transfected cells. METHODS: Constructs of N-terminal green fluorescent protein (GFP) fused pUL56 and its truncations were employed for investigating subcellular localization and further identifying amino acids crucial for pUL56 localization in transfected Vero cells. Finally, the identified amino acids were replaced with alanine for confirming if these mutations could impair the specific localization of pUL56. RESULTS: The pUL56 predominantly localized at the Golgi and trans-Golgi network (TGN) through its predicted C-terminal transmembrane helix in transfected Vero cells. A Golgi-associated protein Rab6a, independent of interaction with pUL56, was significantly downregulated by pUL56. Further, we found three truncated pUL56 C-terminal fragments (174-184, 175-185 and 191-195) could restrict GFP in the perinuclear region, respectively. Within these truncations, the 174proline (P), 181leucine (L), 185L and 191L were essential for maintaining perinuclear accumulation, thus suggesting an important role of leucine. Alanine (A) mutagenesis assays were employed to generate a series of pUL56 C-terminal mutants on the basis of leucine. Finally, a pUL56 mutant M10 (174P/A-177L/A-181L/A-185L/A-191L/A-194L/A-195I/A-196-197L/A-200L/A) lost Golgi-TGN localization. Thus, our data revealed that the leucine-rich transmembrane helix was responsible for pUL56 Golgi-TGN localization and retention, probably through specific intracellular membrane insertion. CONCLUSION: Our data indicated that the C-terminal transmembrane helix was responsible for the Golgi-TGN localization of pUL56. In addition, the leucines within C-terminal transmembrane helix were essential for maintaining pUL56 Golgi-TGN retention in cells. Further, the pUL56 can induce downregulation of Golgi-associated protein Rab6a.


Assuntos
Complexo de Golgi/fisiologia , Leucina/química , Pseudorraiva , Proteínas Estruturais Virais/metabolismo , Rede trans-Golgi/fisiologia , Animais , Cercopithecus aethiops , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Células HEK293 , Humanos , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Transporte Proteico , Transfecção , Células Vero , Proteínas Estruturais Virais/genética
12.
Nat Commun ; 10(1): 2797, 2019 06 26.
Artigo em Inglês | MEDLINE | ID: mdl-31243273

RESUMO

Collective cell migration occurs in many patho-physiological states, including wound healing and invasive cancer growth. The integrity of the expanding epithelial sheets depends on extracellular cues, including cell-cell and cell-matrix interactions. We show that the nano-scale topography of the extracellular matrix underlying epithelial cell layers can strongly affect the speed and morphology of the fronts of the expanding sheet, triggering partial and complete epithelial-mesenchymal transitions (EMTs). We further demonstrate that this behavior depends on the mechano-sensitivity of the transcription regulator YAP and two new YAP-mediated cross-regulating feedback mechanisms: Wilms Tumor-1-YAP-mediated downregulation of E-cadherin, loosening cell-cell contacts, and YAP-TRIO-Merlin mediated regulation of Rho GTPase family proteins, enhancing cell migration. These YAP-dependent feedback loops result in a switch-like change in the signaling and the expression of EMT-related markers, leading to a robust enhancement in invasive cell spread, which may lead to a worsened clinical outcome in renal and other cancers.


Assuntos
Células Epiteliais/fisiologia , Transição Epitelial-Mesenquimal/fisiologia , Nanoestruturas , Proteínas WT1/metabolismo , Proteínas rho de Ligação ao GTP/metabolismo , Proteínas Adaptadoras de Transdução de Sinal , Animais , Cães , Técnicas de Silenciamento de Genes , Proteínas de Fluorescência Verde/metabolismo , Células Madin Darby de Rim Canino , Propriedades de Superfície , Proteínas WT1/genética , Proteínas rho de Ligação ao GTP/genética
13.
Int J Mol Sci ; 20(9)2019 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-31067766

RESUMO

The microbial assimilation of one-carbon (C1) gases is a topic of interest, given that products developed using this pathway have the potential to act as promising substrates for the synthesis of valuable chemicals via enzymatic oxidation or C-C bonding. Despite extensive studies on C1 gas assimilation pathways, their key enzymes have yet to be subjected to high-throughput evolution studies on account of the lack of an efficient analytical tool for C1 metabolites. To address this challenging issue, we attempted to establish a fine-tuned single-cell-level biosensor system constituting a combination of transcription factors (TFs) and several C1-converting enzymes that convert target compounds to the ligand of a TF. This enzymatic conversion broadens the detection range of ligands by the genetic biosensor systems. In this study, we presented new genetic enzyme screening systems (GESSs) to detect formate, formaldehyde, and methanol from specific enzyme activities and pathways, named FA-GESS, Frm-GESS, and MeOH-GESS, respectively. All the biosensors displayed linear responses to their respective C1 molecules, namely, formate (1.0-250 mM), formaldehyde (1.0-50 µM), and methanol (5-400 mM), and they did so with high specificity. Consequently, the helper enzymes, including formaldehyde dehydrogenase and methanol dehydrogenase, were successfully combined to constitute new versatile combinations of the C1-biosensors.


Assuntos
Proteínas de Bactérias/metabolismo , Técnicas Biossensoriais/métodos , Formaldeído/análise , Formiatos/análise , Metanol/análise , Oxirredutases do Álcool/genética , Oxirredutases do Álcool/metabolismo , Aldeído Oxirredutases/genética , Aldeído Oxirredutases/metabolismo , Proteínas de Bactérias/genética , Escherichia coli/genética , Escherichia coli/metabolismo , Genes Reporter , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Fatores de Transcrição
14.
Int J Mol Sci ; 20(9)2019 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-31083521

RESUMO

ADP-ribosylation factor-guanine nucleotide exchange factors (ARF-GEFs) act as key regulators of vesicle trafficking in all eukaryotes. In Arabidopsis, there are eight ARF-GEFs, including three members of the GBF1 subfamily and five members of the BIG subfamily. These ARF-GEFs have different subcellular localizations and regulate different trafficking pathways. Until now, the roles of these BIG-subfamily ARF-GEFs have not been fully revealed. Here, analysis of the BIGs expression patterns showed that BIG3 and BIG5 have similar expression patterns. big5-1 displayed a dwarf growth and big3-1 big5-1 double mutant showed more severe defects, indicating functional redundancy between BIG3 and BIG5. Moreover, both big5-1 and big3-1 big5-1 exhibited a reduced sensitivity to Brassinosteroid (BR) treatment. Brefeldin A (BFA)-induced BR receptor Brassinosteroid insensitive 1 (BRI1) aggregation was reduced in big5-1 mutant, indicating that the action of BIG5 is required for BRI1 recycling. Furthermore, BR-induced dephosphorylation of transcription factor BZR1 was decreased in big3-1 big5-1 double mutants. The introduction of the gain-of-function of BZR1 mutant BZR1-1D in big3-1 big5-1 mutants can partially rescue the big3-1 big5-1 growth defects. Our findings revealed that BIG5 functions redundantly with BIG3 in plant growth and gravitropism, and BIG5 participates in BR signal transduction pathway through regulating BRI1 trafficking.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Arabidopsis/fisiologia , Gravitropismo , Desenvolvimento Vegetal , Proteínas Quinases/metabolismo , Proteínas de Arabidopsis/genética , Brassinosteroides/farmacologia , Teste de Complementação Genética , Gravitropismo/efeitos dos fármacos , Proteínas de Fluorescência Verde/metabolismo , Inflorescência/efeitos dos fármacos , Inflorescência/crescimento & desenvolvimento , Mutação/genética , Fenótipo , Desenvolvimento Vegetal/efeitos dos fármacos , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Transporte Proteico/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos
15.
Int J Mol Sci ; 20(9)2019 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-31083552

RESUMO

Engineering aminoacyl-tRNA synthetases (aaRSs) provides access to the ribosomal incorporation of noncanonical amino acids via genetic code expansion. Conventional targeted mutagenesis libraries with 5-7 positions randomized cover only marginal fractions of the vast sequence space formed by up to 30 active site residues. This frequently results in selection of weakly active enzymes. To overcome this limitation, we use computational enzyme design to generate a focused library of aaRS variants. For aaRS enzyme redesign, photocaged ortho-nitrobenzyl tyrosine (ONBY) was chosen as substrate due to commercial availability and its diverse applications. Diversifying 17 first- and second-shell sites and performing conventional aaRS positive and negative selection resulted in a high-activity aaRS. This MjTyrRS variant carries ten mutations and outperforms previously reported ONBY-specific aaRS variants isolated from traditional libraries. In response to a single in-frame amber stop codon, it mediates the in vivo incorporation of ONBY with an efficiency matching that of the wild type MjTyrRS enzyme acylating cognate tyrosine. These results exemplify an improved general strategy for aaRS library design and engineering.


Assuntos
Aminoacil-tRNA Sintetases/genética , Biologia Computacional/métodos , Biblioteca Gênica , Luz , Tirosina/metabolismo , Domínio Catalítico , Estabilidade Enzimática , Fluorescência , Proteínas de Fluorescência Verde/metabolismo , Mutação/genética , Temperatura Ambiente
16.
Int J Mol Sci ; 20(10)2019 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-31091742

RESUMO

Ceratocystis paradoxa, the causal agent of stem-bleeding disease of the coconut palm, causes great losses to the global coconut industry. As the mechanism of pathogenicity of C. paradoxa has not been determined, an exogenous gene marker was introduced into the fungus. In this study, pCT74-sGFP, which contains the green fluorescent protein (GFP) gene, and the hygromycin B resistance gene as a selective marker, was used as an expression vector. Several protoplast release buffers were compared to optimize protoplast preparation. The plasmid pCT74-sGFP was successfully transformed into the genome of C. paradoxa, which was verified using polymerase chain reaction and green fluorescence detection. The transformants did not exhibit any obvious differences from the wild-type isolates in terms of growth and morphological characteristics. Pathogenicity tests showed that the transformation process did not alter the virulence of the X-3314 C. paradoxa strain. This is the first report on the polyethylene glycol-mediated transformation of C. paradoxa carrying a 'reporter' gene GFP that was stably and efficiently expressed in the transformants. These findings provide a basis for future functional genomics studies of C. paradoxa and offer a novel opportunity to track the infection process of C. paradoxa.


Assuntos
Ascomicetos/genética , Técnicas de Transferência de Genes , Ascomicetos/patogenicidade , Cocos/microbiologia , Vetores Genéticos/genética , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo
17.
Analyst ; 144(12): 3756-3764, 2019 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-31070195

RESUMO

Protein phosphorylation is a very important regulatory mechanism in a majority of biological processes, and the determination of protein kinase activity plays a key role in the pathological study and drug development of kinase-related diseases. However, it is very challenging to in situ study endogenous protein kinase activity in a single living cell due to the shortage of in vivo efficient methods. Here, we propose a new strategy for direct determination of protein kinase activity in a single living cell by combining single molecule fluorescence correlation spectroscopy (FCS) with activity-based probes (ABPs). Ribosomal S6 kinase-2 (RSK2) was used as a model, and the ABPs were synthesized on the basis of RSK2 inhibitor FMK to specially label active RSK2 in living cells. Conventional FCS and MEMFCS (maximum entropy method) single molecule techniques were used to in situ determine RSK2 activity in living cells based on the difference in molecular weight between free probes and probe-RSK2 complexes. Furthermore, wild-type and mutated RSK2 were fused with enhanced green fluorescent protein (EGFP) using lentivirus infection, and fluorescence cross-correlation spectroscopy (FCCS) was used to verify the selective binding of ABPs to RSK2-EGFP fusion protein in living cells. Finally, FCS with ABPs was applied for in situ monitoring of the activation of endogenous RSK2 in the stimulation of serum, epidermal growth factor, kinase inhibitors and ultraviolet irradiation; we observed that endogenous RSK2 showed different behaviors in the cytoplasm and the nucleus in some stimulation. Our results document that FCS with ABPs is a very promising method for studying endogenous protein kinases in living cells.


Assuntos
Ensaios Enzimáticos/métodos , Proteínas Quinases S6 Ribossômicas 90-kDa/análise , Análise de Célula Única/métodos , Espectrometria de Fluorescência/métodos , Compostos de Boro/síntese química , Compostos de Boro/química , Carbocianinas/síntese química , Carbocianinas/química , Linhagem Celular Tumoral , Corantes Fluorescentes/síntese química , Corantes Fluorescentes/química , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Humanos , Mutação , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Proteínas Quinases S6 Ribossômicas 90-kDa/genética , Proteínas Quinases S6 Ribossômicas 90-kDa/metabolismo , Imagem Individual de Molécula/métodos
18.
Int J Nanomedicine ; 14: 2609-2618, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31043777

RESUMO

Background: EGFP-EGF1-conjugated poly(lactic-co-glycolic acid) (PLGA) nanoparticle (ENP) has a specific affinity to tissue factor (TF). The aim of this study was to investigate the target delivery of ENP to plaques and its uptake in a mouse model of atherosclerosis in vivo and in vitro. Materials and methods: Coumarin-6- and 1,1'-dioctadecyl-3,3,3',3'-tetramethylindotricarbo cyanine iodide (DiR)-loaded ENPs were synthesized using a double-emulsion method. Mouse vascular smooth muscle cells (VSMCs) were induced with MCP-1 to obtain an increased TF expression. Fluorescence microscopy and flow cytometry assay were performed to examine the uptake of coumarin-6-loaded ENPs in cellular models. An animal model of atherosclerosis was established with an ApoE (-/-) mouse fed with continuous high-fat diets for 14 weeks. DiR-loaded ENPs (DiR-ENPs) were injected via the caudal vein. The distribution of DiR-ENPs was examined through organ imaging and confocal laser scanning microscopy. Results: Results indicated TFs were highly expressed in the cellular model. The uptake of coumarin-6-loaded ENPs was significantly higher than that of common PLGA nanoparticles. Thickening of intima and lipid deposition in the aorta could be observed in atherosclerosis mouse models. Confocal laser scanning microscopy organ imaging showed ENPs accumulated in vessels with atherosclerotic plaques, which coincided with high expressions of TF. Conclusion: This study showed that EGFP-EGF1-conjugated PLGA nanoparticles could be effectively delivered to atherosclerotic plaques in vivo and taken up by VSMCs with high TF expressions in vitro. Thus, it could be a promising carrier for targeted therapy of atherosclerosis.


Assuntos
Aterosclerose/diagnóstico , Aterosclerose/tratamento farmacológico , Portadores de Fármacos/química , Proteínas de Fluorescência Verde/metabolismo , Nanopartículas/química , Fator G para Elongação de Peptídeos/metabolismo , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Animais , Aorta/patologia , Cumarínicos/química , Modelos Animais de Doenças , Portadores de Fármacos/administração & dosagem , Sistemas de Liberação de Medicamentos , Fluorescência , Humanos , Camundongos Endogâmicos C57BL , Músculo Liso Vascular/citologia , Miócitos de Músculo Liso/metabolismo , Nanopartículas/administração & dosagem , Tamanho da Partícula , Eletricidade Estática , Tiazóis/química
20.
BMC Plant Biol ; 19(1): 191, 2019 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-31072335

RESUMO

BACKGROUND: BRASSINAZOLE-RESISTANT (BZR) family genes encode plant-specific transcription factors (TFs) that participate in brassinosteroid signal transduction. BZR TFs have vital roles in plant growth, including cell elongation. However, little is known about BZR genes in sugar beet (Beta vulgaris L.). RESULTS: Therefore, we performed a genome-wide investigation of BvBZR genes in sugar beet. Through an analysis of the BES1_N conserved domain, six BvBZR gene family members were identified in the sugar beet genome, which clustered into three subgroups according to a phylogenetic analysis. Each clade was well defined by the conserved motifs, implying that close genetic relationships could be identified among the members of each subfamily. According to chromosomal distribution mapping, 2, 1, 1, 1, and 1 genes were located on chromosomes 1, 4, 5, 6, and 8, respectively. The cis-acting elements related to taproot growth were randomly distributed in the promoter sequences of the BvBZR genes. Tissue-specific expression analyses indicated that all BvBZR genes were expressed in all three major tissue types (roots, stems, and leaves), with significantly higher expression in leaves. Subcellular localization analysis revealed that Bv1_fxre and Bv6_nyuw are localized in the nuclei, consistent with the prediction of Wolf PSORT. CONCLUSION: These findings offer a basis to predict the functions of BZR genes in sugar beet, and lay a foundation for further research of the biological functions of BZR genes in sugar beet.


Assuntos
Beta vulgaris/genética , Regulação da Expressão Gênica de Plantas , Genoma de Planta , Fatores de Transcrição/genética , Motivos de Aminoácidos , Beta vulgaris/efeitos dos fármacos , Cromossomos de Plantas/genética , Sequência Conservada/genética , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Genes de Plantas , Proteínas de Fluorescência Verde/metabolismo , Motivos de Nucleotídeos/genética , Filogenia , Reguladores de Crescimento de Planta/farmacologia , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Regiões Promotoras Genéticas , Fatores de Transcrição/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA