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1.
Cell ; 179(6): 1276-1288.e14, 2019 11 27.
Artículo en Inglés | MEDLINE | ID: mdl-31778654

RESUMEN

Although human genetic studies have implicated many susceptible genes associated with plasma lipid levels, their physiological and molecular functions are not fully characterized. Here we demonstrate that orphan G protein-coupled receptor 146 (GPR146) promotes activity of hepatic sterol regulatory element binding protein 2 (SREBP2) through activation of the extracellular signal-regulated kinase (ERK) signaling pathway, thereby regulating hepatic very low-density lipoprotein (VLDL) secretion, and subsequently circulating low-density lipoprotein cholesterol (LDL-C) and triglycerides (TG) levels. Remarkably, GPR146 deficiency reduces plasma cholesterol levels substantially in both wild-type and LDL receptor (LDLR)-deficient mice. Finally, aortic atherosclerotic lesions are reduced by 90% and 70%, respectively, in male and female LDLR-deficient mice upon GPR146 depletion. Taken together, these findings outline a regulatory role for the GPR146/ERK axis in systemic cholesterol metabolism and suggest that GPR146 inhibition could be an effective strategy to reduce plasma cholesterol levels and atherosclerosis.


Asunto(s)
Aterosclerosis/metabolismo , Hipercolesterolemia/metabolismo , Receptores Acoplados a Proteínas G/deficiencia , Animales , Aterosclerosis/sangre , Secuencia de Bases , Colesterol/sangre , Dependovirus/metabolismo , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Ayuno , Femenino , Hepatocitos/metabolismo , Humanos , Hipercolesterolemia/sangre , Lipoproteínas VLDL/metabolismo , Hígado/metabolismo , Ratones , Ratones Endogámicos C57BL , ARN Interferente Pequeño/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Receptores de LDL/metabolismo , Transducción de Señal , Proteína 2 de Unión a Elementos Reguladores de Esteroles/metabolismo , Triglicéridos/sangre , Regulación hacia Arriba
2.
Mol Cell ; 83(7): 1109-1124.e4, 2023 04 06.
Artículo en Inglés | MEDLINE | ID: mdl-36921607

RESUMEN

The Polycomb-group chromatin modifiers play important roles to repress or switch off gene expression in plants and animals. How the active chromatin state is switched to a Polycomb-repressed state is unclear. In Arabidopsis, prolonged cold induces the switching of the highly active chromatin state at the potent floral repressor FLC to a Polycomb-repressed state, which is epigenetically maintained when temperature rises to confer "cold memory," enabling plants to flower in spring. We report that the cis-acting cold memory element (CME) region at FLC bears bivalent marks of active histone H3K4me3 and repressive H3K27me3 that are read and interpreted by an assembly of bivalent chromatin readers to drive cold-induced switching of the FLC chromatin state. In response to cold, the 47-bp CME and its associated bivalent chromatin feature drive the switching of active chromatin state at a recombinant gene to a Polycomb-repressed domain, conferring cold memory. We reveal a paradigm for environment-induced chromatin-state switching at bivalent loci in plants.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Cromatina/genética , Cromatina/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Proteínas de Dominio MADS/genética , Proteínas de Dominio MADS/metabolismo , Proteínas del Grupo Polycomb/genética , Proteínas del Grupo Polycomb/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Frío , Regulación de la Expresión Génica de las Plantas , Flores/genética , Flores/metabolismo
3.
Immunity ; 53(6): 1315-1330.e9, 2020 12 15.
Artículo en Inglés | MEDLINE | ID: mdl-33275896

RESUMEN

Various vaccine strategies have been proposed in response to the global COVID-19 pandemic, each with unique strategies for eliciting immune responses. Here, we developed nanoparticle vaccines by covalently conjugating the self-assembled 24-mer ferritin to the receptor binding domain (RBD) and/or heptad repeat (HR) subunits of the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) spike (S) protein. Compared to monomer vaccines, nanoparticle vaccines elicited more robust neutralizing antibodies and cellular immune responses. RBD and RBD-HR nanoparticle vaccinated hACE2 transgenic mice vaccinated with RBD and/or RBD-HR nanoparticles exhibited reduced viral load in the lungs after SARS-CoV-2 challenge. RBD-HR nanoparticle vaccines also promoted neutralizing antibodies and cellular immune responses against other coronaviruses. The nanoparticle vaccination of rhesus macaques induced neutralizing antibodies, and T and B cell responses prior to boost immunization; these responses persisted for more than three months. RBD- and HR-based nanoparticles thus present a promising vaccination approach against SARS-CoV-2 and other coronaviruses.


Asunto(s)
Proteínas Bacterianas/inmunología , Vacunas contra la COVID-19/inmunología , COVID-19/inmunología , Ferritinas/inmunología , Helicobacter pylori/metabolismo , Proteínas Recombinantes de Fusión/inmunología , SARS-CoV-2/fisiología , Glicoproteína de la Espiga del Coronavirus/inmunología , Enzima Convertidora de Angiotensina 2/genética , Enzima Convertidora de Angiotensina 2/metabolismo , Animales , Anticuerpos Neutralizantes/metabolismo , Anticuerpos Antivirales/metabolismo , Proteínas Bacterianas/química , Vacunas contra la COVID-19/química , Ferritinas/química , Humanos , Macaca mulatta , Ratones , Ratones Endogámicos BALB C , Nanopartículas/química , Pandemias , Unión Proteica , Glicoproteína de la Espiga del Coronavirus/química , Vacunación
4.
Nature ; 620(7974): 545-551, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37224876

RESUMEN

Doping of perovskite semiconductors1 and passivation of their grain boundaries2 remain challenging but essential for advancing high-efficiency perovskite solar cells. Particularly, it is crucial to build perovskite/indium tin oxide (ITO) Schottky contact based inverted devices without predepositing a layer of hole-transport material3-5. Here we report a dimethylacridine-based molecular doping process used to construct a well-matched p-perovskite/ITO contact, along with all-round passivation of grain boundaries, achieving a certified power conversion efficiency (PCE) of 25.39%. The molecules are shown to be extruded from the precursor solution to the grain boundaries and the bottom of the film surface in the chlorobenzene-quenched crystallization process, which we call a molecule-extrusion process. The core coordination complex between the deprotonated phosphonic acid group of the molecule and lead polyiodide of perovskite is responsible for both mechanical absorption and electronic charge transfer, and leads to p-type doping of the perovskite film. We created an efficient device with a PCE of 25.86% (reverse scan) and that maintained 96.6% of initial PCE after 1,000 h of light soaking.

5.
Nature ; 607(7918): 339-344, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35768511

RESUMEN

Extreme weather conditions associated with climate change affect many aspects of plant and animal life, including the response to infectious diseases. Production of salicylic acid (SA), a central plant defence hormone1-3, is particularly vulnerable to suppression by short periods of hot weather above the normal plant growth temperature range via an unknown mechanism4-7. Here we show that suppression of SA production in Arabidopsis thaliana at 28 °C is independent of PHYTOCHROME B8,9 (phyB) and EARLY FLOWERING 310 (ELF3), which regulate thermo-responsive plant growth and development. Instead, we found that formation of GUANYLATE BINDING PROTEIN-LIKE 3 (GBPL3) defence-activated biomolecular condensates11 (GDACs) was reduced at the higher growth temperature. The altered GDAC formation in vivo is linked to impaired recruitment of GBPL3 and SA-associated Mediator subunits to the promoters of CBP60g and SARD1, which encode master immune transcription factors. Unlike many other SA signalling components, including the SA receptor and biosynthetic genes, optimized CBP60g expression was sufficient to broadly restore SA production, basal immunity and effector-triggered immunity at the elevated growth temperature without significant growth trade-offs. CBP60g family transcription factors are widely conserved in plants12. These results have implications for safeguarding the plant immune system as well as understanding the concept of the plant-pathogen-environment disease triangle and the emergence of new disease epidemics in a warming climate.


Asunto(s)
Aclimatación , Proteínas de Arabidopsis , Arabidopsis , Ambiente , Calentamiento Global , Inmunidad de la Planta , Temperatura , Arabidopsis/crecimiento & desarrollo , Arabidopsis/inmunología , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Proteínas de Unión a Calmodulina/genética , Regulación de la Expresión Génica de las Plantas , Calentamiento Global/estadística & datos numéricos , Interacciones Huésped-Patógeno , Fitocromo B , Enfermedades de las Plantas/genética , Inmunidad de la Planta/genética , Ácido Salicílico/metabolismo , Factores de Transcripción
6.
Mol Cell ; 77(1): 95-107.e5, 2020 01 02.
Artículo en Inglés | MEDLINE | ID: mdl-31628042

RESUMEN

GTP cyclohydrolase I (GTPCH), 6-pyruvoyltetrahydropterin synthase (PTPS), and sepiapterin reductase (SR) are sequentially responsible for de novo synthesis of tetrahydrobiopterin (BH4), a known co-factor for nitric oxide synthase (NOS). The implication of BH4-biosynthesis process in tumorigenesis remains to be investigated. Here, we show that PTPS, which is highly expressed in early-stage colorectal cancer, is phosphorylated at Thr 58 by AMPK under hypoxia; this phosphorylation promotes PTPS binding to LTBP1 and subsequently drives iNOS-mediated LTBP1 S-nitrosylation through proximal-coupling BH4 production within the PTPS/iNOS/LTBP1 complex. In turn, LTBP1 S-nitrosylation results in proteasome-dependent LTBP1 protein degradation, revealing an inverse relationship between PTPS pT58 and LTBP1 stability. Physiologically, the repressive effect of PTPS on LTBP1 leads to impaired transforming growth factor ß (TGF-ß) secretion and thereby maintains tumor cell growth under hypoxia. Our findings illustrate a molecular mechanism underlying the regulation of LTBP1-TGF-ß signaling by the BH4-biosynthesis pathway and highlight the specific requirement of PTPS for tumor growth.


Asunto(s)
Proliferación Celular/fisiología , Neoplasias Colorrectales/metabolismo , Neoplasias Colorrectales/patología , Hipoxia/metabolismo , Proteínas de Unión a TGF-beta Latente/metabolismo , Liasas de Fósforo-Oxígeno/metabolismo , Animales , Línea Celular , Línea Celular Tumoral , Células HCT116 , Células HEK293 , Células HT29 , Humanos , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Óxido Nítrico Sintasa/metabolismo , Fosforilación/fisiología , Complejo de la Endopetidasa Proteasomal/metabolismo , Proteolisis , Transducción de Señal/fisiología , Factor de Crecimiento Transformador beta/metabolismo
7.
Nat Methods ; 2024 Oct 31.
Artículo en Inglés | MEDLINE | ID: mdl-39482464

RESUMEN

Advancing data analysis tools for proteome-wide cross-linking mass spectrometry (XL-MS) requires ground-truth standards that mimic biological complexity. Here we develop well-controlled XL-MS standards comprising hundreds of recombinant proteins that are systematically mixed for cross-linking. We use one standard dataset to guide the development of Scout, a search engine for XL-MS with MS-cleavable cross-linkers. Using other, independent standard datasets and published datasets, we benchmark the performance of Scout and existing XL-MS software. We find that Scout offers an excellent combination of speed, sensitivity and false discovery rate control. The results illustrate how our large recombinant standard can support the development of XL-MS analysis tools and evaluation of XL-MS results.

8.
J Immunol ; 212(7): 1207-1220, 2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-38345351

RESUMEN

Teleost fish type I IFNs and the associated receptors from the cytokine receptor family B (CRFB) are characterized by remarkable diversity and complexity. How the fish type I IFNs bind to their receptors is still not fully understood. In this study, we demonstrate that CRFB1 and CRFB5 constitute the receptor pair through which type I subgroup d IFN (IFNd) from large yellow croaker, Larimichthys crocea, activates the conserved JAK-STAT signaling pathway as a part of the antiviral response. Our data suggest that L. crocea IFNd (LcIFNd) has a higher binding affinity with L. crocea CRFB5 (LcCRFB5) than with LcCRFB1. Furthermore, we report the crystal structure of LcIFNd at a 1.49-Å resolution and construct structural models of LcIFNd in binary complexes with predicted structures of extracellular regions of LcCRFB1 and LcCRFB5, respectively. Despite striking similarities in overall architectures of LcIFNd and its ortholog human IFN-ω, the receptor binding patterns between LcIFNd and its receptors show that teleost and mammalian type I IFNs may have differentially selected helices that bind to their homologous receptors. Correspondingly, key residues mediating binding of LcIFNd to LcCRFB1 and LcCRFB5 are largely distinct from the receptor-interacting residues in other fish and mammalian type I IFNs. Our findings reveal a ligand/receptor complex binding mechanism of IFNd in teleost fish, thus providing new insights into the function and evolution of type I IFNs.


Asunto(s)
Interferón Tipo I , Perciformes , Animales , Humanos , Filogenia , Peces/metabolismo , Interferón Tipo I/metabolismo , Proteínas de Peces/genética , Mamíferos/metabolismo
9.
Nature ; 580(7805): 653-657, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-32350464

RESUMEN

The aboveground parts of terrestrial plants, collectively called the phyllosphere, have a key role in the global balance of atmospheric carbon dioxide and oxygen. The phyllosphere represents one of the most abundant habitats for microbiota colonization. Whether and how plants control phyllosphere microbiota to ensure plant health is not well understood. Here we show that the Arabidopsis quadruple mutant (min7 fls2 efr cerk1; hereafter, mfec)1, simultaneously defective in pattern-triggered immunity and the MIN7 vesicle-trafficking pathway, or a constitutively activated cell death1 (cad1) mutant, carrying a S205F mutation in a membrane-attack-complex/perforin (MACPF)-domain protein, harbour altered endophytic phyllosphere microbiota and display leaf-tissue damage associated with dysbiosis. The Shannon diversity index and the relative abundance of Firmicutes were markedly reduced, whereas Proteobacteria were enriched in the mfec and cad1S205F mutants, bearing cross-kingdom resemblance to some aspects of the dysbiosis that occurs in human inflammatory bowel disease. Bacterial community transplantation experiments demonstrated a causal role of a properly assembled leaf bacterial community in phyllosphere health. Pattern-triggered immune signalling, MIN7 and CAD1 are found in major land plant lineages and are probably key components of a genetic network through which terrestrial plants control the level and nurture the diversity of endophytic phyllosphere microbiota for survival and health in a microorganism-rich environment.


Asunto(s)
Arabidopsis/genética , Arabidopsis/microbiología , Redes Reguladoras de Genes/genética , Componentes Aéreos de las Plantas/genética , Componentes Aéreos de las Plantas/microbiología , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/prevención & control , Arabidopsis/inmunología , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Muerte Celular , Ambiente , Firmicutes/genética , Firmicutes/aislamiento & purificación , Genes de Plantas/genética , Genotipo , Factores de Intercambio de Guanina Nucleótido/genética , Factores de Intercambio de Guanina Nucleótido/metabolismo , Homeostasis , Microbiota/genética , Microbiota/fisiología , Mutación , Fenotipo , Enfermedades de las Plantas/inmunología , Enfermedades de las Plantas/microbiología , Inmunidad de la Planta/genética , Hojas de la Planta/genética , Hojas de la Planta/microbiología , Proteobacteria/genética , Proteobacteria/aislamiento & purificación
10.
Nature ; 577(7790): 341-345, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31942054

RESUMEN

Classification is an important task at which both biological and artificial neural networks excel1,2. In machine learning, nonlinear projection into a high-dimensional feature space can make data linearly separable3,4, simplifying the classification of complex features. Such nonlinear projections are computationally expensive in conventional computers. A promising approach is to exploit physical materials systems that perform this nonlinear projection intrinsically, because of their high computational density5, inherent parallelism and energy efficiency6,7. However, existing approaches either rely on the systems' time dynamics, which requires sequential data processing and therefore hinders parallel computation5,6,8, or employ large materials systems that are difficult to scale up7. Here we use a parallel, nanoscale approach inspired by filters in the brain1 and artificial neural networks2 to perform nonlinear classification and feature extraction. We exploit the nonlinearity of hopping conduction9-11 through an electrically tunable network of boron dopant atoms in silicon, reconfiguring the network through artificial evolution to realize different computational functions. We first solve the canonical two-input binary classification problem, realizing all Boolean logic gates12 up to room temperature, demonstrating nonlinear classification with the nanomaterial system. We then evolve our dopant network to realize feature filters2 that can perform four-input binary classification on the Modified National Institute of Standards and Technology handwritten digit database. Implementation of our material-based filters substantially improves the classification accuracy over that of a linear classifier directly applied to the original data13. Our results establish a paradigm of silicon-based electronics for small-footprint and energy-efficient computation14.

11.
Mol Cell ; 70(5): 801-813.e6, 2018 06 07.
Artículo en Inglés | MEDLINE | ID: mdl-29804829

RESUMEN

The RNA-guided DNA endonuclease Cas9 is a powerful tool for genome editing. Little is known about the kinetics and fidelity of the double-strand break (DSB) repair process that follows a Cas9 cutting event in living cells. Here, we developed a strategy to measure the kinetics of DSB repair for single loci in human cells. Quantitative modeling of repaired DNA in time series after Cas9 activation reveals variable and often slow repair rates, with half-life times up to ∼10 hr. Furthermore, repair of the DSBs tends to be error prone. Both classical and microhomology-mediated end joining pathways contribute to the erroneous repair. Estimation of their individual rate constants indicates that the balance between these two pathways changes over time and can be altered by additional ionizing radiation. Our approach provides quantitative insights into DSB repair kinetics and fidelity in single loci and indicates that Cas9-induced DSBs are repaired in an unusual manner.


Asunto(s)
Proteína 9 Asociada a CRISPR/genética , Sistemas CRISPR-Cas , Repeticiones Palindrómicas Cortas Agrupadas y Regularmente Espaciadas , Roturas del ADN de Doble Cadena , Reparación del ADN por Unión de Extremidades , Edición Génica/métodos , Proteína 9 Asociada a CRISPR/metabolismo , Humanos , Mutación INDEL , Células K562 , Cinética , Modelos Genéticos
12.
Artículo en Inglés | MEDLINE | ID: mdl-39307891

RESUMEN

Mitochondria are central actors in diverse physiological phenomena ranging from energy metabolism to stress signaling and immune modulation. Accumulating scientific evidence points to the critical involvement of specific mitochondrial-associated events, including mitochondrial quality control, intercellular mitochondrial transfer, and mitochondrial genetics, in potentiating the metastatic cascade of neoplastic cells. Furthermore, numerous recent studies have consistently emphasized the highly significant role mitochondria play in coordinating the regulation of tumor-infiltrating immune cells and immunotherapeutic interventions. This review provides a comprehensive and rigorous scholarly investigation of this subject matter, exploring the intricate mechanisms by which mitochondria contribute to tumor metastasis and examining the progress of mitochondria-targeted cancer therapies.

13.
EMBO J ; 40(10): e106632, 2021 05 17.
Artículo en Inglés | MEDLINE | ID: mdl-33739466

RESUMEN

HIV-1 latency is a major obstacle to achieving a functional cure for AIDS. Reactivation of HIV-1-infected cells followed by their elimination via immune surveillance is one proposed strategy for eradicating the viral reservoir. However, current latency-reversing agents (LRAs) show high toxicity and low efficiency, and new targets are needed to develop more promising LRAs. Here, we found that the histone chaperone CAF-1 (chromatin assembly factor 1) is enriched on the HIV-1 long terminal repeat (LTR) and forms nuclear bodies with liquid-liquid phase separation (LLPS) properties. CAF-1 recruits epigenetic modifiers and histone chaperones to the nuclear bodies to establish and maintain HIV-1 latency in different latency models and primary CD4+ T cells. Three disordered regions of the CHAF1A subunit are important for phase-separated CAF-1 nuclear body formation and play a key role in maintaining HIV-1 latency. Disruption of phase-separated CAF-1 bodies could be a potential strategy to reactivate latent HIV-1.


Asunto(s)
VIH-1/metabolismo , Linfocitos T CD4-Positivos/metabolismo , Factor 1 de Ensamblaje de la Cromatina/genética , Factor 1 de Ensamblaje de la Cromatina/metabolismo , Epigénesis Genética/genética , Epigénesis Genética/fisiología , Células HEK293 , Humanos , Regiones Promotoras Genéticas/genética
14.
N Engl J Med ; 386(12): 1109-1120, 2022 03 24.
Artículo en Inglés | MEDLINE | ID: mdl-35320642

RESUMEN

BACKGROUND: Cryptococcal meningitis is a leading cause of human immunodeficiency virus (HIV)-related death in sub-Saharan Africa. Whether a treatment regimen that includes a single high dose of liposomal amphotericin B would be efficacious is not known. METHODS: In this phase 3 randomized, controlled, noninferiority trial conducted in five African countries, we assigned HIV-positive adults with cryptococcal meningitis in a 1:1 ratio to receive either a single high dose of liposomal amphotericin B (10 mg per kilogram of body weight) on day 1 plus 14 days of flucytosine (100 mg per kilogram per day) and fluconazole (1200 mg per day) or the current World Health Organization-recommended treatment, which includes amphotericin B deoxycholate (1 mg per kilogram per day) plus flucytosine (100 mg per kilogram per day) for 7 days, followed by fluconazole (1200 mg per day) for 7 days (control). The primary end point was death from any cause at 10 weeks; the trial was powered to show noninferiority at a 10-percentage-point margin. RESULTS: A total of 844 participants underwent randomization; 814 were included in the intention-to-treat population. At 10 weeks, deaths were reported in 101 participants (24.8%; 95% confidence interval [CI], 20.7 to 29.3) in the liposomal amphotericin B group and 117 (28.7%; 95% CI, 24.4 to 33.4) in the control group (difference, -3.9 percentage points); the upper boundary of the one-sided 95% confidence interval was 1.2 percentage points (within the noninferiority margin; P<0.001 for noninferiority). Fungal clearance from cerebrospinal fluid was -0.40 log10 colony-forming units (CFU) per milliliter per day in the liposomal amphotericin B group and -0.42 log10 CFU per milliliter per day in the control group. Fewer participants had grade 3 or 4 adverse events in the liposomal amphotericin B group than in the control group (50.0% vs. 62.3%). CONCLUSIONS: Single-dose liposomal amphotericin B combined with flucytosine and fluconazole was noninferior to the WHO-recommended treatment for HIV-associated cryptococcal meningitis and was associated with fewer adverse events. (Funded by the European and Developing Countries Clinical Trials Partnership and others; Ambition ISRCTN number, ISRCTN72509687.).


Asunto(s)
Infecciones Oportunistas Relacionadas con el SIDA/tratamiento farmacológico , Anfotericina B/administración & dosificación , Antifúngicos/administración & dosificación , Fluconazol/administración & dosificación , Flucitosina/administración & dosificación , Meningitis Criptocócica/tratamiento farmacológico , Infecciones Oportunistas Relacionadas con el SIDA/mortalidad , Administración Oral , África del Sur del Sahara , Anfotericina B/efectos adversos , Antifúngicos/efectos adversos , Esquema de Medicación , Quimioterapia Combinada , Fluconazol/efectos adversos , Flucitosina/efectos adversos , Infecciones por VIH/complicaciones , Meningitis Criptocócica/mortalidad
15.
J Virol ; 98(8): e0003524, 2024 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-39082875

RESUMEN

The human immunodeficiency virus type 1 (HIV-1) reservoir consists of latently infected cells which present a major obstacle to achieving a functional cure for HIV-1. The formation and maintenance of HIV-1 latency have been extensively studied, and latency-reversing agents (LRAs) that can reactivate latent HIV-1 by targeting the involved host factors are developed; however, their clinical efficacies remain unsatisfactory. Therefore, it is imperative to identify novel targets for more potential candidates or better combinations for LRAs. In this study, we utilized CRISPR affinity purification in situ of regulatory elements system to screen for host factors associated with the HIV-1 long terminal repeat region that could potentially be involved in HIV-1 latency. We successfully identified that origin recognition complex 1 (ORC1), the largest subunit of the origin recognition complex, contributes to HIV-1 latency in addition to its function in DNA replication initiation. Notably, ORC1 is enriched on the HIV-1 promoter and recruits a series of repressive epigenetic elements, including DNMT1 and HDAC1/2, and histone modifiers, such as H3K9me3 and H3K27me3, thereby facilitating the establishment and maintenance of HIV-1 latency. Moreover, the reactivation of latent HIV-1 through ORC1 depletion has been confirmed across various latency cell models and primary CD4+ T cells from people living with HIV-1. Additionally, we comprehensively validated the properties of liquid-liquid phase separation (LLPS) of ORC1 from multiple perspectives and identified the key regions that promote the formation of LLPS. This property is important for the recruitment of ORC1 to the HIV-1 promoter. Collectively, these findings highlight ORC1 as a potential novel target implicated in HIV-1 latency and position it as a promising candidate for the development of novel LRAs. IMPORTANCE: Identifying host factors involved in maintaining human immunodeficiency virus type 1 (HIV-1) latency and understanding their mechanisms prepares the groundwork to discover novel targets for HIV-1 latent infection and provides further options for the selection of latency-reversing agents in the "shock" strategy. In this study, we identified a novel role of the DNA replication factor origin recognition complex 1 (ORC1) in maintaining repressive chromatin structures surrounding the HIV-1 promoter region, thereby contributing to HIV-1 latency. This discovery expands our understanding of the non-replicative functions of the ORC complex and provides a potential therapeutic strategy for HIV-1 cure.


Asunto(s)
Epigénesis Genética , Infecciones por VIH , Duplicado del Terminal Largo de VIH , VIH-1 , Complejo de Reconocimiento del Origen , Regiones Promotoras Genéticas , Latencia del Virus , Latencia del Virus/genética , Humanos , VIH-1/genética , VIH-1/fisiología , Duplicado del Terminal Largo de VIH/genética , Infecciones por VIH/virología , Infecciones por VIH/genética , Infecciones por VIH/metabolismo , Complejo de Reconocimiento del Origen/metabolismo , Complejo de Reconocimiento del Origen/genética , Linfocitos T CD4-Positivos/virología , Células HEK293 , ADN (Citosina-5-)-Metiltransferasa 1/metabolismo , ADN (Citosina-5-)-Metiltransferasa 1/genética , Histona Desacetilasa 1/metabolismo , Histona Desacetilasa 1/genética , Histona Desacetilasa 2/metabolismo , Histona Desacetilasa 2/genética , Regulación Viral de la Expresión Génica , Replicación Viral , Histonas/metabolismo , Histonas/genética
16.
Plant Physiol ; 194(3): 1764-1778, 2024 Feb 29.
Artículo en Inglés | MEDLINE | ID: mdl-38035763

RESUMEN

Clubroot, caused by the soil-borne protist pathogen Plasmodiophora brassicae, is one of the most devastating diseases of Brassica oil and vegetable crops worldwide. Understanding the pathogen infection strategy is crucial for the development of disease control. However, because of its obligate biotrophic nature, the molecular mechanism by which this pathogen promotes infection remains largely unknown. P. brassicae E3 ubiquitin ligase 2 (PbE3-2) is a Really Interesting New Gene (RING)-type E3 ubiquitin ligase in P. brassicae with E3 ligase activity in vitro. Yeast (Saccharomyces cerevisiae) invertase assay and apoplast washing fluid extraction showed that PbE3-2 harbors a functional signal peptide. Overexpression of PbE3-2 in Arabidopsis (Arabidopsis thaliana) resulted in higher susceptibility to P. brassicae and decreases in chitin-triggered reactive oxygen species burst and expression of marker genes in salicylic acid signaling. PbE3-2 interacted with and ubiquitinated host cysteine protease RESPONSIVE TO DEHYDRATION 21A (RD21A) in vitro and in vivo. Mutant plants deficient in RD21A exhibited similar susceptibility and compromised immune responses as in PbE3-2 overexpression plants. We show that PbE3-2, which targets RD21A, is an important virulence factor for P. brassicae. Two other secretory RING-type E3 ubiquitin ligases in P. brassicae performed the same function as PbE3-2 and ubiquitinated RD21A. This study reveals a substantial virulence functional role of protist E3 ubiquitin ligases and demonstrates a mechanism by which protist E3 ubiquitin ligases degrade host immune-associated cysteine proteases to impede host immunity.


Asunto(s)
Arabidopsis , Proteasas de Cisteína , Arabidopsis/genética , Proteasas de Cisteína/genética , Inmunidad de la Planta/genética , Saccharomyces cerevisiae , Ubiquitina , Ubiquitina-Proteína Ligasas/genética , Ubiquitinación
17.
Plant Cell ; 34(10): 3718-3736, 2022 09 27.
Artículo en Inglés | MEDLINE | ID: mdl-35861414

RESUMEN

Pollen tube guidance regulates the growth direction and ovule targeting of pollen tubes in pistils, which is crucial for the completion of sexual reproduction in flowering plants. The Arabidopsis (Arabidopsis thaliana) pollen-specific receptor kinase (PRK) family members PRK3 and PRK6 are specifically tip-localized and essential for pollen tube growth and guidance. However, the mechanisms controlling the polar localization of PRKs at the pollen tube tip are unclear. The Arabidopsis P4-ATPase ALA3 helps establish the polar localization of apical phosphatidylserine (PS) in pollen tubes. Here, we discovered that loss of ALA3 function caused pollen tube defects in growth and ovule targeting and significantly affected the polar localization pattern of PRK3 and PRK6. Both PRK3 and PRK6 contain two polybasic clusters in the intracellular juxtamembrane domain, and they bound to PS in vitro. PRK3 and PRK6 with polybasic cluster mutations showed reduced or abolished binding to PS and altered polar localization patterns, and they failed to effectively complement the pollen tube-related phenotypes of prk mutants. These results suggest that ALA3 influences the precise localization of PRK3, PRK6, and other PRKs by regulating the distribution of PS, which plays a key role in regulating pollen tube growth and guidance.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Adenosina Trifosfatasas/metabolismo , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Fosfatidilserinas/metabolismo , Fosfolípidos/metabolismo , Tubo Polínico , Proteínas Serina-Treonina Quinasas
18.
Mol Psychiatry ; 2024 Jul 13.
Artículo en Inglés | MEDLINE | ID: mdl-39003414

RESUMEN

Neuroligin-3 (Nlgn3) is an autism-associated cell-adhesion molecule that interacts with neurexins and is robustly expressed in both neurons and astrocytes. Neuronal Nlgn3 is an essential regulator of synaptic transmission but the function of astrocytic Nlgn3 is largely unknown. Given the high penetrance of Nlgn3 mutations in autism and the emerging role of astrocytes in neuropsychiatric disorders, we here asked whether astrocytic Nlgn3 might shape neural circuit properties in the cerebellum similar to neuronal Nlgn3. Imaging of tagged Nlgn3 protein produced by CRISPR/Cas9-mediated genome editing showed that Nlgn3 is enriched in the cell body but not the fine processes of cerebellar astrocytes (Bergmann glia). Astrocyte-specific knockout of Nlgn3 did not detectably alter the number of synapses, synaptic transmission, or astrocyte morphology in mouse cerebellum. However, spatial transcriptomic analyses revealed a significant shift in gene expression among multiple cerebellar cell types after the deletion of astrocytic Nlgn3. Hence, in contrast to neuronal Nlgn3, astrocytic Nlgn3 in the cerebellum is not involved in shaping synapses but may modulate gene expression in specific brain areas.

19.
PLoS Biol ; 20(7): e3001699, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35776767

RESUMEN

Both the composition of cell types and their spatial distribution in a tissue play a critical role in cellular function, organ development, and disease progression. For example, intratumor heterogeneity and the distribution of transcriptional and genetic events in single cells drive the genesis and development of cancer. However, it can be challenging to fully characterize the molecular profile of cells in a tissue with high spatial resolution because microscopy has limited ability to extract comprehensive genomic information, and the spatial resolution of genomic techniques tends to be limited by dissection. There is a growing need for tools that can be used to explore the relationship between histological features, gene expression patterns, and spatially correlated genomic alterations in healthy and diseased tissue samples. Here, we present a technique that combines label-free histology with spatially resolved multiomics in unfixed and unstained tissue sections. This approach leverages stimulated Raman scattering microscopy to provide chemical contrast that reveals histological tissue architecture, allowing for high-resolution in situ laser microdissection of regions of interests. These microtissue samples are then processed for DNA and RNA sequencing to identify unique genetic profiles that correspond to distinct anatomical regions. We demonstrate the capabilities of this technique by mapping gene expression and copy number alterations to histologically defined regions in human oral squamous cell carcinoma (OSCC). Our approach provides complementary insights in tumorigenesis and offers an integrative tool for macroscale cancer tissues with spatial multiomics assessments.


Asunto(s)
Carcinoma de Células Escamosas , Neoplasias de la Boca , Carcinoma de Células Escamosas/genética , Variaciones en el Número de Copia de ADN/genética , Perfilación de la Expresión Génica/métodos , Genómica , Humanos , Análisis de Secuencia de ARN
20.
PLoS Genet ; 18(9): e1010351, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-36048878

RESUMEN

Advances in genomic technology led to a more focused pattern for the distribution of chromosomal proteins and a better understanding of their functions. The recent development of the CUT&RUN technique marks one of the important such advances. Here we develop a modified CUT&RUN technique that we termed nanoCUT&RUN, in which a high affinity nanobody to GFP is used to bring micrococcal nuclease to the binding sites of GFP-tagged chromatin proteins. Subsequent activation of the nuclease cleaves the chromatin, and sequencing of released DNA identifies binding sites. We show that nanoCUT&RUN efficiently produces high quality data for the TRL transcription factor in Drosophila embryos, and distinguishes binding sites specific between two TRL isoforms. We further show that nanoCUT&RUN dissects the distributions of the HipHop and HOAP telomere capping proteins, and uncovers unexpected binding of telomeric proteins at centromeres. nanoCUT&RUN can be readily applied to any system in which a chromatin protein of interest, or its isoforms, carries the GFP tag.


Asunto(s)
Proteínas de Drosophila , Drosophila , Animales , Cromatina/genética , Cromatina/metabolismo , Proteínas Cromosómicas no Histona/genética , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Drosophila/genética , Proteínas de Drosophila/metabolismo , Telómero/genética , Telómero/metabolismo , Factores de Transcripción/genética
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