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The brain is highly sensitive to damage caused by infection and inflammation1,2. Herpes simplex virus 1 (HSV-1) is a neurotropic virus and the cause of herpes simplex encephalitis3. It is unknown whether neuron-specific antiviral factors control virus replication to prevent infection and excessive inflammatory responses, hence protecting the brain. Here we identify TMEFF1 as an HSV-1 restriction factor using genome-wide CRISPR screening. TMEFF1 is expressed specifically in neurons of the central nervous system and is not regulated by type I interferon, the best-known innate antiviral system controlling virus infections. Depletion of TMEFF1 in stem-cell-derived human neurons led to elevated viral replication and neuronal death following HSV-1 infection. TMEFF1 blocked the HSV-1 replication cycle at the level of viral entry through interactions with nectin-1 and non-muscle myosin heavy chains IIA and IIB, which are core proteins in virus-cell binding and virus-cell fusion, respectively4-6. Notably, Tmeff1-/- mice exhibited increased susceptibility to HSV-1 infection in the brain but not in the periphery. Within the brain, elevated viral load was observed specifically in neurons. Our study identifies TMEFF1 as a neuron-specific restriction factor essential for prevention of HSV-1 replication in the central nervous system.
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Fatores de Restrição Antivirais , Encéfalo , Herpes Simples , Herpesvirus Humano 1 , Proteínas de Membrana , Neurônios , Internalização do Vírus , Replicação Viral , Animais , Feminino , Humanos , Masculino , Camundongos , Fatores de Restrição Antivirais/metabolismo , Encéfalo/citologia , Encéfalo/metabolismo , Encéfalo/patologia , Encéfalo/virologia , Morte Celular , Sistemas CRISPR-Cas/genética , Herpes Simples/imunologia , Herpes Simples/metabolismo , Herpes Simples/virologia , Herpesvirus Humano 1/crescimento & desenvolvimento , Herpesvirus Humano 1/imunologia , Herpesvirus Humano 1/fisiologia , Proteínas de Membrana/metabolismo , Proteínas de Membrana/deficiência , Proteínas de Membrana/genética , Neurônios/virologia , Neurônios/metabolismo , Carga Viral , Nectinas/metabolismo , Miosina não Muscular Tipo IIA/metabolismo , Miosina não Muscular Tipo IIB/metabolismo , Interferon Tipo I , Doenças Neuroinflamatórias/imunologia , Doenças Neuroinflamatórias/metabolismo , Doenças Neuroinflamatórias/patologia , Doenças Neuroinflamatórias/prevenção & controle , Doenças Neuroinflamatórias/virologiaRESUMO
Implementation of therapeutic in vivo gene editing using CRISPR/Cas relies on potent delivery of gene editing tools. Administration of ribonucleoprotein (RNP) complexes consisting of Cas protein and single guide RNA (sgRNA) offers short-lived editing activity and safety advantages over conventional viral and non-viral gene and RNA delivery approaches. By engineering lentivirus-derived nanoparticles (LVNPs) to facilitate RNP delivery, we demonstrate effective administration of SpCas9 as well as SpCas9-derived base and prime editors (BE/PE) leading to gene editing in recipient cells. Unique Gag/GagPol protein fusion strategies facilitate RNP packaging in LVNPs, and refinement of LVNP stoichiometry supports optimized LVNP yield and incorporation of therapeutic payload. We demonstrate near instantaneous target DNA cleavage and complete RNP turnover within 4 days. As a result, LVNPs provide high on-target DNA cleavage and lower levels of off-target cleavage activity compared to standard RNP nucleofection in cultured cells. LVNPs accommodate BE/sgRNA and PE/epegRNA RNPs leading to base editing with reduced bystander editing and prime editing without detectable indel formation. Notably, in the mouse eye, we provide the first proof-of-concept for LVNP-directed in vivo gene disruption. Our findings establish LVNPs as promising vehicles for delivery of RNPs facilitating donor-free base and prime editing without formation of double-stranded DNA breaks.
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INTRODUCTION: In epithelial cancers, truncated O-glycans, such as the Thomson-nouveau antigen (Tn) and its sialylated form (STn), are upregulated on the cell surface and associated with poor prognosis and immunological escape. Recent studies have shown that these carbohydrate epitopes facilitate cancer development and can be targeted therapeutically; however, the mechanism underpinning their expression remains unclear. METHODS: To identify genes directly influencing the expression of cancer-associated O-glycans, we conducted an unbiased, positive-selection, whole-genome CRISPR knockout-screen using monoclonal antibodies against Tn and STn. RESULTS AND CONCLUSIONS: We show that knockout of the Zn2+-transporter SLC39A9 (ZIP9), alongside the well-described targets C1GALT1 (C1GalT1) and its molecular chaperone, C1GALT1C1 (COSMC), results in surface-expression of cancer-associated O-glycans. No other gene perturbations were found to reliably induce O-glycan truncation. We furthermore show that ZIP9 knockout affects N-linked glycosylation, resulting in upregulation of oligo-mannose, hybrid-type, and α2,6-sialylated structures as well as downregulation of tri- and tetra-antennary structures. Finally, we demonstrate that accumulation of Zn2+ in the secretory pathway coincides with cell-surface presentation of truncated O-glycans in cancer tissue, and that over-expression of COSMC mitigates such changes. Collectively, the findings show that dysregulation of ZIP9 and Zn2+ induces cancer-like glycosylation on the cell surface by affecting the glycosylation machinery.
Assuntos
Antígenos Glicosídicos Associados a Tumores , Neoplasias , Humanos , Glicosilação , Antígenos Glicosídicos Associados a Tumores/genética , Antígenos Glicosídicos Associados a Tumores/metabolismo , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , Neoplasias/genética , Neoplasias/metabolismo , Chaperonas Moleculares/genética , Polissacarídeos/genética , Polissacarídeos/metabolismo , ZincoRESUMO
The frontline therapy R-CHOP for patients with diffuse large B-cell lymphoma (DLBCL) has remained unchanged for two decades despite numerous Phase III clinical trials investigating new alternatives. Multiple large studies have uncovered genetic subtypes of DLBCL enabling a targeted approach. To further pave the way for precision oncology, we perform genome-wide CRISPR screening to uncover the cellular response to one of the components of R-CHOP, vincristine, in the DLBCL cell line SU-DHL-5. We discover important pathways and subnetworks using gene-set enrichment analysis and protein-protein interaction networks and identify genes related to mitotic spindle organization that are essential during vincristine treatment. The inhibition of KIF18A, a mediator of chromosome alignment, using the small molecule inhibitor BTB-1 causes complete cell death in a synergistic manner when administered together with vincristine. We also identify the genes KIF18B and USP28 of which CRISPR/Cas9-directed knockout induces vincristine resistance across two DLBCL cell lines. Mechanistic studies show that lack of KIF18B or USP28 counteracts a vincristine-induced p53 response suggesting that resistance to vincristine has origin in the mitotic surveillance pathway (USP28-53BP1-p53). Collectively, our CRISPR screening data uncover potential drug targets and mechanisms behind vincristine resistance, which may support the development of future drug regimens.
Assuntos
Linfoma Difuso de Grandes Células B , Proteína Supressora de Tumor p53 , Humanos , Vincristina/farmacologia , Vincristina/uso terapêutico , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Medicina de Precisão , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Linfoma Difuso de Grandes Células B/genética , Linfoma Difuso de Grandes Células B/patologia , Rituximab/uso terapêutico , Pontos de Checagem do Ciclo Celular , Apoptose , Ciclofosfamida/uso terapêutico , Prednisona/uso terapêutico , Doxorrubicina/farmacologia , Doxorrubicina/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Ubiquitina Tiolesterase , Cinesinas/genéticaRESUMO
Prime editing (PE) is a novel CRISPR-derived genome editing technique facilitating precision editing without double-stranded DNA breaks. PE, mediated by a Cas9-reverse transcriptase fusion protein, is based on dual-functioning prime editing guide RNAs (pegRNAs), serving both as guide molecules and as templates carrying the desired edits. Due to such diverse functions, manual pegRNA design is a subject to error and not suited for large-scale setups. Here, we present pegIT, a user-friendly web tool for rapid pegRNA design for numerous user-defined edits, including large-scale setups. pegIT is freely available at https://pegit.giehmlab.dk.
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Edição de Genes/métodos , Software , Proteína 9 Associada à CRISPR/genética , Internet , RNA/química , DNA Polimerase Dirigida por RNA/genética , Proteínas Recombinantes de FusãoRESUMO
The Gram-negative bacterium Yersinia ruckeri is the causative agent for enteric red mouth disease in salmonids. The genome of Y. ruckeri YRB contains a biosynthetic gene cluster encoding the biosynthesis of catechol siderophores that are diastereomeric with the known vanchrobactin class of siderophores, (DHBDArgLSer)(1-3). Ruckerbactin (1), produced by Y. ruckeri YRB, was found to be the linear tris-l-serine ester composed of l-arginine and 2,3-dihydroxybenzoic acid, (DHBLArgLSer)3. The biscatechol, (DHBLArgLSer)2 (2), and monocatechol, DHBLArgLSer (3), compounds were also isolated and characterized. The macrolactone of ruckerbactin was not detected. The presence of LArg in ruckerbactin makes it the diastereomer of trivanchrobactin with DArg. The electronic circular dichroism spectra of Fe(III)-ruckerbactin and Fe(III)-trivanchrobactin reveal the opposite enantiomeric configurations at the Fe(III) sites. Fe(III)-ruckerbactin adopts the Δ configuration, and Fe(III)-trivanchrobactin adopts the Λ configuration. Y. ruckeri YRB was also found to produce the antimicrobial agent holomycin (4).
Assuntos
Peptídeos , Vibrio , Yersinia ruckeri , Dicroísmo Circular , Peptídeos/metabolismo , Sideróforos , Análise Espectral/métodos , Estereoisomerismo , Vibrio/metabolismo , Yersinia ruckeri/metabolismoRESUMO
A prognostic 3-miRNA classifier for early-stage mycosis fungoides has been developed recently, with miR-106b providing the strongest prognostic power. The aim of this study was to investigate the molecular function of miR-106b in mycosis fungoides disease progression. The cellular localization of miR-106b in mycosis fungoides skin biopsies was determined by in situ hybridization. The regulatory role of miR-106b was assessed by transient miR-106b inhibitor/mimic transfection of 2 mycosis fungoides derived cell lines, followed by quantitative real-time PCR (RT-qPCR), western blotting and a proliferation assay. MiR-106b was found to be expressed by dermal T-lymphocytes in mycosis fungoides skin lesions, and miR-106b expression increased with advancing mycosis fungoides stage. Transfection of miR-106b in 2 mycosis fungoides derived cell lines showed that miR-106b represses the tumour suppressors cyclin-dependent kinase inhibitor 1 (p21) and thioredoxin-interacting protein (TXNIP) and promotes mycosis fungoides tumour cell proliferation. In conclusion, these results substantiate that miR-106b has both a functional and prognostic role in progression of mycosis fungoides.
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MicroRNAs , Micose Fungoide , Neoplasias Cutâneas , Proteínas de Transporte , Proliferação de Células , Humanos , MicroRNAs/genética , Micose Fungoide/genética , Prognóstico , Neoplasias Cutâneas/genéticaRESUMO
Polymers are promising candidates as solid-state electrolytes due to their performance and processability, but fillers play a critical role in adjusting the polymer network structure and electrochemical, thermal, and mechanical properties. Most fillers studied so far are anisotropic, limiting the possibility of homogeneous ion transport. Here, applying metal-organic framework (MOF) glass as an isotropic functional filler, solid-state polyethylene oxide (PEO) electrolytes are prepared. Calorimetric and diffusion kinetics tests show that the MOF glass addition reduces the glass transition temperature of the polymer phase, improving the mobility of the polymer chains, and thereby facilitating lithium (Li) ion transport. By also incorporating the lithium salt and ionic liquid (IL), Li-Li symmetric cell tests of the PEO-lithium salt-MOF glass-IL electrolyte reveal low overpotential, indicating low interfacial impedance. Simulations show that the isotropic structure of the MOF glass facilitates the wettability of the IL by enhancing interfacial interactions, leading to a less confined IL structure that promotes Li-ion mobility. Finally, the obtained electrolyte is used to construct Li-lithium iron phosphate full batteries that feature high cycle stability and rate capability. This work therefore demonstrates how an isotropic functional filler can be used to enhance the electrochemical performance of solid-state polymer electrolytes.
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The vast majority of bacteria require iron to grow. A significant iron acquisition strategy is the production of siderophores, which are secondary microbial metabolites synthesized to sequester iron(III). Siderophore structures encompass a variety of forms, of which highly modified peptidic siderophores are of interest herein. State-of-the-art genome mining tools, such as antiSMASH (antibiotics & Secondary Metabolite Analysis SHell), hold the potential to predict and discover new peptidic siderophores, including a combinatoric suite of triscatechol siderophores framed on a triserine-ester backbone of the general class, (DHB-l/d CAA-l Ser)3 (CAA, cationic amino acid). Siderophores with l/d Arg, l/d Lys and l Orn, but not d Orn, were predicted in bacterial genomes. Fortuitously the d Orn siderophore was identified, yet its lack of prediction highlights the limitation of current genome mining tools. The full combinatoric suite of these siderophores, which form chiral iron(III) complexes, reveals stereospecific coordination chemistry encoded in microbial genomes. The chirality embedded in this suite of Fe(III)-siderophores raises the question of whether the relevant siderophore-mediated iron acquisition pathways are stereospecific and selective for ferric siderophore complexes of a defined configuration.
Assuntos
Compostos Férricos , Sideróforos , Sideróforos/genética , Compostos Férricos/metabolismo , Ferro/metabolismo , Bactérias/metabolismo , Genoma Bacteriano , Peptídeos/genética , Peptídeos/metabolismoRESUMO
Locus-directed DNA cleavage induced by the CRISPR-Cas9 system triggers DNA repair mechanisms allowing gene repair or targeted insertion of foreign DNA. For gene insertion to be successful, availability of a homologous donor template needs to be timed with cleavage of the DNA by the Cas9 endonuclease guided by a target-specific single guide RNA (sgRNA). We present a novel approach for targeted gene insertion based on a single integrase-defective lentiviral vector (IDLV) carrying a Cas9 off switch. Gene insertion using this approach benefits from transposon-based stable Cas9 expression, which is switched off by excision-only transposase protein co-delivered in IDLV particles carrying a combined sgRNA/donor vector. This one-vector approach supports potent (up to >80%) knockin of a full-length EGFP gene sequence. This traceless cell engineering method benefits from high stable levels of Cas9, timed intracellular availability of the molecular tools, and a built-in feature to turn off Cas9 expression after DNA cleavage. The simple technique is based on transduction with a single IDLV, which holds the capacity to transfer larger donor templates, allowing robust gene knockin or tagging of genes in a single step.
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Antibody-based immunotherapy targeting the interaction between programmed cell death 1 (PD-1) and its ligand PD-L1 has shown impressive clinical outcomes in various cancer types, including nonsmall cell lung cancer (NSCLC). However, regulatory mechanisms in this immune checkpoint pathway still needs clarification. PD-L2 is structurally homologous to PD-L1 and is a second PD-1 ligand. Alternative mRNA splicing from the CD274 and PDCD1LG2 genes holds the potential to generate PD-L1 and PD-L2 isoforms, respectively, with novel functionality in regulation of the PD-1 immune checkpoint pathway. Here, we describe alternative splicing in NSCLC cells potentially generating eight different PD-L2 isoforms from the PDCD1LG2 gene. Extension of exon 6 by four nucleotides is the most prominent alternative splicing event and results in PD-L2 isoform V with a cytoplasmic domain containing a 10 amino acid extension. On average 13% of the PDCD1LG2 transcripts in NSCLC cell lines and 22% of the transcripts in NSCLC tumor biopsies encode PD-L2 isoform V. PD-L2 isoform V localizes to the cell surface membrane but less efficiently than the canonical PD-L2 isoform I. The cytoplasmic domains of PD-1 ligands can affect immune checkpoint pathways by conferring membrane localization and protein stability and thereby represent alternative targets for immunotherapy. In addition, cytoplasmic domains are involved in intracellular signalling cascades in cancer cells. The presented observations of different cytoplasmic domains of PD-L2 will be important in the future delineation of the PD-1 immune checkpoint pathway.
Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Processamento Alternativo , Aminoácidos/genética , Aminoácidos/metabolismo , Aminoácidos/uso terapêutico , Antígeno B7-H1/metabolismo , Carcinoma Pulmonar de Células não Pequenas/genética , Citoplasma/metabolismo , Humanos , Ligantes , Neoplasias Pulmonares/tratamento farmacológico , Nucleotídeos/metabolismo , Nucleotídeos/uso terapêutico , Proteína 2 Ligante de Morte Celular Programada 1/genética , Proteína 2 Ligante de Morte Celular Programada 1/metabolismo , Receptor de Morte Celular Programada 1/metabolismo , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , RNA MensageiroRESUMO
DNA repair gene mutations are frequent in castration-resistant prostate cancer (CRPC), suggesting eligibility for poly(ADP-ribose) polymerase inhibitor (PARPi) treatment. However, therapy resistance is a major clinical challenge and genes contributing to PARPi resistance are poorly understood. Using a genome-wide CRISPR-Cas9 knockout screen, this study aimed at identifying genes involved in PARPi resistance in CRPC. Based on the screen, we identified PARP1, and six novel candidates associated with olaparib resistance upon knockout. For validation, we generated multiple knockout populations/clones per gene in C4 and/or LNCaP CRPC cells, which confirmed that loss of PARP1, ARH3, YWHAE, or UBR5 caused olaparib resistance. PARP1 or ARH3 knockout caused cross-resistance to other PARPis (veliparib and niraparib). Furthermore, PARP1 or ARH3 knockout led to reduced autophagy, while pharmacological induction of autophagy partially reverted their PARPi resistant phenotype. Tumor RNA sequencing of 126 prostate cancer patients identified low ARH3 expression as an independent predictor of recurrence. Our results advance the understanding of PARPi response by identifying four novel genes that contribute to PARPi sensitivity in CRPC and suggest a new model of PARPi resistance through decreased autophagy.
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Antineoplásicos , Neoplasias de Próstata Resistentes à Castração , Antineoplásicos/farmacologia , Sistemas CRISPR-Cas , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos/genética , Humanos , Masculino , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Inibidores de Poli(ADP-Ribose) Polimerases/uso terapêutico , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Neoplasias de Próstata Resistentes à Castração/genética , Neoplasias de Próstata Resistentes à Castração/patologiaRESUMO
Prime editing is a novel genome editing technology that allows a wide range of tailored genomic alterations. Prime editing does not involve homologous recombination, but suffers from low efficacy. Here, we demonstrate piggyPrime, a transfected single-vector system based on piggyBac DNA transposition for genomic integration of all prime editing components in human cells allowing easy and effective transgenesis with prime editing efficacies up to 100% in cell lines.
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The innate immune system represents a balanced first line of defense against infection. Type I interferons (IFNs) are key regulators of the response to viral infections with an essential early wave of IFN-ß expression, which is conditional, time-restricted, and stochastic in its nature. The possibility to precisely monitor individual cells with active IFNB1 transcription during innate signaling requires a robust reporter system that mimics the endogenous IFN-ß signal. Here, we present a reporter system based on expression of a destabilized version of eGFP (d2eGFP) from a stably integrated reporter cassette containing the IFNB1 promoter and 3'-untranslated region, enabling both spatial and temporal detection of regulated IFNB1 expression. Specifically, this reporter permits detection, quantification, and isolation of cells actively producing d2eGFP in a manner that fully mimics IFN-ß production allowing tracking of IFNB1 gene activation and repression in monocytic cells and keratinocytes. Using induced d2eGFP expression as a readout for activated immune signaling at the single-cell level, we demonstrate the application of the reporter for FACS-based selection of cells with genotypes supporting cGAS-STING signaling. Our studies provide a novel approach for monitoring on/off-switching of innate immune signaling and form the basis for investigating genotypes affecting immune regulation at the single-cell level.
Assuntos
Interferon Tipo I , Interferon beta , Imunidade Inata/genética , Interferon Tipo I/genética , Interferon beta/metabolismo , Regiões Promotoras Genéticas , Transdução de SinaisRESUMO
Here, we report the sequencing, assembly, and annotation of the genome of the rare actinobacterium Kutzneria sp. strain CA-103260. The genome of CA-103260 was sequenced using PacBio and Illumina technologies and it consists of a circular 11,609,901-bp chromosome.
RESUMO
Actinobacteria have been a rich source of novel, structurally complex natural products for many decades. Although the largest genus is Streptomyces, from which the majority of antibiotics in current and past clinical use were originally isolated, other less common genera also have the potential to produce a wealth of novel secondary metabolites. One example is the Kutzneria genus, which currently contains only five reported species. One of these species is Kutzneria albida DSM 43870T, which has 46 predicted biosynthetic gene clusters and is known to produce the macrolide antibiotic aculeximycin. Here, we report the isolation and structural characterization of two novel 30-membered glycosylated macrolides, epemicins A and B, that are structurally related to aculeximycin, from a rare Kutzneria sp. The absolute configuration for all chiral centers in the two compounds is proposed based on extensive 1D and 2D NMR studies and bioinformatics analysis of the gene cluster. Through heterologous expression and genetic inactivation, we have confirmed the link between the biosynthetic gene cluster and the new molecules. These findings show the potential of rare Actinobacteria to produce new, structurally diverse metabolites. Furthermore, the gene inactivation represents the first published report to genetically manipulate a representative of the Kutzneria genus.
Assuntos
Actinobacteria/química , Antibacterianos/farmacologia , Macrolídeos/farmacologia , Actinobacteria/genética , Actinobacteria/metabolismo , Antibacterianos/biossíntese , Antibacterianos/química , Antibacterianos/isolamento & purificação , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Descoberta de Drogas , Macrolídeos/química , Macrolídeos/isolamento & purificação , Macrolídeos/metabolismo , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Família Multigênica , Policetídeo Sintases/química , Policetídeo Sintases/genética , Policetídeo Sintases/metabolismo , Domínios Proteicos , EstereoisomerismoRESUMO
Diffuse large B-cell lymphoma (DLBCL) is characterized by extensive genetic heterogeneity, and this results in unpredictable responses to the current treatment, R-CHOP, which consists of a cancer drug combination supplemented with the humanized CD20-targeting monoclonal antibody rituximab. Despite improvements in the patient response rate through rituximab addition to the treatment plan, up to 40% of DLBCL patients end in a relapsed or refractory state due to inherent or acquired resistance to the regimen. Here, we employ a lentiviral genome-wide clustered regularly interspaced short palindromic repeats library screening approach to identify genes involved in facilitating the rituximab response in cancerous B cells. Along with the CD20-encoding MS4A1 gene, we identify genes related to B-cell receptor (BCR) signaling as mediators of the intracellular signaling response to rituximab. More specifically, the B-cell linker protein (BLNK) and Bruton's tyrosine kinase (BTK) genes stand out as pivotal genes in facilitating direct rituximab-induced apoptosis through mechanisms that occur alongside complement-dependent cytotoxicity (CDC). Our findings demonstrate that rituximab triggers BCR signaling in a BLNK- and BTK-dependent manner and support the existing notion that intertwined CD20 and BCR signaling pathways in germinal center B-cell-like-subtype DLBCL lead to programmed cell death.
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Tirosina Quinase da Agamaglobulinemia/genética , Apoptose , Sistemas CRISPR-Cas/genética , Centro Germinativo/patologia , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Linfoma Difuso de Grandes Células B/genética , Rituximab/uso terapêutico , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Tirosina Quinase da Agamaglobulinemia/metabolismo , Alelos , Antígenos CD20/metabolismo , Apoptose/efeitos dos fármacos , Apoptose/genética , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos/genética , Centro Germinativo/efeitos dos fármacos , Células HEK293 , Humanos , Mutação/genética , Rituximab/farmacologia , Soro/metabolismoRESUMO
To accelerate the shift to bio-based production and overcome complicated functional implementation of natural and artificial biosynthetic pathways to industry relevant organisms, development of new, versatile, bio-based production platforms is required. Here we present a novel yeast-based platform for biosynthesis of bacterial aromatic polyketides. The platform is based on a synthetic polyketide synthase system enabling a first demonstration of bacterial aromatic polyketide biosynthesis in a eukaryotic host.
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Adaptation of the CRISPR system has enabled scientists to probe the genome and interfere with gene function at an unprecedented scale. Adding to the use of CRISPR for generation of individual gene knockout, which is by now conventional, the CRISPR system enables high-throughput functional screening of the genome. By combining the integrative properties of lentiviral vector delivery with the disruptive nature of the CRISPR system, genome-wide CRISPR libraries provide the power to screen among thousands of genes despite the high complexity of the entire genome and identify a list of genes potentially affecting a certain phenotype. Genome-wide CRISPR screening is an advanced technology compiling numerous practical aspects and a series of molecular biology techniques. In this protocol, we describe all steps toward implementing CRISPR knockout screens in your research; we describe the core procedures and key information as well as some tricks and tips needed to successfully perform a CRISPR screen.
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Sistemas CRISPR-Cas/genética , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas/genética , Técnicas de Inativação de Genes , Estudo de Associação Genômica Ampla , Genômica , Humanos , Fenótipo , Interferência de RNARESUMO
Genetic information transferred by HIV-1-based lentiviral vectors as single-stranded RNA is converted to double-stranded DNA by reverse transcription and subsequently inserted into the genome of recipient cells. Integration into the genome allows stable, long-term expression of genes-of-interest driven by promoter sequences contained within the vector. This technology can be used as a standard method for production of cells stably expressing Cas9 protein and single guide RNA (sgRNA), the key components of the CRISPR genome editing system. Here, we provide a protocol for production and validation of VSV-G-pseudotyped lentiviral vectors for delivery of the CRISPR system and generation of knockout cell lines.