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1.
Immunity ; 57(6): 1306-1323.e8, 2024 Jun 11.
Artículo en Inglés | MEDLINE | ID: mdl-38815582

RESUMEN

Group 3 innate lymphoid cells (ILC3s) regulate inflammation and tissue repair at mucosal sites, but whether these functions pertain to other tissues-like the kidneys-remains unclear. Here, we observed that renal fibrosis in humans was associated with increased ILC3s in the kidneys and blood. In mice, we showed that CXCR6+ ILC3s rapidly migrated from the intestinal mucosa and accumulated in the kidney via CXCL16 released from the injured tubules. Within the fibrotic kidney, ILC3s increased the expression of programmed cell death-1 (PD-1) and subsequent IL-17A production to directly activate myofibroblasts and fibrotic niche formation. ILC3 expression of PD-1 inhibited IL-23R endocytosis and consequently amplified the JAK2/STAT3/RORγt/IL-17A pathway that was essential for the pro-fibrogenic effect of ILC3s. Thus, we reveal a hitherto unrecognized migration pathway of ILC3s from the intestine to the kidney and the PD-1-dependent function of ILC3s in promoting renal fibrosis.


Asunto(s)
Movimiento Celular , Fibrosis , Riñón , Linfocitos , Receptor de Muerte Celular Programada 1 , Receptores CXCR6 , Receptores de Interleucina , Transducción de Señal , Animales , Fibrosis/inmunología , Ratones , Receptores CXCR6/metabolismo , Receptores CXCR6/inmunología , Receptor de Muerte Celular Programada 1/metabolismo , Transducción de Señal/inmunología , Movimiento Celular/inmunología , Humanos , Riñón/patología , Riñón/inmunología , Riñón/metabolismo , Linfocitos/inmunología , Linfocitos/metabolismo , Receptores de Interleucina/metabolismo , Receptores de Interleucina/inmunología , Ratones Endogámicos C57BL , Enfermedades Renales/inmunología , Enfermedades Renales/metabolismo , Enfermedades Renales/patología , Inmunidad Innata/inmunología , Ratones Noqueados , Mucosa Intestinal/inmunología , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patología , Intestinos/inmunología , Intestinos/patología
2.
Cell ; 169(6): 1090-1104.e13, 2017 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-28552346

RESUMEN

Genetic studies have elucidated critical roles of Piwi proteins in germline development in animals, but whether Piwi is an actual disease gene in human infertility remains unknown. We report germline mutations in human Piwi (Hiwi) in patients with azoospermia that prevent its ubiquitination and degradation. By modeling such mutations in Piwi (Miwi) knockin mice, we demonstrate that the genetic defects are directly responsible for male infertility. Mechanistically, we show that MIWI binds the histone ubiquitin ligase RNF8 in a Piwi-interacting RNA (piRNA)-independent manner, and MIWI stabilization sequesters RNF8 in the cytoplasm of late spermatids. The resulting aberrant sperm show histone retention, abnormal morphology, and severely compromised activity, which can be functionally rescued via blocking RNF8-MIWI interaction in spermatids with an RNF8-N peptide. Collectively, our findings identify Piwi as a factor in human infertility and reveal its role in regulating the histone-to-protamine exchange during spermiogenesis.


Asunto(s)
Proteínas Argonautas/genética , Proteínas Argonautas/metabolismo , Azoospermia/genética , Mutación , Animales , Azoospermia/metabolismo , Cromatina/metabolismo , Análisis Mutacional de ADN , Proteínas de Unión al ADN/metabolismo , Modelos Animales de Enfermedad , Femenino , Técnicas de Sustitución del Gen , Histonas/metabolismo , Humanos , Intrones , Masculino , Ratones , Linaje , Protaminas/metabolismo , Proteolisis , Espermatogénesis , Ubiquitina-Proteína Ligasas , Ubiquitinación
3.
Nature ; 627(8002): 157-164, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38418877

RESUMEN

The accumulation of metabolic waste is a leading cause of numerous neurological disorders, yet we still have only limited knowledge of how the brain performs self-cleansing. Here we demonstrate that neural networks synchronize individual action potentials to create large-amplitude, rhythmic and self-perpetuating ionic waves in the interstitial fluid of the brain. These waves are a plausible mechanism to explain the correlated potentiation of the glymphatic flow1,2 through the brain parenchyma. Chemogenetic flattening of these high-energy ionic waves largely impeded cerebrospinal fluid infiltration into and clearance of molecules from the brain parenchyma. Notably, synthesized waves generated through transcranial optogenetic stimulation substantially potentiated cerebrospinal fluid-to-interstitial fluid perfusion. Our study demonstrates that neurons serve as master organizers for brain clearance. This fundamental principle introduces a new theoretical framework for the functioning of macroscopic brain waves.


Asunto(s)
Encéfalo , Líquido Cefalorraquídeo , Líquido Extracelular , Neuronas , Potenciales de Acción , Encéfalo/citología , Encéfalo/metabolismo , Ondas Encefálicas/fisiología , Líquido Cefalorraquídeo/metabolismo , Líquido Extracelular/metabolismo , Sistema Glinfático/metabolismo , Cinética , Red Nerviosa/fisiología , Neuronas/metabolismo , Optogenética , Tejido Parenquimatoso/metabolismo , Iones/metabolismo
4.
Nature ; 629(8011): 355-362, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38720042

RESUMEN

The coupling of excitons in π-conjugated molecules to high-frequency vibrational modes, particularly carbon-carbon stretch modes (1,000-1,600 cm-1) has been thought to be unavoidable1,2. These high-frequency modes accelerate non-radiative losses and limit the performance of light-emitting diodes, fluorescent biomarkers and photovoltaic devices. Here, by combining broadband impulsive vibrational spectroscopy, first-principles modelling and synthetic chemistry, we explore exciton-vibration coupling in a range of π-conjugated molecules. We uncover two design rules that decouple excitons from high-frequency vibrations. First, when the exciton wavefunction has a substantial charge-transfer character with spatially disjoint electron and hole densities, we find that high-frequency modes can be localized to either the donor or acceptor moiety, so that they do not significantly perturb the exciton energy or its spatial distribution. Second, it is possible to select materials such that the participating molecular orbitals have a symmetry-imposed non-bonding character and are, thus, decoupled from the high-frequency vibrational modes that modulate the π-bond order. We exemplify both these design rules by creating a series of spin radical systems that have very efficient near-infrared emission (680-800 nm) from charge-transfer excitons. We show that these systems have substantial coupling to vibrational modes only below 250 cm-1, frequencies that are too low to allow fast non-radiative decay. This enables non-radiative decay rates to be suppressed by nearly two orders of magnitude in comparison to π-conjugated molecules with similar bandgaps. Our results show that losses due to coupling to high-frequency modes need not be a fundamental property of these systems.

5.
Nature ; 620(7974): 538-544, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37587296

RESUMEN

Molecules present a versatile platform for quantum information science1,2 and are candidates for sensing and computation applications3,4. Robust spin-optical interfaces are key to harnessing the quantum resources of materials5. To date, carbon-based candidates have been non-luminescent6,7, which prevents optical readout via emission. Here we report organic molecules showing both efficient luminescence and near-unity generation yield of excited states with spin multiplicity S > 1. This was achieved by designing an energy resonance between emissive doublet and triplet levels, here on covalently coupled tris(2,4,6-trichlorophenyl) methyl-carbazole radicals and anthracene. We observed that the doublet photoexcitation delocalized onto the linked acene within a few picoseconds and subsequently evolved to a pure high-spin state (quartet for monoradical, quintet for biradical) of mixed radical-triplet character near 1.8 eV. These high-spin states are coherently addressable with microwaves even at 295 K, with optical readout enabled by reverse intersystem crossing to emissive states. Furthermore, for the biradical, on return to the ground state the previously uncorrelated radical spins either side of the anthracene shows strong spin correlation. Our approach simultaneously supports a high efficiency of initialization, spin manipulations and light-based readout at room temperature. The integration of luminescence and high-spin states creates an organic materials platform for emerging quantum technologies.

6.
Nature ; 616(7955): 77-83, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-37020008

RESUMEN

Inorganic superionic conductors possess high ionic conductivity and excellent thermal stability but their poor interfacial compatibility with lithium metal electrodes precludes application in all-solid-state lithium metal batteries1,2. Here we report a LaCl3-based lithium superionic conductor possessing excellent interfacial compatibility with lithium metal electrodes. In contrast to a Li3MCl6 (M = Y, In, Sc and Ho) electrolyte lattice3-6, the UCl3-type LaCl3 lattice has large, one-dimensional channels for rapid Li+ conduction, interconnected by La vacancies via Ta doping and resulting in a three-dimensional Li+ migration network. The optimized Li0.388Ta0.238La0.475Cl3 electrolyte exhibits Li+ conductivity of 3.02 mS cm-1 at 30 °C and a low activation energy of 0.197 eV. It also generates a gradient interfacial passivation layer to stabilize the Li metal electrode for long-term cycling of a Li-Li symmetric cell (1 mAh cm-2) for more than 5,000 h. When directly coupled with an uncoated LiNi0.5Co0.2Mn0.3O2 cathode and bare Li metal anode, the Li0.388Ta0.238La0.475Cl3 electrolyte enables a solid battery to run for more than 100 cycles with a cutoff voltage of 4.35 V and areal capacity of more than 1 mAh cm-2. We also demonstrate rapid Li+ conduction in lanthanide metal chlorides (LnCl3; Ln = La, Ce, Nd, Sm and Gd), suggesting that the LnCl3 solid electrolyte system could provide further developments in conductivity and utility.

7.
Nature ; 622(7982): 393-401, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37821590

RESUMEN

Recent human decedent model studies1,2 and compassionate xenograft use3 have explored the promise of porcine organs for human transplantation. To proceed to human studies, a clinically ready porcine donor must be engineered and its xenograft successfully tested in nonhuman primates. Here we describe the design, creation and long-term life-supporting function of kidney grafts from a genetically engineered porcine donor transplanted into a cynomolgus monkey model. The porcine donor was engineered to carry 69 genomic edits, eliminating glycan antigens, overexpressing human transgenes and inactivating porcine endogenous retroviruses. In vitro functional analyses showed that the edited kidney endothelial cells modulated inflammation to an extent that was indistinguishable from that of human endothelial cells, suggesting that these edited cells acquired a high level of human immune compatibility. When transplanted into cynomolgus monkeys, the kidneys with three glycan antigen knockouts alone experienced poor graft survival, whereas those with glycan antigen knockouts and human transgene expression demonstrated significantly longer survival time, suggesting the benefit of human transgene expression in vivo. These results show that preclinical studies of renal xenotransplantation could be successfully conducted in nonhuman primates and bring us closer to clinical trials of genetically engineered porcine renal grafts.


Asunto(s)
Rechazo de Injerto , Trasplante de Riñón , Macaca fascicularis , Porcinos , Trasplante Heterólogo , Animales , Humanos , Animales Modificados Genéticamente , Células Endoteliales/inmunología , Células Endoteliales/metabolismo , Rechazo de Injerto/inmunología , Rechazo de Injerto/prevención & control , Trasplante de Riñón/métodos , Polisacáridos/deficiencia , Porcinos/genética , Trasplante Heterólogo/métodos , Transgenes/genética
8.
Cell ; 153(3): 590-600, 2013 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-23622243

RESUMEN

DNA mismatch repair (MMR) ensures replication fidelity by correcting mismatches generated during DNA replication. Although human MMR has been reconstituted in vitro, how MMR occurs in vivo is unknown. Here, we show that an epigenetic histone mark, H3K36me3, is required in vivo to recruit the mismatch recognition protein hMutSα (hMSH2-hMSH6) onto chromatin through direct interactions with the hMSH6 PWWP domain. The abundance of H3K36me3 in G1 and early S phases ensures that hMutSα is enriched on chromatin before mispairs are introduced during DNA replication. Cells lacking the H3K36 trimethyltransferase SETD2 display microsatellite instability (MSI) and an elevated spontaneous mutation frequency, characteristic of MMR-deficient cells. This work reveals that a histone mark regulates MMR in human cells and explains the long-standing puzzle of MSI-positive cancer cells that lack detectable mutations in known MMR genes.


Asunto(s)
Reparación de la Incompatibilidad de ADN , Proteínas de Unión al ADN/metabolismo , Código de Histonas , Secuencia de Aminoácidos , Cromatina/metabolismo , Proteínas de Unión al ADN/química , Humanos , Metilación , Modelos Moleculares , Datos de Secuencia Molecular , Estructura Terciaria de Proteína , Alineación de Secuencia
9.
Mol Cell ; 80(3): 410-422.e6, 2020 11 05.
Artículo en Inglés | MEDLINE | ID: mdl-33108758

RESUMEN

While effective anti-cancer drugs targeting the CHK1 kinase are advancing in the clinic, drug resistance is rapidly emerging. Here, we demonstrate that CRISPR-mediated knockout of the little-known gene FAM122A/PABIR1 confers cellular resistance to CHK1 inhibitors (CHK1is) and cross-resistance to ATR inhibitors. Knockout of FAM122A results in activation of PP2A-B55α, a phosphatase that dephosphorylates the WEE1 protein and rescues WEE1 from ubiquitin-mediated degradation. The resulting increase in WEE1 protein expression reduces replication stress, activates the G2/M checkpoint, and confers cellular resistance to CHK1is. Interestingly, in tumor cells with oncogene-driven replication stress, CHK1 can directly phosphorylate FAM122A, leading to activation of the PP2A-B55α phosphatase and increased WEE1 expression. A combination of a CHK1i plus a WEE1 inhibitor can overcome CHK1i resistance of these tumor cells, thereby enhancing anti-cancer activity. The FAM122A expression level in a tumor cell can serve as a useful biomarker for predicting CHK1i sensitivity or resistance.


Asunto(s)
Quinasa 1 Reguladora del Ciclo Celular (Checkpoint 1)/genética , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Fosfoproteínas/metabolismo , Pirazinas/farmacología , Pirazoles/farmacología , Animales , Apoptosis/efectos de los fármacos , Puntos de Control del Ciclo Celular , Proteínas de Ciclo Celular/metabolismo , Línea Celular , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Quinasa 1 Reguladora del Ciclo Celular (Checkpoint 1)/antagonistas & inhibidores , Quinasa 1 Reguladora del Ciclo Celular (Checkpoint 1)/metabolismo , Daño del ADN/efectos de los fármacos , Puntos de Control de la Fase G2 del Ciclo Celular/efectos de los fármacos , Humanos , Péptidos y Proteínas de Señalización Intracelular/fisiología , Proteínas Nucleares/metabolismo , Fosfoproteínas/fisiología , Fosforilación , Inhibidores de Proteínas Quinasas/farmacología , Procesamiento Proteico-Postraduccional/efectos de los fármacos , Proteínas Tirosina Quinasas/genética , Pirazinas/metabolismo , Pirazoles/metabolismo , Transducción de Señal/efectos de los fármacos
10.
Plant Cell ; 36(2): 298-323, 2024 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-37847093

RESUMEN

The high-yielding Green Revolution varieties of cereal crops are characterized by a semidwarf architecture and lodging resistance. Plant height is tightly regulated by the availability of phosphate (Pi), yet the underlying mechanism remains obscure. Here, we report that rice (Oryza sativa) R2R3-type Myeloblastosis (MYB) transcription factor MYB110 is a Pi-dependent negative regulator of plant height. MYB110 is a direct target of PHOSPHATE STARVATION RESPONSE 2 (OsPHR2) and regulates OsPHR2-mediated inhibition of rice height. Inactivation of MYB110 increased culm diameter and bending resistance, leading to enhanced lodging resistance despite increased plant height. Strikingly, the grain yield of myb110 mutants was elevated under both high- and low-Pi regimes. Two divergent haplotypes based on single nucleotide polymorphisms in the putative promoter of MYB110 corresponded with its transcript levels and plant height in response to Pi availability. Thus, fine-tuning MYB110 expression may be a potent strategy for further increasing the yield of Green Revolution cereal crop varieties.


Asunto(s)
Grano Comestible , Oryza , Grano Comestible/genética , Oryza/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Productos Agrícolas , Fosfatos/metabolismo
11.
Proc Natl Acad Sci U S A ; 121(7): e2315688121, 2024 Feb 13.
Artículo en Inglés | MEDLINE | ID: mdl-38315857

RESUMEN

Integrating reactive radicals into membranes that resemble biological membranes has always been a pursuit for simultaneous organics degradation and water filtration. In this research, we discovered that a radical polymer (RP) that can directly trigger the oxidative degradation of sulfamethozaxole (SMX). Mechanistic studies by experiment and density functional theory simulations revealed that peroxyl radicals are the reactive species, and the radicals could be regenerated in the presence of O2. Furthermore, an interpenetrating RP network membrane consisting of polyvinyl alcohol and the RP was fabricated to demonstrate the simultaneous filtration of large molecules in the model wastewater stream and the degradation of ~ 85% of SMX with a steady permeation flux. This study offers valuable insights into the mechanism of RP-triggered advanced oxidation processes and provides an energy-efficient solution for the degradation of organic compounds and water filtration in wastewater treatment.

12.
Proc Natl Acad Sci U S A ; 121(19): e2322934121, 2024 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-38701119

RESUMEN

EPH receptors (EPHs), the largest family of tyrosine kinases, phosphorylate downstream substrates upon binding of ephrin cell surface-associated ligands. In a large cohort of endometriotic lesions from individuals with endometriosis, we found that EPHA2 and EPHA4 expressions are increased in endometriotic lesions relative to normal eutopic endometrium. Because signaling through EPHs is associated with increased cell migration and invasion, we hypothesized that chemical inhibition of EPHA2/4 could have therapeutic value. We screened DNA-encoded chemical libraries (DECL) to rapidly identify EPHA2/4 kinase inhibitors. Hit compound, CDD-2693, exhibited picomolar/nanomolar kinase activity against EPHA2 (Ki: 4.0 nM) and EPHA4 (Ki: 0.81 nM). Kinome profiling revealed that CDD-2693 bound to most EPH family and SRC family kinases. Using NanoBRET target engagement assays, CDD-2693 had nanomolar activity versus EPHA2 (IC50: 461 nM) and EPHA4 (IC50: 40 nM) but was a micromolar inhibitor of SRC, YES, and FGR. Chemical optimization produced CDD-3167, having picomolar biochemical activity toward EPHA2 (Ki: 0.13 nM) and EPHA4 (Ki: 0.38 nM) with excellent cell-based potency EPHA2 (IC50: 8.0 nM) and EPHA4 (IC50: 2.3 nM). Moreover, CDD-3167 maintained superior off-target cellular selectivity. In 12Z endometriotic epithelial cells, CDD-2693 and CDD-3167 significantly decreased EFNA5 (ligand) induced phosphorylation of EPHA2/4, decreased 12Z cell viability, and decreased IL-1ß-mediated expression of prostaglandin synthase 2 (PTGS2). CDD-2693 and CDD-3167 decreased expansion of primary endometrial epithelial organoids from patients with endometriosis and decreased Ewing's sarcoma viability. Thus, using DECL, we identified potent pan-EPH inhibitors that show specificity and activity in cellular models of endometriosis and cancer.


Asunto(s)
Inhibidores de Proteínas Quinasas , Humanos , Femenino , Inhibidores de Proteínas Quinasas/farmacología , Inhibidores de Proteínas Quinasas/química , Endometriosis/tratamiento farmacológico , Endometriosis/metabolismo , Endometriosis/patología , ADN/metabolismo , Receptores de la Familia Eph/metabolismo , Receptores de la Familia Eph/antagonistas & inhibidores , Receptor EphA2/metabolismo , Receptor EphA2/antagonistas & inhibidores , Bibliotecas de Moléculas Pequeñas/farmacología , Bibliotecas de Moléculas Pequeñas/química , Movimiento Celular/efectos de los fármacos
13.
Genome Res ; 33(10): 1690-1707, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37884341

RESUMEN

The rumen undergoes developmental changes during maturation. To characterize this understudied dynamic process, we profiled single-cell transcriptomes of about 308,000 cells from the rumen tissues of sheep and goats at 17 time points. We built comprehensive transcriptome and metagenome atlases from early embryonic to rumination stages, and recapitulated histomorphometric and transcriptional features of the rumen, revealing key transitional signatures associated with the development of ruminal cells, microbiota, and core transcriptional regulatory networks. In addition, we identified and validated potential cross-talk between host cells and microbiomes and revealed their roles in modulating the spatiotemporal expression of key genes in ruminal cells. Cross-species analyses revealed convergent developmental patterns of cellular heterogeneity, gene expression, and cell-cell and microbiome-cell interactions. Finally, we uncovered how the interactions can act upon the symbiotic rumen system to modify the processes of fermentation, fiber digestion, and immune defense. These results significantly enhance understanding of the genetic basis of the unique roles of rumen.


Asunto(s)
Metagenoma , Microbiota , Ovinos/genética , Animales , Transcriptoma , Rumen , Rumiantes/genética
14.
Brief Bioinform ; 25(3)2024 Mar 27.
Artículo en Inglés | MEDLINE | ID: mdl-38701418

RESUMEN

Coverage quantification is required in many sequencing datasets within the field of genomics research. However, most existing tools fail to provide comprehensive statistical results and exhibit limited performance gains from multithreading. Here, we present PanDepth, an ultra-fast and efficient tool for calculating coverage and depth from sequencing alignments. PanDepth outperforms other tools in computation time and memory efficiency for both BAM and CRAM-format alignment files from sequencing data, regardless of read length. It employs chromosome parallel computation and optimized data structures, resulting in ultrafast computation speeds and memory efficiency. It accepts sorted or unsorted BAM and CRAM-format alignment files as well as GTF, GFF and BED-formatted interval files or a specific window size. When provided with a reference genome sequence and the option to enable GC content calculation, PanDepth includes GC content statistics, enhancing the accuracy and reliability of copy number variation analysis. Overall, PanDepth is a powerful tool that accelerates scientific discovery in genomics research.


Asunto(s)
Genómica , Programas Informáticos , Genómica/métodos , Humanos , Análisis de Secuencia de ADN/métodos , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Composición de Base , Variaciones en el Número de Copia de ADN , Biología Computacional/métodos , Algoritmos , Alineación de Secuencia/métodos
15.
Brief Bioinform ; 25(5)2024 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-39082649

RESUMEN

Systematic investigation of tumor-infiltrating immune (TII) cells is important to the development of immunotherapies, and the clinical response prediction in cancers. There exists complex transcriptional regulation within TII cells, and different immune cell types display specific regulation patterns. To dissect transcriptional regulation in TII cells, we first integrated the gene expression profiles from single-cell datasets, and proposed a computational pipeline to identify TII cell type-specific transcription factor (TF) mediated activity immune modules (TF-AIMs). Our analysis revealed key TFs, such as BACH2 and NFKB1 play important roles in B and NK cells, respectively. We also found some of these TF-AIMs may contribute to tumor pathogenesis. Based on TII cell type-specific TF-AIMs, we identified eight CD8+ T cell subtypes. In particular, we found the PD1 + CD8+ T cell subset and its specific TF-AIMs associated with immunotherapy response. Furthermore, the TII cell type-specific TF-AIMs displayed the potential to be used as predictive markers for immunotherapy response of cancer patients. At the pan-cancer level, we also identified and characterized six molecular subtypes across 9680 samples based on the activation status of TII cell type-specific TF-AIMs. Finally, we constructed a user-friendly web interface CellTF-AIMs (http://bio-bigdata.hrbmu.edu.cn/CellTF-AIMs/) for exploring transcriptional regulatory pattern in various TII cell types. Our study provides valuable implications and a rich resource for understanding the mechanisms involved in cancer microenvironment and immunotherapy.


Asunto(s)
Inmunoterapia , Neoplasias , Factores de Transcripción , Humanos , Neoplasias/inmunología , Neoplasias/genética , Neoplasias/terapia , Neoplasias/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/metabolismo , Regulación Neoplásica de la Expresión Génica , Linfocitos Infiltrantes de Tumor/inmunología , Linfocitos Infiltrantes de Tumor/metabolismo , Biología Computacional/métodos
16.
Mol Cell ; 70(3): 395-407.e4, 2018 05 03.
Artículo en Inglés | MEDLINE | ID: mdl-29727616

RESUMEN

Telomeres and telomere-binding proteins form complex secondary nucleoprotein structures that are critical for genome integrity but can present serious challenges during telomere DNA replication. It remains unclear how telomere replication stress is resolved during S phase. Here, we show that the BUB3-BUB1 complex, a component in spindle assembly checkpoint, binds to telomeres during S phase and promotes telomere DNA replication. Loss of the BUB3-BUB1 complex results in telomere replication defects, including fragile and shortened telomeres. We also demonstrate that the telomere-binding ability of BUB3 and kinase activity of BUB1 are indispensable to BUB3-BUB1 function at telomeres. TRF2 targets BUB1-BUB3 to telomeres, and BUB1 can directly phosphorylate TRF1 and promote TRF1 recruitment of BLM helicase to overcome replication stress. Our findings have uncovered previously unknown roles for the BUB3-BUB1 complex in S phase and shed light on how proteins from diverse pathways function coordinately to ensure proper telomere replication and maintenance.


Asunto(s)
Proteínas de Ciclo Celular/genética , Replicación del ADN/genética , Proteínas de Unión a Poli-ADP-Ribosa/genética , Proteínas Serina-Treonina Quinasas/genética , Telómero/genética , Línea Celular , Línea Celular Tumoral , ADN Helicasas/genética , Células HEK293 , Células HeLa , Humanos , Puntos de Control de la Fase M del Ciclo Celular/genética , Fase S/genética , Huso Acromático/genética , Proteínas de Unión a Telómeros/genética
17.
Nucleic Acids Res ; 52(11): e50, 2024 Jun 24.
Artículo en Inglés | MEDLINE | ID: mdl-38797520

RESUMEN

Whole-genome bisulfite sequencing (BS-Seq) measures cytosine methylation changes at single-base resolution and can be used to profile cell-free DNA (cfDNA). In plasma, ultrashort single-stranded cfDNA (uscfDNA, ∼50 nt) has been identified together with 167 bp double-stranded mononucleosomal cell-free DNA (mncfDNA). However, the methylation profile of uscfDNA has not been described. Conventional BS-Seq workflows may not be helpful because bisulfite conversion degrades larger DNA into smaller fragments, leading to erroneous categorization as uscfDNA. We describe the '5mCAdpBS-Seq' workflow in which pre-methylated 5mC (5-methylcytosine) single-stranded adapters are ligated to heat-denatured cfDNA before bisulfite conversion. This method retains only DNA fragments that are unaltered by bisulfite treatment, resulting in less biased uscfDNA methylation analysis. Using 5mCAdpBS-Seq, uscfDNA had lower levels of DNA methylation (∼15%) compared to mncfDNA and was enriched in promoters and CpG islands. Hypomethylated uscfDNA fragments were enriched in upstream transcription start sites (TSSs), and the intensity of enrichment was correlated with expressed genes of hemopoietic cells. Using tissue-of-origin deconvolution, we inferred that uscfDNA is derived primarily from eosinophils, neutrophils, and monocytes. As proof-of-principle, we show that characteristics of the methylation profile of uscfDNA can distinguish non-small cell lung carcinoma from non-cancer samples. The 5mCAdpBS-Seq workflow is recommended for any cfDNA methylation-based investigations.


Asunto(s)
5-Metilcitosina , Ácidos Nucleicos Libres de Células , Islas de CpG , Metilación de ADN , ADN de Cadena Simple , Humanos , Ácidos Nucleicos Libres de Células/sangre , Ácidos Nucleicos Libres de Células/genética , ADN de Cadena Simple/metabolismo , ADN de Cadena Simple/genética , ADN de Cadena Simple/sangre , 5-Metilcitosina/metabolismo , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/sangre , Sulfitos/química , Regiones Promotoras Genéticas , Análisis de Secuencia de ADN/métodos , Secuenciación Completa del Genoma/métodos
18.
Proc Natl Acad Sci U S A ; 120(44): e2306086120, 2023 Oct 31.
Artículo en Inglés | MEDLINE | ID: mdl-37883433

RESUMEN

Munc13-1 is essential for vesicle docking and fusion at the active zone of synapses. Here, we report that Munc13-1 self-assembles into molecular clusters within diacylglycerol-rich microdomains present in phospholipid bilayers. Although the copy number of Munc13-1 molecules in these clusters has a broad distribution, a systematic Poisson analysis shows that this is most likely the result of two molecular species: monomers and mainly hexameric oligomers. Each oligomer is able to capture one vesicle independently. Hexamers have also been observed in crystals of Munc13-1 that form between opposed phospholipid bilayers [K. Grushin, R. V. Kalyana Sundaram, C. V. Sindelar, J. E. Rothman, Proc. Natl. Acad. Sci. U.S.A. 119, e2121259119 (2022)]. Mutations targeting the contacts stabilizing the crystallographic hexagons also disrupt the isolated hexamers, suggesting they are identical. Additionally, these mutations also convert vesicle binding from a cooperative to progressive mode. Our study provides an independent approach showing that Munc13-1 can form mainly hexamers on lipid bilayers each capable of vesicle capture.


Asunto(s)
Diglicéridos , Proteínas SNARE , Proteínas SNARE/metabolismo , Diglicéridos/metabolismo , Sinapsis/metabolismo , Chaperonas Moleculares/metabolismo , Fosfolípidos/metabolismo
19.
Proc Natl Acad Sci U S A ; 120(38): e2305575120, 2023 09 19.
Artículo en Inglés | MEDLINE | ID: mdl-37695909

RESUMEN

Animal cytoplasmic fatty acid synthase (FAS) represents a unique family of enzymes that are classically thought to be most closely related to fungal polyketide synthase (PKS). Recently, a widespread family of animal lipid metabolic enzymes has been described that bridges the gap between these two ubiquitous and important enzyme classes: the animal FAS-like PKSs (AFPKs). Although very similar in sequence to FAS enzymes that produce saturated lipids widely found in animals, AFPKs instead produce structurally diverse compounds that resemble bioactive polyketides. Little is known about the factors that bridge lipid and polyketide synthesis in the animals. Here, we describe the function of EcPKS2 from Elysia chlorotica, which synthesizes a complex polypropionate natural product found in this mollusc. EcPKS2 starter unit promiscuity potentially explains the high diversity of polyketides found in and among molluscan species. Biochemical comparison of EcPKS2 with the previously described EcPKS1 reveals molecular principles governing substrate selectivity that should apply to related enzymes encoded within the genomes of photosynthetic gastropods. Hybridization experiments combining EcPKS1 and EcPKS2 demonstrate the interactions between the ketoreductase and ketosynthase domains in governing the product outcomes. Overall, these findings enable an understanding of the molecular principles of structural diversity underlying the many molluscan polyketides likely produced by the diverse AFPK enzyme family.


Asunto(s)
Productos Biológicos , Gastrópodos , Policétidos , Animales , Sintasas Poliquetidas/genética , Ácido Graso Sintasas , Lípidos
20.
Proc Natl Acad Sci U S A ; 120(34): e2309516120, 2023 08 22.
Artículo en Inglés | MEDLINE | ID: mdl-37590407

RESUMEN

Here, we introduce the full functional reconstitution of genetically validated core protein machinery (SNAREs, Munc13, Munc18, Synaptotagmin, and Complexin) for synaptic vesicle priming and release in a geometry that enables detailed characterization of the fate of docked vesicles both before and after release is triggered with Ca2+. Using this setup, we identify new roles for diacylglycerol (DAG) in regulating vesicle priming and Ca2+-triggered release involving the SNARE assembly chaperone Munc13. We find that low concentrations of DAG profoundly accelerate the rate of Ca2+-dependent release, and high concentrations reduce clamping and permit extensive spontaneous release. As expected, DAG also increases the number of docked, release-ready vesicles. Dynamic single-molecule imaging of Complexin binding to release-ready vesicles directly establishes that DAG accelerates the rate of SNAREpin assembly mediated by chaperones, Munc13 and Munc18. The selective effects of physiologically validated mutations confirmed that the Munc18-Syntaxin-VAMP2 "template" complex is a functional intermediate in the production of primed, release-ready vesicles, which requires the coordinated action of Munc13 and Munc18.


Asunto(s)
Diglicéridos , Vesículas Sinápticas , Humanos , Exocitosis , Transmisión Sináptica , Sinaptotagminas , Vesícula
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