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1.
Cell Mol Life Sci ; 80(8): 230, 2023 Jul 27.
Artículo en Inglés | MEDLINE | ID: mdl-37498355

RESUMEN

The aberrant activation of the nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3) inflammasome is known to contribute to the pathogenesis of various human inflammation-related diseases. However, to date, no small-molecule NLRP3 inhibitor has been used in clinical settings. In this study, we have identified SB-222200 as a novel direct NLRP3 inhibitor through the use of drug affinity responsive target stability assay, cellular thermal shift assay, and surface plasmon resonance analysis. SB-222200 effectively inhibits the activation of the NLRP3 inflammasome in macrophages, while having no impact on the activation of NLRC4 or AIM2 inflammasome. Furthermore, SB-222200 directly binds to the NLRP3 protein, inhibiting NLRP3 inflammasome assembly by blocking the NEK7 - NLRP3 interaction and NLRP3 oligomerization. Importantly, treatment with SB-222200 demonstrates alleviation of NLRP3-dependent inflammatory diseases in mouse models, such as monosodium urate crystal-induced peritonitis and dextran sulfate sodium-induced acute intestinal inflammation. Therefore, SB-222200 holds promise as a lead compound for the development of NLRP3 inhibitors to combat NLRP3-driven disease and serves as a versatile tool for pharmacologically investigating NLRP3 biology.


Asunto(s)
Proteína con Dominio Pirina 3 de la Familia NLR , Peritonitis , Ratones , Animales , Humanos , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Inflamasomas/metabolismo , Peritonitis/inducido químicamente , Peritonitis/tratamiento farmacológico , Peritonitis/metabolismo , Macrófagos/metabolismo , Inflamación/metabolismo , Ratones Endogámicos C57BL , Interleucina-1beta/metabolismo
2.
Biotechnol Bioeng ; 120(4): 1133-1146, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36585353

RESUMEN

Engineering biological systems to test new pathway variants containing different enzyme homologs is laborious and time-consuming. To tackle this challenge, a strategy was developed for rapidly prototyping enzyme homologs by combining cell-free protein synthesis (CFPS) with split green fluorescent protein (GFP). This strategy featured two main advantages: (1) dozens of enzyme homologs were parallelly produced by CFPS within hours, and (2) the expression level and activity of each homolog was determined simultaneously by using the split GFP assay. As a model, this strategy was applied to optimize a 3-step pathway for nicotinamide mononucleotide (NMN) synthesis. Ten enzyme homologs from different organisms were selected for each step. Here, the most productive homolog of each step was identified within 24 h rather than weeks or months. Finally, the titer of NMN was increased to 1213 mg/L by improving physiochemical conditions, tuning enzyme ratios and cofactor concentrations, and decreasing the feedback inhibition, which was a more than 12-fold improvement over the initial setup. This strategy would provide a promising way to accelerate design-build-test cycles for metabolic engineering to improve the production of desired products.


Asunto(s)
Enzimas , Ingeniería Metabólica , Mononucleótido de Nicotinamida , Ingeniería Metabólica/métodos , Mononucleótido de Nicotinamida/biosíntesis , Enzimas/química , Enzimas/genética , Proteínas Fluorescentes Verdes/química , Proteínas Fluorescentes Verdes/genética , Vías Biosintéticas
3.
Neurol Sci ; 44(5): 1543-1554, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36781564

RESUMEN

BACKGROUND: Epilepsy is a neurological disease characterized by neural network dysfunction. Although most reports indicate that the pathological process of epilepsy is related to inflammation, synaptic plasticity, cell apoptosis, and ion channel dysfunction, the underlying molecular mechanisms of epilepsy are not fully understood. METHODS: This review summarizes the latest literature on the roles and characteristics of long noncoding RNAs (lncRNAs) in the pathogenesis of epilepsy. RESULTS: lncRNAs are a class of long transcripts without protein-coding functions that perform important regulatory functions in various biological processes. lncRNAs are involved in the regulation of the pathological process of epilepsy and are abnormally expressed in both patients and animal models. This review provides an overview of research progress in epilepsy, the multifunctional features of lncRNAs, the lncRNA expression pattern related to epileptogenesis and status epilepticus, and the potential mechanisms for the two interactions contributing to epileptogenesis and progression. CONCLUSION: lncRNAs can serve as new diagnostic markers and therapeutic targets for epilepsy in the future.


Asunto(s)
Epilepsia , MicroARNs , ARN Largo no Codificante , Animales , ARN Largo no Codificante/genética , ARN Mensajero/metabolismo , Epilepsia/genética , Redes Reguladoras de Genes/genética , MicroARNs/genética
4.
J Fluoresc ; 32(4): 1397-1404, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35438371

RESUMEN

Cadmium contamination is a severe threat to the environment and food safety. Thus, there is an urgent need to develop highly sensitive and selective cadmium detection tools. The engineered fluorescent indicator is a powerful tool for the rapid detection of inorganic cadmium in the environment. In this study, the development of yellow fluorescent indicators of cadmium chloride by inserting a fluorescent protein at different positions of the high cadmium-specific repressor and optimizing the flexible linker between the connection points is reported. These indicators provide a fast, sensitive, specific, high dynamic range, and real-time readout of cadmium ion dynamics in solution. The excitation and emission wavelength of this indicator used in this work are 420/485 and 528 nm, respectively. Fluorescent indicators N0C0/N1C1 showed a linear response to cadmium concentration within the range from 10/30 to 50/100 nM and with a detection limit of 10/33 nM under optimal condition. Escherichia coli cells containing the indicator were used to further study the response of cadmium ion concentration in living cells. E. coli N1C1 could respond to different concentrations of cadmium ions. This study provides a rapid and straightforward method for cadmium ion detection in vitro and the potential for biological imaging.


Asunto(s)
Cadmio , Colorantes Fluorescentes , Escherichia coli/metabolismo , Colorantes Fluorescentes/metabolismo , Iones , Proteínas
5.
Acta Neurol Scand ; 146(6): 743-751, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36000491

RESUMEN

Tuberous sclerosis complex (TSC) is an autosomal dominant neurocutaneous syndrome, with 75.6%-83.5% and 54.1% patients presenting with epilepsy and drug-resistant epilepsy (DRE), respectively. Clinical studies on TSC, particularly surgical interventions, have achieved rapid and substantial progress. The TSC-Task Force Committee of the China Association Against Epilepsy (CAAE-TFTSC) was founded in 2012, and annual academic conferences on the surgical treatment of TSC-related epilepsy have been held since 2013. 'China experts' consensus on surgical treatment of TSC-related epilepsy' was published in 2019. This review focuses on surgical treatment, including resective surgery, neuromodulations, corpus callosotomy and mini-invasive ablations, as well as studies on phenotype, genotype and anti-seizure therapies of mammalian target of rapamycin inhibitor, vigabatrin and ketogenic diet in patients with TSC-related DRE in China.


Asunto(s)
Dieta Cetogénica , Epilepsia Refractaria , Epilepsia , Esclerosis Tuberosa , Humanos , Epilepsia Refractaria/tratamiento farmacológico , Epilepsia/epidemiología , Epilepsia/etiología , Epilepsia/tratamiento farmacológico , Esclerosis Tuberosa/complicaciones
6.
Appl Microbiol Biotechnol ; 106(18): 6317-6333, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-36028635

RESUMEN

Recombinant luminescent Escherichia coli strains could be used to detect the toxicity of pure or mixed contaminants as a light-off sensor. In this work, the lux operon of Photobacterium phosphoreum T3 was identified for the first time. Recombinant luminescent E. coli strains were constructed via expressing the lux operons of P. phosphoreum T3 and Vibrio qinghaiensis Q67 in E. coli MG1655, and the optimal protectant containing 10% (w/v) trehalose and 4% sucrose was used to prepare the freeze-dried recombinant luminescent E. coli cells. Then, these freeze-dried E. coli cells were subjected to acute toxicity detection. The results showed that luminescent E. coli strains displayed sensitive toxic responses to BPA, nFe2O3, Cd, Pb, As, and Hg, for example, the EC50 values of BPA and nFe2O3 to luminescent E. coli strains ranged from 1.54 to 50.19 mg/l and 17.50 to 21.52 mg/l, respectively. Indeed, luminescent E. coli strains exhibited more sensitive responses to Cd, Pb, and Hg than the natural strain Q67. The results suggested that recombinant luminescent E. coli strains could be used for the detection of acute toxicity. Furthermore, the combined toxicities of BPA and nFe2O3, Hg, and Pb were measured, and the joint effects of these mixtures were evaluated with luminescent E. coli. The results indicated that the joint effects of BPA and nFe2O3 suggested to be synergistic or additive to luminescent E. coli, while the joint effects of heavy metals and nFe2O3 exhibited additivities. The cellular endocytosis for Fe2O3 nanoparticles was not observed, which could explain the additive instead of synergistic effects between heavy metals and nFe2O3. KEY POINTS: • Sequence of the lux operon from P. phosphoreum T3 was reported for the first time. • Recombinant luminescent E. coli was more sensitive to Cd, Pb, and Hg than Q67. • Joint effects of BPA and nFe2O3 were synergistic or additive to luminescent E. coli.


Asunto(s)
Mercurio , Metales Pesados , Cadmio , Escherichia coli/genética , Plomo , Mediciones Luminiscentes , Operón , Pruebas de Toxicidad
7.
Neurol Sci ; 43(11): 6471-6478, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-35962929

RESUMEN

OBJECTIVES: The effects of current conduction were researched to confirm that it can decrease focal epileptogenicity in patients with temporal lobe epilepsy (TLE). METHODS: Data from 13 patients with mesial TLE were collected. After no less than two habitual seizures were captured during stereo-electroencephalogram monitoring, current conduction was measured in the hippocampus to a homemade, zero potential circuit board. The interictal spike, ripple, fast ripple, and ictal epileptogenicity index (EI) changes were analyzed in the hippocampus, amygdala, and anterior and middle temporal neocortex regions. RESULTS: Significant differences were found in the percentage of patients without spikes in the temporal neocortex between pre- and post-current conduction. Significant decreases in average ripple rates were found in the hippocampus and amygdala after current conduction. The percentage of fast ripple rate decrease in the hippocampus and amygdala was significantly higher than that in the temporal neocortex, and significant decreases were found in the fast ripple rate in the hippocampus from post- to pre-current conduction. Significant decreases were found in the EI values after current conduction in the amygdala and middle temporal lobe compared to the EI values before current conduction. CONCLUSION: After current conduction in patients with TLE, the spike rate decreases in the hippocampus, amygdala, and anterior and middle temporal neocortex, the ripple rate decreases in the hippocampus and amygdala, the fast ripple decreases in the hippocampus, and the EI decreases in the amygdala and middle temporal neocortex. Current conduction can reduce epileptogenicity in the hippocampus in mesial TLE.


Asunto(s)
Epilepsia del Lóbulo Temporal , Humanos , Epilepsia del Lóbulo Temporal/complicaciones , Epilepsia del Lóbulo Temporal/diagnóstico por imagen , Lóbulo Temporal/diagnóstico por imagen , Amígdala del Cerebelo/diagnóstico por imagen , Electroencefalografía , Hipocampo/diagnóstico por imagen , Imagen por Resonancia Magnética
8.
NMR Biomed ; 34(9): e4565, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34061413

RESUMEN

Few in vivo studies have focused on the perivenous association of tubers and iron deposition in the deep gray nuclei in patients with tuberous sclerosis complex (TSC). We investigated this possible relationship in TSC patients using susceptibility weighted imaging (SWI) at 7 T. SWI with high spatial resolution and enhanced sensitivity was performed on 11 TSC patients in comparison with 15 age- and sex-matched healthy controls. The relationship between tubers and veins was evaluated. In addition, the phase images of SWI were processed to produce local field shift (LFS) maps to quantify iron deposition. The mean LFS in the deep gray nuclei was compared between the TSC patients and healthy controls using a covariance analysis. Venous involvement was observed in 211 of the 231 (91.3%) cortical tubers on SWI. The slender tubers often oriented around the long axis of penetrating veins, possibly because cortical tubers typically developed and/or migrated along venous vasculatures. A significant difference in LFS of the thalamus was detected between the TSC patients and healthy controls (3.36 ± 0.50 versus 3.01 ± 0.39, p < 0.01). The new in vivo imaging features observed at 7 T provide valuable insights into the possible venous association of TSC lesions and iron accumulation in the deep gray nuclei. Our results may lead to a better understanding of the pathological changes involved in TSC under in vivo conditions.


Asunto(s)
Imagen por Resonancia Magnética , Esclerosis Tuberosa/diagnóstico por imagen , Adolescente , Adulto , Factores de Edad , Encéfalo/diagnóstico por imagen , Encéfalo/patología , Estudios de Casos y Controles , Niño , Imagen de Difusión por Resonancia Magnética , Susceptibilidad a Enfermedades , Femenino , Humanos , Masculino , Esclerosis Tuberosa/patología , Adulto Joven
9.
Brain ; 143(2): 570-581, 2020 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-31953931

RESUMEN

At least 50% of patients with tuberous sclerosis complex present with intractable epilepsy; for these patients, resective surgery is a treatment option. Here, we report a nationwide multicentre retrospective study and analyse the long-term seizure and neuropsychological outcomes of epilepsy surgery in patients with tuberous sclerosis complex. There were 364 patients who underwent epilepsy surgery in the study. Patients' clinical data, postoperative seizure outcomes at 1-, 4-, and 10-year follow-ups, preoperative and postoperative intelligence quotients, and quality of life at 1-year follow-up were collected. The patients' ages at surgery were 10.35 ± 7.70 years (range: 0.5-47). The percentage of postoperative seizure freedom was 71% (258/364) at 1-year, 60% (118/196) at 4-year, and 51% (36/71) at 10-year follow-up. Influence factors of postoperative seizure freedom were the total removal of epileptogenic tubers and the presence of outstanding tuber on MRI at 1- and 4-year follow-ups. Furthermore, monthly seizure (versus daily seizure) was also a positive influence factor for postoperative seizure freedom at 1-year follow-up. The presence of an outstanding tuber on MRI was the only factor influencing seizure freedom at 10-year follow-up. Postoperative quality of life and intelligence quotient improvements were found in 43% (112/262) and 28% (67/242) of patients, respectively. Influence factors of postoperative quality of life and intelligence quotient improvement were postoperative seizure freedom and preoperative low intelligence quotient. The percentage of seizure freedom in the tuberectomy group was significantly lower compared to the tuberectomy plus and lobectomy groups at 1- and 4-year follow-ups. In conclusion, this study, the largest nationwide multi-centre study on resective epilepsy surgery, resulted in improved seizure outcomes and quality of life and intelligence quotient improvements in patients with tuberous sclerosis complex. Seizure freedom was often achieved in patients with an outstanding tuber on MRI, total removal of epileptogenic tubers, and tuberectomy plus. Quality of life and intelligence quotient improvements were frequently observed in patients with postoperative seizure freedom and preoperative low intelligence quotient.


Asunto(s)
Epilepsia Refractaria/cirugía , Epilepsia/cirugía , Convulsiones/cirugía , Esclerosis Tuberosa/cirugía , Adolescente , Adulto , Niño , Preescolar , China , Electroencefalografía/métodos , Femenino , Humanos , Lactante , Masculino , Persona de Mediana Edad , Calidad de Vida , Estudios Retrospectivos , Resultado del Tratamiento , Adulto Joven
10.
Stereotact Funct Neurosurg ; 99(3): 212-220, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33311023

RESUMEN

BACKGROUND: Focal cortical dysplasia (FCD) is one of the most important pathogenic findings in patients with extratemporal lobe epilepsy. Magnetic resonance imaging (MRI)-negative is the most important negative factor to predict postoperative seizure freedom; however, FCD-I and part of FCD-IIa are MRI-negative on routine MRI. OBJECTIVES: To explore the diagnostic values of 7T MRI and its new scan sequences in epilepsy patients with FCD-IIa. METHODS: To include patients with focal seizure and suspicious focal abnormal imaging on 3T MRI during preoperative evaluation and perform a 7T MRI scan with white matter-suppressed (WMS) and gray-white matter tissue border enhancement (GWBE) sequences, resective epilepsy surgery, and postoperative pathological finding of FCD-IIa. The preoperative qualitative and localization significance of 7T MRI and 3T MRI in lesions with FCD-IIa was compared, and then, the imaging characteristics of lesions with FCD-IIa on 7T MRI were analyzed. RESULTS: Ten cases were enrolled in this study. Seven tesla MRI presented high spatial resolutions and a high signal-to-noise ratio. WMS and GWBE could selectively suppress the signal of special tissue and improved the possibility of FCD findings. FCD-IIa showed abnormal thickness of gray matter and a blurring border and was hypointense on 7T MRI compared with 3T MRI. Seven patients showed improvement in the qualitative diagnosis strength grade of FCD, and 6 subjects showed improvement in the localization strength grade of the lesion border after careful reading of the 7T MR images. Significant differences were found in the qualitative diagnosis of FCD (p < 0.05) and localization of the lesion border (p < 0.05) between the neuroimaging diagnoses based on 3T MRI and the findings based on 7T MRI. CONCLUSION: 7T MRI with WMS and GWBE sequences shows application value in the preoperative imaging diagnosis of lesions with FCD-IIa in epilepsy patients.


Asunto(s)
Epilepsias Parciales , Epilepsia , Malformaciones del Desarrollo Cortical , Sustancia Blanca , Epilepsia/diagnóstico por imagen , Humanos , Imagen por Resonancia Magnética , Malformaciones del Desarrollo Cortical/diagnóstico por imagen , Malformaciones del Desarrollo Cortical/cirugía
11.
Biochem Biophys Res Commun ; 527(1): 276-282, 2020 06 18.
Artículo en Inglés | MEDLINE | ID: mdl-32446380

RESUMEN

Sodium dodecyl sulfate (SDS), a representative anionic surfactant, is a commonly used reagent in studies of the cell membrane and cell wall. However, the mechanisms through which SDS affects cellular functions have not yet been fully examined. Thus, to gain further insights into the cellular functions and responses to SDS, we tested a haploid library of Saccharomyces cerevisiae single-gene deletion mutants to identify genes required for tolerance to SDS. After two rounds of screening, we found 730 sensitive and 77 resistant mutants. Among the sensitive mutants, mitochondrial gene expression; the mitogen-activated protein kinase signaling pathway; the metabolic pathways involved in glycoprotein, lipid, purine metabolic process, oxidative phosphorylation, cellular amino acid biosynthesis and pentose phosphate pathway were found to be enriched. Additionally, we identified a set of transcription factors related to SDS responses. Among the resistant mutants, disruption of ribosome biogenesis and translation alleviated SDS-induced cytotoxicity. Collectively, our results provided new insights into the mechanisms through which SDS regulates the cell membrane or cell wall.


Asunto(s)
Membrana Celular/efectos de los fármacos , Pared Celular/efectos de los fármacos , Saccharomyces cerevisiae/efectos de los fármacos , Dodecil Sulfato de Sodio/farmacología , Tensoactivos/farmacología , Membrana Celular/metabolismo , Pared Celular/metabolismo , Biología Computacional , Saccharomyces cerevisiae/metabolismo
12.
BMC Microbiol ; 20(1): 262, 2020 08 24.
Artículo en Inglés | MEDLINE | ID: mdl-32838766

RESUMEN

BACKGROUND: Glycosylphosphatidylinositol (GPI)-anchored glycoproteins have diverse intrinsic functions in yeasts, and they also have different uses in vitro. In this study, the functions of potential GPI proteins in Pichia pastoris were explored by gene knockout approaches. RESULTS: Through an extensive knockout of GPI proteins in P. pastoris, a single-gene deletion library was constructed for 45 predicted GPI proteins. The knockout of proteins may lead to the activation of a cellular response named the 'compensatory mechanism', which is characterized by changes in the content and relationship between cell wall polysaccharides and surface proteins. Among the 45 deletion strains, five showed obvious methanol tolerance, four owned high content of cell wall polysaccharides, and four had a high surface hydrophobicity. Some advantages of these strains as production hosts were revealed. Furthermore, the deletion strains with high surface hydrophobicity were used as hosts to display Candida antarctica lipase B (CALB). The strain gcw22Δ/CALB-GCW61 showed excellent fermentation characteristics, including a faster growth rate and higher hydrolytic activity. CONCLUSIONS: This GPI deletion library has some potential applications for production strains and offers a valuable resource for studying the precise functions of GPI proteins, especially their putative functions.


Asunto(s)
Proteínas Fúngicas/metabolismo , Proteínas Ligadas a GPI/genética , Técnicas de Inactivación de Genes/métodos , Lipasa/metabolismo , Pichia/crecimiento & desarrollo , Fermentación , Proteínas Fúngicas/genética , Eliminación de Gen , Biblioteca de Genes , Ingeniería Genética , Hidrólisis , Lipasa/genética , Pichia/genética , Pichia/metabolismo
13.
Biosci Biotechnol Biochem ; 84(3): 463-470, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31752618

RESUMEN

Lycopene is a highly valued carotenoid with wide applications in various industries. The market demand for lycopene promotes research in metabolic engineering of heterologous hosts for lycopene. In this study, Pichia pastoris strain GS115 was genetically engineered to produce lycopene by integrating the heterologous lycopene biosynthesis genes from Corynebacterium glutamicum ATCC13032. The resulting strain, L1, produced 0.115 mg/g cell dry weight (DCW) lycopene. Through optimization by promoter selection, improving the precursor supply and expanding the Geranylgeranyl diphosphate (GGPP) pool, ultimately, the lycopene yield of the final optimal strain was 6.146 mg/g DCW with shake flask fermentation and 9.319 mg/g DCW (0.714 g/L) in a 3 L fermenter. The lycopene yield in this study is the highest yield of lycopene in P. pastoris reported to date, which demonstrated the potential of P. pastoris in lycopene synthesis and as a candidate host organism for the synthesis of other high value-added terpenoids.


Asunto(s)
Licopeno/metabolismo , Ingeniería Metabólica , Pichia/genética , Reactores Biológicos , Corynebacterium glutamicum/genética , Fermentación
14.
Biotechnol Lett ; 42(12): 2703-2709, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-32808199

RESUMEN

OBJECTIVES: To build a stronger Pichia pastoris PCAT1 promoter and to identify putative transcriptional factor binding sites (TFBSs) on PCAT1 that affect the activity of the promoter. RESULT: A synthetic library of PCAT1 was generated by deleting or duplicating putative TFBS motifs in the promoter sequence. CSRE, MIG1, RAP1 and HAP2/3/4 were found to have important effects on PCAT1 activity. The PCAT1 variant P4 with a putative binding site of RAP1 on the promoter sequence showed a stronger activity compared with that of the wild-type PCAT1 and PAOX1, which is the strongest natural P. pastoris promoter that has been reported. This inference was confirmed with EGFP (enhanced green fluorescent protein) and Candida Antarctica lipase B as the reporters. CONCLUSION: The role of the transcriptional regulator RAP1 may be important in PCAT1 methanol induction. A stronger PCAT1 variant can be constructed by the duplication of the putative binding site of RAP1 on the PCAT1 promoter sequence. This PCAT1 variant has potential value for heterologous protein production, metabolic engineering, and synthetic biology.


Asunto(s)
Catalasa/genética , Ingeniería Genética , Ingeniería Metabólica , Regiones Promotoras Genéticas/genética , Sitios de Unión/genética , Catalasa/química , Regulación Fúngica de la Expresión Génica/genética , Unión Proteica/genética , Saccharomycetales/genética , Biología Sintética , Factores de Transcripción/química , Factores de Transcripción/genética
15.
Biotechnol Lett ; 42(12): 2685-2692, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-32737719

RESUMEN

OBJECTIVE: Translational regulation plays an important role in protein synthesis. Our goal was to screen translation-related factors to improve heterologous protein expression in Pichia pastoris. RESULTS: Twenty-eight translation-related factors were overexpressed in P. pastoris GS115 expressing enhanced green fluorescent protein (eGFP). The results showed that overexpression of Bcy1, the regulatory subunit of protein kinase A (PKA), significantly increased both eGFP expression and cell biomass by 20% under methanol induction for 120 h. Additionally, overexpression of Bcy1 elevated the growth rate by 18% and increased production of the industrial enzyme Phytase (Phy) by 26%. Transcriptome analysis indicated that the overall expression of ribosomal protein genes was significantly downregulated and that postdiauxic shift genes and stress response element genes were upregulated. CONCLUSIONS: Bcy1 regulates ribosome protein genes, postdiauxic shift genes and stress response element genes, leading to improved cell growth and heterologous protein expression. This study provides a convenient and universal factor for heterologous protein production.


Asunto(s)
Proteínas Quinasas Dependientes de AMP Cíclico/genética , Biosíntesis de Proteínas/genética , Subunidades de Proteína/genética , Saccharomycetales/genética , 6-Fitasa/genética , Perfilación de la Expresión Génica , Regulación Enzimológica de la Expresión Génica/genética , Metanol , Proteínas Recombinantes , Saccharomycetales/enzimología
16.
J Ind Microbiol Biotechnol ; 47(4-5): 395-402, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32303871

RESUMEN

The biodesulfurization 4S pathway can specifically desulfurize an aromatic S heterocyclic compound (which is difficult to desulfurize by hydrodesulfurization) and maintain the integrity of its combustion value. The four Dsz enzymes in the pathway convert the model compound dibenzothiophene (DBT) into the sulfur-free compound 2-hydroxybiphenyl (HBP). DszC is the first enzyme in the 4S pathway and is subject to feedback inhibition and substrate inhibition. This study is the first attempt to further modify the DszC mutant AKWC to improve its tolerance to DBT. Alanine scanning was performed on the dimeric surface of the DszC mutant AKWC, and the HBP yield of the BAD (AKWCP413A) strain was increased compared to the BAD (AKWC) strain. Site-directed saturation mutagenesis was performed on the 413th amino acid of AKWC, and the substrate inhibition parameter KI value of the mutant AKWCPI was 5.6 times higher than that of AKWC. When the DBT concentration was 0.25 mM, the HBP production of the recombinant strain overexpressing AKWCPI was increased by approximately 1.4-fold compared to the BL21(DE3)/BADC*+C* strain. The protein engineering of DszC further improved the substrate tolerance after overcoming the feedback inhibition, which provided a reference for the analysis of the inhibition mechanism of DszC substrate. Overexpression of DszC-beneficial mutants also greatly improved the efficiency of desulfurization.


Asunto(s)
Alanina/metabolismo , Proteínas Bacterianas/metabolismo , Mutagénesis , Proteínas Bacterianas/química , Proteínas Bacterianas/genética , Modelos Moleculares , Estructura Terciaria de Proteína , Tiofenos/farmacología
17.
Biochem Biophys Res Commun ; 518(1): 1-6, 2019 10 08.
Artículo en Inglés | MEDLINE | ID: mdl-31427087

RESUMEN

We screened a haploid library of Saccharomyces cerevisiae single-gene deletion mutants to identify nonessential genes associated with increased sensitivity to or resistance against the cell wall antagonist calcofluor white. Through a genome-wide screen, we isolated 537 strains that had an altered growth rate relative to wild type, of which 485 showed increased sensitivity and 52 showed increased resistance to calcofluor white. The MAPK signaling pathway, N-glycan biosynthesis, endocytosis, vacuole acidification, autophagy, and the sulfur relay system were identified as being associated with calcofluor white sensitivity. Resistance genes were mainly involved in chitin metabolism and the RIM101 pathway or encoded several components of the ESCRT complexes or related to cysteine and methionine metabolism and RNA degradation. Further investigation indicated a clear global response network that S. cerevisiae relies on in the presence of the cell wall antagonist calcofluor white, which may help us to understand fungal cell wall remodeling and the mechanisms of toxicity of calcofluor white with respect to eukaryotic cells.


Asunto(s)
Bencenosulfonatos/farmacología , Pared Celular/metabolismo , Eliminación de Gen , Pruebas Genéticas , Genoma Fúngico , Saccharomyces cerevisiae/citología , Saccharomyces cerevisiae/genética , Adaptación Fisiológica/efectos de los fármacos , Adaptación Fisiológica/genética , Pared Celular/efectos de los fármacos , Genes Fúngicos , Mapeo de Interacción de Proteínas , Saccharomyces cerevisiae/efectos de los fármacos
18.
Microb Cell Fact ; 18(1): 207, 2019 Nov 29.
Artículo en Inglés | MEDLINE | ID: mdl-31783868

RESUMEN

BACKGROUND: The methylotrophic yeast Pichia pastoris is well-known for the production of a broad spectrum of functional types of heterologous proteins including enzymes, antigens, engineered antibody fragments, and next gen protein scaffolds and many transcription factors are utilized to address the burden caused by the high expression of heterologous proteins. In this article, a novel P. pastoris transcription factor currently annotated as Fhl1p, an activator of ribosome biosynthesis processing, was investigated for promoting the expression of the recombinant proteins. RESULTS: The function of Fhl1p of P. pastoris for improving the expression of recombinant proteins was verified in strains expressing phytase, pectinase and mRFP, showing that the productivity was increased by 20-35%. RNA-Seq was used to study the Fhl1p regulation mechanism in detail, confirming Fhl1p involved in the regulation of rRNA processing genes, ribosomal small/large subunit biogenesis genes, Golgi vesicle transport genes, etc., which contributed to boosting the expression of foreign proteins. The overexpressed Fhl1p strain exhibited increases in the polysome and monosome levels, showing improved translation activities. CONCLUSION: This study illustrated that the transcription factor Fhl1p could effectively enhance recombinant protein expression in P. pastoris. Furthermore, we provided the evidence that overexpressed Fhl1p was related to more active translation state.


Asunto(s)
Proteínas Fúngicas/metabolismo , Pichia/metabolismo , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/genética , Proteínas Fúngicas/genética , Pichia/genética
19.
Clin Auton Res ; 29(2): 195-204, 2019 04.
Artículo en Inglés | MEDLINE | ID: mdl-30328033

RESUMEN

OBJECTIVE: Epilepsy and seizures can have dramatic effects on cardiac function. The aim of the present study was to investigate deceleration capacity, acceleration capacity and their 24-h fluctuations of heart rate variability in patients with drug-resistant epilepsy. METHODS: Deceleration capacity, acceleration capacity of heart rate and their 24-h dynamics derived from the phase rectified signal averaging method as well as traditional measures were analyzed in 39 patients with drug-resistant epilepsy and 33 healthy control subjects using 24-h electrocardiogram recordings. The discriminatory power of heart rate variability measures were validated by assessment of the area under the receiver operating characteristic curve. Net reclassification improvement and integrated discrimination improvement models were also estimated. RESULTS: Both deceleration capacity and absolute values of acceleration capacity were significantly lower in patients with drug-resistant epilepsy. The abnormal suppression of absolute deceleration capacity and acceleration capacity values were observed throughout the 24-h recording time (peaked at about 3 to 5 A.M.). Deceleration capacity had the greatest discriminatory power to differentiate the patients from the healthy controls. Moreover, in both net reclassification improvement and integrated discrimination improvement models, the combination of acceleration capacity or deceleration capacity with traditional heart rate variability measures has greater discriminatory power than any of the single heart rate variability features. INTERPRETATION: Drug-resistant epilepsy was associated with a significant inhibition of vagal modulation of heart rate, which was more pronounced during the night than during the day. These findings indicate that phase rectified signal averaging method may serve as a complementary approach for characterizing and understanding the neuro-pathophysiology in epilepsy, and may provide a new clue to sudden unexpected death in epilepsy.


Asunto(s)
Epilepsia Refractaria/fisiopatología , Frecuencia Cardíaca/fisiología , Adulto , Electrocardiografía , Femenino , Humanos , Masculino , Adulto Joven
20.
Biotechnol Lett ; 41(12): 1423-1431, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31650421

RESUMEN

OBJECTIVE: The purpose of this article is to study the underlying cause of the induction of autophagy in Pichia pastoris cells grown in amino acid-rich methanol medium during methanol adaptation. RESULTS: Autophagy was induced in P. pastoris GS115 when cells were grown in amino acid-rich methanol medium. Transcriptome analysis revealed that genes involved in amino acid biosynthesis were upregulated. The deletion of Gcw13, a GPI-anchored protein that plays a role in the endocytosis of the general amino acid permease Gap1, resulted in the inhibition of autophagy, the activation of TORC1 and an increase in the uptake of glutamine and asparagine in methanol-grown cells. CONCLUSIONS: Our results demonstrated that the autophagy induced in P. pastoris cells grown in amino acid-rich methanol medium was nitrogen source independent and may be due to a Gcw13-dependent decrease in amino acid uptake during methanol adaptation.


Asunto(s)
Aminoácidos/metabolismo , Autofagia , Proteínas Fúngicas/metabolismo , Metanol/metabolismo , Pichia/crecimiento & desarrollo , Pichia/genética , Eliminación de Secuencia , Sistemas de Transporte de Aminoácidos/metabolismo , Medios de Cultivo/química , Proteínas Fúngicas/genética , Perfilación de la Expresión Génica , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo
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