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1.
Gene ; 806: 145929, 2022 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-34461150

RESUMO

The body color of Neocaridina denticulate sinensis is a compelling phenotypic trait, in which a cascade of carotenoid metabolic processes plays an important role. The study was conducted to compare the transcriptome of cephalothoraxes among three pigmentation phenotypes (red, blue, and chocolate) of N. denticulate sinensis. The purpose of this study was to explore the candidate genes associated with different colors of N. denticulate sinensis. Nine cDNA libraries in three groups were constructed from the cephalothoraxes of shrimps. After assembly, 75022 unigenes were obtained in total with an average length of 1026 bp and N50 length of 1876 bp. There were 45977, 25284, 23605, 21913 unigenes annotated in the Nr, Swissprot, KOG, and KEGG databases, respectively. Differential expression analysis revealed that there were 829, 554, and 3194 differentially expressed genes (DEGs) in RD vs BL, RD vs CH, and BL vs CH, respectively. These DEGs may play roles in the absorption, transport, and metabolism of carotenoids. We also emphasized that electron transfer across the inner mitochondrial membrane (IMM) was a key process in pigment metabolism. In addition, a total of 6328 simple sequence repeats (SSRs) were also detected in N. denticulate sinensis. The results laid a solid foundation for further research on the molecular mechanism of integument pigmentation in the crustacean and contributed to developing more attractive aquatic animals.


Assuntos
Proteínas de Artrópodes/genética , Carotenoides/metabolismo , Decápodes/genética , Pigmentação/genética , Transcriptoma , Animais , Organismos Aquáticos , Proteínas de Artrópodes/classificação , Proteínas de Artrópodes/metabolismo , Transporte Biológico , Cor , Bases de Dados Genéticas , Decápodes/anatomia & histologia , Decápodes/metabolismo , Água Doce , Regulação da Expressão Gênica , Biblioteca Gênica , Ontologia Genética , Repetições de Microssatélites , Mitocôndrias/metabolismo , Membranas Mitocondriais/metabolismo , Anotação de Sequência Molecular , Característica Quantitativa Herdável
2.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 33(4): 380-386, 2021 Aug 24.
Artigo em Chinês | MEDLINE | ID: mdl-34505445

RESUMO

OBJECTIVE: To construct a cDNA library of Sparganum mansoni and immunoscreen antigen candidates for immunodiagnosis of sparganosis mansoni. METHODS: Total RNA was extracted from S. mansoni, and reversely transcribed into cDNA, which was ligated into the phage vector. These recombinant vectors were packaged in vitro to construct the SMART cDNA library of S. mansoni. Then, the cDNA library was immunoscreened with sera from patients with sparganosis mansoni to yield positive clones. The inserted fragments of positive clones were sequenced and subjected to homology analyses, and the structure and functions of the coding proteins were predicted. RESULTS: The SMATR cDNA library of S. mansoni was successfully constructed. The titer of the cDNA library was 6.25 × 106 pfu/mL, with a recombinant efficiency of 100%, and the mean length of the inserted fragments in the library was larger than 1 100 bp. A total of 12 positive clones were obtained by immunoscreening, and were categorized into Sm-I (Sm60-1), Sm-II (Sm58-1), Sm-III (Sm20-1) and Sm-IV (Sm22-3), with 1 134, 1 063, 883 bp and 969 bp long inserted fragments. Their coding proteins were highly homologous with the Spirometra erinaceieuropaei antigenic polypeptide, cytoplasmic antigen, ribosomal protein S4-like protein and unnamed protein product, respectively. CONCLUSIONS: A SMART cDNA library of S. mansoni has been successfully constructed and 4 categories of positive clones have been identified, which provides a basis for further studies on diagnostic antigens for sparganosis mansoni.


Assuntos
Esparganose , Plerocercoide , Animais , Sequência de Bases , DNA Complementar/genética , Biblioteca Gênica , Humanos
3.
Int J Mol Sci ; 22(16)2021 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-34445412

RESUMO

Even in a natural ecosystem, plants are continuously threatened by various microbial diseases. To save themselves from these diverse infections, plants build a robust, multilayered immune system through their natural chemical compounds. Among the several crucial bioactive compounds possessed by plants' immune systems, antimicrobial peptides (AMPs) rank in the first tier. These AMPs are environmentally friendly, anti-pathogenic, and do not bring harm to humans. Antimicrobial peptides can be isolated in several ways, but recombinant protein production has become increasingly popular in recent years, with the Escherichia coli expression system being the most widely used. However, the efficacy of this expression system is compromised due to the difficulty of removing endotoxin from its system. Therefore, this review suggests a high-throughput cDNA library-based plant-derived AMP isolation technique using the Bacillus subtilis expression system. This method can be performed for large-scale screening of plant sources to classify unique or homologous AMPs for the agronomic and applied field of plant studies. Furthermore, this review also focuses on the efficacy of plant AMPs, which are dependent on their numerous modes of action and exceptional structural stability to function against a wide range of invaders. To conclude, the findings from this study will be useful in investigating how novel AMPs are distributed among plants and provide detailed guidelines for an effective screening strategy of AMPs.


Assuntos
Plantas/metabolismo , Proteínas Citotóxicas Formadoras de Poros/isolamento & purificação , Engenharia de Proteínas/métodos , Bacillus subtilis/genética , Bacillus subtilis/crescimento & desenvolvimento , Biblioteca Gênica , Humanos , Proteínas de Plantas/genética , Proteínas de Plantas/isolamento & purificação , Plantas/genética , Proteínas Citotóxicas Formadoras de Poros/genética , Proteínas Citotóxicas Formadoras de Poros/farmacologia
4.
Anim Sci J ; 92(1): e13622, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34418237

RESUMO

This study was carried out with the objective to identify function prediction of novel microRNAs (miRNAs) in immature boar Sertoli cells (SCs) treated with 5-aminoimidazole-4-carboxamide-1-ß-D-ribofuranoside (AICAR), which is an agonist of adenosine monophosphate-activated protein kinase (AMPK) for regulating cellular energy homeostasis. Two small RNA libraries (control and AICAR treatment) prepared from immature boar SCs were constructed and sequenced by the Illumina small RNA deep sequencing. We identified 77 novel miRNAs and predicted 177 potential target genes for 26 differential novel miRNAs (four miRNAs up-regulation and 22 miRNAs down-regulation) in AICAR-treated SCs. Gene Ontology enrichment and Kyoto Encyclopedia of Genes and Genomes pathway suggested that target genes of differential novel miRNAs were implicated in many biological processes and metabolic pathways. Our findings provided useful information for the functional regulation of novel miRNAs and target mRNAs on AMPK-activated immature boar SCs.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Fenômenos Biológicos/genética , MicroRNAs/genética , MicroRNAs/fisiologia , Células de Sertoli/metabolismo , Aminoimidazol Carboxamida/análogos & derivados , Aminoimidazol Carboxamida/farmacologia , Animais , Metabolismo Energético/genética , Biblioteca Gênica , Sequenciamento de Nucleotídeos em Larga Escala/veterinária , Homeostase/genética , Masculino , MicroRNAs/isolamento & purificação , Ribonucleotídeos/farmacologia , Suínos
5.
Nat Cell Biol ; 23(8): 834-845, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34354236

RESUMO

Pioneer transcription factors such as OCT4 can target silent genes embedded in nucleosome-dense regions. How nucleosome interaction enables transcription factors to target chromatin and determine cell identity remains elusive. Here, we systematically dissect OCT4 to show that nucleosome binding is encoded within the DNA-binding domain and yet can be uncoupled from free-DNA binding. Furthermore, accelerating the binding kinetics of OCT4 to DNA enhances nucleosome binding. In cells, uncoupling nucleosome binding diminishes the ability of OCT4 to individually access closed chromatin, while more dynamic nucleosome binding results in expansive genome scanning within closed chromatin. However, both uncoupling and enhancing nucleosome binding are detrimental to inducing pluripotency from differentiated cells. Remarkably, stable interactions between OCT4 and nucleosomes are continuously required for maintaining the accessibility of pluripotency enhancers in stem cells. Our findings reveal how the affinity and residence time of OCT4-nucleosome complexes modulate chromatin accessibility during cell fate changes and maintenance.


Assuntos
Nucleossomos/metabolismo , Fator 3 de Transcrição de Octâmero/fisiologia , Células-Tronco Pluripotentes/fisiologia , Animais , Sítios de Ligação/genética , Cromatina/metabolismo , Elementos Facilitadores Genéticos , Feminino , Fibroblastos , Biblioteca Gênica , Humanos , Camundongos , Modelos Moleculares , Mutação , Fator 3 de Transcrição de Octâmero/genética , Ligação Proteica , Fatores de Transcrição SOXB1/metabolismo
6.
Methods Mol Biol ; 2351: 41-65, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34382183

RESUMO

Enhancers are transcribed by RNA polymerase II (Pol II). In order to study the regulation of enhancer transcription and its function in target gene control, methods are required that track genome transcription with high precision in vivo. Here, we provide step-by-step guidance for performing native elongating transcript sequencing (NET-Seq) in mammalian cells. NET-Seq allows quantitative measurements of transcription genome-wide, including enhancer transcription, with single-nucleotide and DNA strand resolution. The approach consists of capturing and efficiently converting the 3'-ends of the nascent RNA into a sequencing library followed by next-generation sequencing and computational data analysis. The protocol includes quality control measurements to monitor the success of the main steps. Following this protocol, a NET-Seq library is obtained within 5 days.


Assuntos
Elementos Facilitadores Genéticos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Análise de Sequência de RNA/métodos , Transcrição Genética , Animais , Células Cultivadas , Cromatina/genética , Biologia Computacional/métodos , DNA , Biblioteca Gênica , Humanos , Reação em Cadeia da Polimerase , RNA , RNA Polimerase II/metabolismo , Software
7.
Methods Mol Biol ; 2351: 67-90, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34382184

RESUMO

The Cap Analysis of Gene Expression (CAGE) is a powerful method to identify Transcription Start Sites (TSSs) of capped RNAs while simultaneously measuring transcripts expression level. CAGE allows mapping at single nucleotide resolution at all active promoters and enhancers. Large CAGE datasets have been produced over the years from individual laboratories and consortia, including the Encyclopedia of DNA Elements (ENCODE) and Functional Annotation of the Mammalian Genome (FANTOM) consortia. These datasets constitute open resource for TSS annotations and gene expression analysis. Here, we provide an experimental protocol for the most recent CAGE method called Low Quantity (LQ) single strand (ss) CAGE "LQ-ssCAGE", which enables cost-effective profiling of low quantity RNA samples. LQ-ssCAGE is especially useful for samples derived from cells cultured in small volumes, cellular compartments such as nuclear RNAs or for samples from developmental stages. We demonstrate the reproducibility and effectiveness of the method by constructing 240 LQ-ssCAGE libraries from 50 ng of THP-1 cell extracted RNAs and discover lowly expressed novel enhancer and promoter-derived lncRNAs.


Assuntos
Biologia Computacional/métodos , Elementos Facilitadores Genéticos , Regiões Promotoras Genéticas , Capuzes de RNA , Sítio de Iniciação de Transcrição , Bases de Dados Genéticas , Regulação da Expressão Gênica , Biblioteca Gênica , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Anotação de Sequência Molecular , Sequências Reguladoras de Ácido Nucleico , Reprodutibilidade dos Testes , Fluxo de Trabalho
8.
Methods Mol Biol ; 2351: 93-104, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34382185

RESUMO

MNase-Seq is a genome-wide procedure that allows mapping of DNA associated to nucleosomes following micrococcal nuclease digestion. It is a rapid and robust technology useful for the analysis of chromatin properties genome-wide at the resolution of mono-nucleosomes. Here, we describe how to produce high-resolution nucleosome maps of cells grown in suspension or adherent mammalian cells. After only three steps: nuclei or cell preparation, native MNase digestion and DNA purification, libraries for high-throughput sequencing can be prepared. Genome-wide nucleosome maps allow analyzing chromatin opening at promoters or enhancers, nucleosome displacement, or labile nucleosome occupancy depending on the digestion condition used. As presented, MNase-Seq is a versatile tool for investigating chromatin dynamics, regulation, and to define open chromatin regions of regulatory elements in mammalian genomes.


Assuntos
Elementos Facilitadores Genéticos , Estudo de Associação Genômica Ampla/métodos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Nucleossomos/metabolismo , Regiões Promotoras Genéticas , Animais , Células Cultivadas , Cromatina/genética , Cromatina/metabolismo , Mapeamento Cromossômico , Biologia Computacional/métodos , Biblioteca Gênica
9.
Methods Mol Biol ; 2351: 105-121, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34382186

RESUMO

Assay for Transposase-Accessible Chromatin using sequencing (ATAC-Seq) is a method to investigate the accessibility of chromatin in a genome-wide fashion. In this chapter, we provide a brief history of the chromatin accessibility field followed by a detailed protocol to perform ATAC-Seq assay.


Assuntos
Montagem e Desmontagem da Cromatina , Cromatina/genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Biologia Computacional/métodos , Elementos de DNA Transponíveis , Análise de Dados , Regulação da Expressão Gênica , Biblioteca Gênica , Estudo de Associação Genômica Ampla , Humanos , Nucleossomos/metabolismo , Controle de Qualidade , Análise de Sequência de DNA , Transposases/metabolismo
10.
Methods Mol Biol ; 2351: 165-179, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34382189

RESUMO

Targeted chromatin capture (T2C) is a 3C-based method and is used to study the 3D chromatin organization, interactomes and structural changes associated with gene regulation, progression through the cell cycle, and cell survival and development. Low input targeted chromatin capture (low-T2C) is an optimized version of the T2C protocol for low numbers of cells. Here, we describe the protocol for low-T2C, including all experimental steps and bioinformatics tools in detail.


Assuntos
Montagem e Desmontagem da Cromatina , Cromatina/genética , Biologia Computacional/métodos , Cromatina/química , Cromatina/metabolismo , Mapeamento Cromossômico , Regulação da Expressão Gênica , Biblioteca Gênica , Genômica/métodos , Reprodutibilidade dos Testes
11.
Methods Mol Biol ; 2351: 211-227, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34382192

RESUMO

The open chromatin enrichment and network Hi-C (OCEAN-C) was developed not only for identifying large-scale chromatin structures, including topologically associated domains (TADs) and A/B compartments, but also for globally mapping hubs of open chromatin interactions (HOCIs) and their interaction networks independent of antibody and bait-sequences.


Assuntos
Montagem e Desmontagem da Cromatina , Cromatina/genética , Biologia Computacional/métodos , Sítios de Ligação , Cromatina/metabolismo , Regulação da Expressão Gênica , Biblioteca Gênica , Sequenciamento de Nucleotídeos em Larga Escala , Ligação Proteica , Controle de Qualidade , Software , Transcrição Genética , Navegador
12.
Methods Mol Biol ; 2351: 353-368, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34382200

RESUMO

DNA methylation can regulate gene expression by modulating chromatin accessibility and transcription factor binding on promoter and enhancer regions. Whole-genome bisulfite sequencing (WGBS) represents the most informative and comprehensive analysis to profile the DNA methylation status of all the cytosines at single-base resolution. However, most of the available protocols recommend an amount of input DNA (50 ng-5µg) that makes the WGBS unsuitable for limited samples and cell populations. In this chapter, we provide complete protocol to perform WGBS libraries from very low-input DNA. This protocol is recommended for the analysis of the whole-genome DNA methylation pattern in rare cell populations, like a defined stem cell population isolated from animal models or human samples.


Assuntos
Metilação de DNA , Epigênese Genética , Epigenômica/métodos , Sequenciamento Completo do Genoma/métodos , Biologia Computacional/métodos , Ilhas de CpG , Elementos Facilitadores Genéticos , Biblioteca Gênica , Técnicas de Amplificação de Ácido Nucleico , Regiões Promotoras Genéticas , Software
13.
Int J Mol Sci ; 22(16)2021 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-34445358

RESUMO

The human dopamine receptors D2S and D3 belong to the group of G protein-coupled receptors (GPCRs) and are important drug targets. Structural analyses and development of new receptor subtype specific drugs have been impeded by low expression yields or receptor instability. Fusing the T4 lysozyme into the intracellular loop 3 improves crystallization but complicates conformational studies. To circumvent these problems, we expressed the human D2S and D3 receptors in Escherichia coli using different N- and C-terminal fusion proteins and thermostabilizing mutations. We optimized expression times and used radioligand binding assays with whole cells and membrane homogenates to evaluate KD-values and the number of receptors in the cell membrane. We show that the presence but not the type of a C-terminal fusion protein is important. Bacteria expressing receptors capable of ligand binding can be selected using FACS analysis and a fluorescently labeled ligand. Improved receptor variants can thus be generated using error-prone PCR. Subsequent analysis of clones showed the distribution of mutations over the whole gene. Repeated cycles of PCR and FACS can be applied for selecting highly expressing receptor variants with high affinity ligand binding, which in the future can be used for analytical studies.


Assuntos
Escherichia coli/genética , Engenharia de Proteínas/métodos , Receptores Dopaminérgicos/genética , Calibragem , Membrana Celular/metabolismo , Clonagem Molecular/métodos , Escherichia coli/metabolismo , Biblioteca Gênica , Humanos , Mutação , Organismos Geneticamente Modificados , Engenharia de Proteínas/normas , Receptores Dopaminérgicos/metabolismo , Receptores de Dopamina D2/genética , Receptores de Dopamina D2/metabolismo , Receptores de Dopamina D3/genética , Receptores de Dopamina D3/metabolismo , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Transformação Bacteriana , Transgenes
14.
Mol Biol (Mosk) ; 55(4): 562-577, 2021.
Artigo em Russo | MEDLINE | ID: mdl-34432774

RESUMO

The application of array-based oligonucleotides in biological studies is described. These oligonucleotides are mainly used to design large libraries of various nucleotide sequences, which are applied to study protein-nucleic acid interactions, splicing, transcription, translation, and other regulatory processes in mammalian, yeast, and bacterial systems. The application of gene libraries generated by array-based nucleotides along with advanced methods of the combination of DNA duplexes will make it possible to obtain complex genetic designs for synthetic biology.


Assuntos
DNA , Oligonucleotídeos , Animais , Sequência de Bases , Biblioteca Gênica , Oligonucleotídeos/genética
15.
BMC Res Notes ; 14(1): 326, 2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-34433501

RESUMO

OBJECTIVES: Haemaphysalis longicornis is the most important tick species in Japan and has a wide range of vector capacity. Due to its veterinary and medical importance, this tick species has been used as a model for tick/vector biological studies. To identify the key molecules associated with physiological processes during blood feeding and embryogenesis, full-length cDNA libraries were constructed using the fat body, hemocytes-containing hemolymph, midgut, ovary and salivary glands of fed females and embryos of the laboratory colony of parthenogenetic H. longicornis. The sequences of cDNA from the salivary glands had been already released. However, the related information is still poor, and the other expressed sequence tags have not yet been deposited. DATA DESCRIPTION: A total of 39,113 expressed sequence tags were obtained and deposited at the DNA DataBank of Japan. There were 7745 sequences from embryos, 7385 from the fat body, 8303 from the hemolymph including hemocytes, 7385 from the midgut, and 8295 from the ovary. The data, including expressed sequence tags from the salivary glands was summarized into Microsoft Excel files. Sharing this data resource with the tick research community will be valuable for the identification of novel genes and advance the progress of tick research.


Assuntos
Ixodidae , Sequência de Aminoácidos , Animais , Sequência de Bases , Etiquetas de Sequências Expressas , Feminino , Biblioteca Gênica , Ixodidae/genética
16.
Nat Commun ; 12(1): 4902, 2021 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-34385461

RESUMO

Efficient and precise base editors (BEs) for C-to-G transversion are highly desirable. However, the sequence context affecting editing outcome largely remains unclear. Here we report engineered C-to-G BEs of high efficiency and fidelity, with the sequence context predictable via machine-learning methods. By changing the species origin and relative position of uracil-DNA glycosylase and deaminase, together with codon optimization, we obtain optimized C-to-G BEs (OPTI-CGBEs) for efficient C-to-G transversion. The motif preference of OPTI-CGBEs for editing 100 endogenous sites is determined in HEK293T cells. Using a sgRNA library comprising 41,388 sequences, we develop a deep-learning model that accurately predicts the OPTI-CGBE editing outcome for targeted sites with specific sequence context. These OPTI-CGBEs are further shown to be capable of efficient base editing in mouse embryos for generating Tyr-edited offspring. Thus, these engineered CGBEs are useful for efficient and precise base editing, with outcome predictable based on sequence context of targeted sites.


Assuntos
Sistemas CRISPR-Cas , Citidina Desaminase/metabolismo , Edição de Genes/métodos , Aprendizado de Máquina , Uracila-DNA Glicosidase/metabolismo , Animais , Sequência de Bases , Sítios de Ligação/genética , Caenorhabditis elegans/genética , Códon/genética , Citidina Desaminase/genética , Escherichia coli/genética , Feminino , Biblioteca Gênica , Células HEK293 , Humanos , Camundongos , Reprodutibilidade dos Testes , Uracila-DNA Glicosidase/genética
17.
Anal Chem ; 93(29): 10243-10250, 2021 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-34270210

RESUMO

In-source fragmentation (ISF) is a naturally occurring phenomenon during electrospray ionization (ESI) in liquid chromatography-mass spectrometry (LC-MS) analysis. ISF leads to false metabolite annotation in untargeted metabolomics, prompting misinterpretation of the underlying biological mechanisms. Conventional metabolomic data cleaning mainly focuses on the annotation of adducts and isotopes, and the recognition of ISF features is mainly based on common neutral losses and the LC coelution pattern. In this work, we recognized three increasingly important patterns of ISF features, including (1) coeluting with their precursor ions, (2) being in the tandem MS (MS2) spectra of their precursor ions, and (3) sharing similar MS2 fragmentation patterns with their precursor ions. Based on these patterns, we developed an R package, ISFrag, to comprehensively recognize all possible ISF features from LC-MS data generated from full-scan, data-dependent acquisition, and data-independent acquisition modes without the assistance of common neutral loss information or MS2 spectral library. Tested using metabolite standards, we achieved a 100% correct recognition of level 1 ISF features and over 80% correct recognition for level 2 ISF features. Further application of ISFrag on untargeted metabolomics data allows us to identify ISF features that can potentially cause false metabolite annotation at an omics-scale. With the help of ISFrag, we performed a systematic investigation of how ISF features are influenced by different MS parameters, including capillary voltage, end plate offset, ion energy, and "collision energy". Our results show that while increasing energies can increase the number of real metabolic features and ISF features, the percentage of ISF features might not necessarily increase. Finally, using ISFrag, we created an ISF pathway to visualize the relationships between multiple ISF features that belong to the same precursor ion. ISFrag is freely available on GitHub (https://github.com/HuanLab/ISFrag).


Assuntos
Metabolômica , Espectrometria de Massas em Tandem , Cromatografia Líquida , Biblioteca Gênica , Íons
18.
Methods Mol Biol ; 2312: 59-72, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34228284

RESUMO

Antibodies have been attracting attention as therapeutic tools owing to their high affinity and specificity. To develop potent antibodies, affinity maturation, epitope regulation, and using target antigens in native form are pivotal requirements. Here we describe a method to conduct epitope-directed affinity maturation of antibodies using engineered mammalian cells. This method utilizes protein chimeras that transduce cell death signaling in response to antibody binding. As the competition of antibody binding inhibits the cell death signaling, only affinity-matured antibodies retaining the same epitope as an original one can be selected using cell survival as readout.


Assuntos
Engenharia Celular , Epitopos , Anticorpos de Cadeia Única/genética , Afinidade de Anticorpos , Morte Celular , Células Cultivadas , Biblioteca Gênica , Vetores Genéticos , Transdução de Sinais , Anticorpos de Cadeia Única/metabolismo , Transdução Genética
19.
Analyst ; 146(15): 4803-4810, 2021 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-34241602

RESUMO

Pattern recognition, also called "array sensing," is a recognition strategy with a wide and expandable analysis range, based on high-throughput analysis data. In this work, we constructed a sensor array for the identification of targets including bacterial pathogens and proteins by using FAM-labeled DNA probes and 2D nanosheet materials. We designed an ordered and extendible DNA library for the collection of recognition probes. Unlike traditional DNA probes with random and massive sequences, our DNA library was constructed following a 5-digit binary number (00000-11111, 0 = CCC, and 1 = TTT), and especially, 8 special symmetry sequences were chosen from the library. Two different nanosheet materials were used as the quencher. When targets were added, the interaction between DNA and the nanosheets was competitively affected, and as a result, the fluorescence signal changed accordingly. Finally, by using our fluorescent sensor array, 17 bacteria and 8 proteins were precisely recognized. We believe that our work has provided a simple and valuable strategy for the improvement of the recognition range and discrimination precision for the development of pattern recognition.


Assuntos
Nanoestruturas , DNA/genética , Sondas de DNA/genética , Corantes Fluorescentes , Biblioteca Gênica , Espectrometria de Fluorescência
20.
Am J Hum Genet ; 108(7): 1283-1300, 2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-34214447

RESUMO

Most rare clinical missense variants cannot currently be classified as pathogenic or benign. Deficiency in human 5,10-methylenetetrahydrofolate reductase (MTHFR), the most common inherited disorder of folate metabolism, is caused primarily by rare missense variants. Further complicating variant interpretation, variant impacts often depend on environment. An important example of this phenomenon is the MTHFR variant p.Ala222Val (c.665C>T), which is carried by half of all humans and has a phenotypic impact that depends on dietary folate. Here we describe the results of 98,336 variant functional-impact assays, covering nearly all possible MTHFR amino acid substitutions in four folinate environments, each in the presence and absence of p.Ala222Val. The resulting atlas of MTHFR variant effects reveals many complex dependencies on both folinate and p.Ala222Val. MTHFR atlas scores can distinguish pathogenic from benign variants and, among individuals with severe MTHFR deficiency, correlate with age of disease onset. Providing a powerful tool for understanding structure-function relationships, the atlas suggests a role for a disordered loop in retaining cofactor at the active site and identifies variants that enable escape of inhibition by S-adenosylmethionine. Thus, a model based on eight MTHFR variant effect maps illustrates how shifting landscapes of environment- and genetic-background-dependent missense variation can inform our clinical, structural, and functional understanding of MTHFR deficiency.


Assuntos
Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Mutação de Sentido Incorreto , Substituição de Aminoácidos , Análise Mutacional de DNA , Diploide , Biblioteca Gênica , Genótipo , Humanos , Metilenotetra-Hidrofolato Redutase (NADPH2)/deficiência , Metilenotetra-Hidrofolato Redutase (NADPH2)/fisiologia , Saccharomyces cerevisiae/genética
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