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1.
Cell ; 187(1): 184-203.e28, 2024 01 04.
Artículo en Inglés | MEDLINE | ID: mdl-38181741

RESUMEN

We performed comprehensive proteogenomic characterization of small cell lung cancer (SCLC) using paired tumors and adjacent lung tissues from 112 treatment-naive patients who underwent surgical resection. Integrated multi-omics analysis illustrated cancer biology downstream of genetic aberrations and highlighted oncogenic roles of FAT1 mutation, RB1 deletion, and chromosome 5q loss. Two prognostic biomarkers, HMGB3 and CASP10, were identified. Overexpression of HMGB3 promoted SCLC cell migration via transcriptional regulation of cell junction-related genes. Immune landscape characterization revealed an association between ZFHX3 mutation and high immune infiltration and underscored a potential immunosuppressive role of elevated DNA damage response activity via inhibition of the cGAS-STING pathway. Multi-omics clustering identified four subtypes with subtype-specific therapeutic vulnerabilities. Cell line and patient-derived xenograft-based drug tests validated the specific therapeutic responses predicted by multi-omics subtyping. This study provides a valuable resource as well as insights to better understand SCLC biology and improve clinical practice.


Asunto(s)
Neoplasias Pulmonares , Proteogenómica , Carcinoma Pulmonar de Células Pequeñas , Humanos , Línea Celular , Neoplasias Pulmonares/química , Neoplasias Pulmonares/genética , Carcinoma Pulmonar de Células Pequeñas/química , Carcinoma Pulmonar de Células Pequeñas/genética , Xenoinjertos , Biomarcadores de Tumor/análisis
2.
Cell ; 186(23): 5114-5134.e27, 2023 11 09.
Artículo en Inglés | MEDLINE | ID: mdl-37875108

RESUMEN

Human inherited disorders of interferon-gamma (IFN-γ) immunity underlie severe mycobacterial diseases. We report X-linked recessive MCTS1 deficiency in men with mycobacterial disease from kindreds of different ancestries (from China, Finland, Iran, and Saudi Arabia). Complete deficiency of this translation re-initiation factor impairs the translation of a subset of proteins, including the kinase JAK2 in all cell types tested, including T lymphocytes and phagocytes. JAK2 expression is sufficiently low to impair cellular responses to interleukin-23 (IL-23) and partially IL-12, but not other JAK2-dependent cytokines. Defective responses to IL-23 preferentially impair the production of IFN-γ by innate-like adaptive mucosal-associated invariant T cells (MAIT) and γδ T lymphocytes upon mycobacterial challenge. Surprisingly, the lack of MCTS1-dependent translation re-initiation and ribosome recycling seems to be otherwise physiologically redundant in these patients. These findings suggest that X-linked recessive human MCTS1 deficiency underlies isolated mycobacterial disease by impairing JAK2 translation in innate-like adaptive T lymphocytes, thereby impairing the IL-23-dependent induction of IFN-γ.


Asunto(s)
Interferón gamma , Janus Quinasa 2 , Infecciones por Mycobacterium , Humanos , Masculino , Proteínas de Ciclo Celular/metabolismo , Interferón gamma/inmunología , Interleucina-12 , Interleucina-23 , Janus Quinasa 2/metabolismo , Mycobacterium/fisiología , Infecciones por Mycobacterium/inmunología , Infecciones por Mycobacterium/metabolismo , Proteínas Oncogénicas/metabolismo
3.
Cell ; 186(3): 621-645.e33, 2023 02 02.
Artículo en Inglés | MEDLINE | ID: mdl-36736301

RESUMEN

Inborn errors of human IFN-γ-dependent macrophagic immunity underlie mycobacterial diseases, whereas inborn errors of IFN-α/ß-dependent intrinsic immunity underlie viral diseases. Both types of IFNs induce the transcription factor IRF1. We describe unrelated children with inherited complete IRF1 deficiency and early-onset, multiple, life-threatening diseases caused by weakly virulent mycobacteria and related intramacrophagic pathogens. These children have no history of severe viral disease, despite exposure to many viruses, including SARS-CoV-2, which is life-threatening in individuals with impaired IFN-α/ß immunity. In leukocytes or fibroblasts stimulated in vitro, IRF1-dependent responses to IFN-γ are, both quantitatively and qualitatively, much stronger than those to IFN-α/ß. Moreover, IRF1-deficient mononuclear phagocytes do not control mycobacteria and related pathogens normally when stimulated with IFN-γ. By contrast, IFN-α/ß-dependent intrinsic immunity to nine viruses, including SARS-CoV-2, is almost normal in IRF1-deficient fibroblasts. Human IRF1 is essential for IFN-γ-dependent macrophagic immunity to mycobacteria, but largely redundant for IFN-α/ß-dependent antiviral immunity.


Asunto(s)
COVID-19 , Mycobacterium , Niño , Humanos , Interferón gamma , SARS-CoV-2 , Interferón-alfa , Factor 1 Regulador del Interferón
4.
Cell ; 185(25): 4811-4825.e17, 2022 Dec 08.
Artículo en Inglés | MEDLINE | ID: mdl-36423629

RESUMEN

Pediatric SARS-CoV-2 vaccines are needed that elicit immunity directly in the airways as well as systemically. Building on pediatric parainfluenza virus vaccines in clinical development, we generated a live-attenuated parainfluenza-virus-vectored vaccine candidate expressing SARS-CoV-2 prefusion-stabilized spike (S) protein (B/HPIV3/S-6P) and evaluated its immunogenicity and protective efficacy in rhesus macaques. A single intranasal/intratracheal dose of B/HPIV3/S-6P induced strong S-specific airway mucosal immunoglobulin A (IgA) and IgG responses. High levels of S-specific antibodies were also induced in serum, which efficiently neutralized SARS-CoV-2 variants of concern of alpha, beta, and delta lineages, while their ability to neutralize Omicron sub-lineages was lower. Furthermore, B/HPIV3/S-6P induced robust systemic and pulmonary S-specific CD4+ and CD8+ T cell responses, including tissue-resident memory cells in the lungs. Following challenge, SARS-CoV-2 replication was undetectable in airways and lung tissues of immunized macaques. B/HPIV3/S-6P will be evaluated clinically as pediatric intranasal SARS-CoV-2/parainfluenza virus type 3 vaccine.


Asunto(s)
Vacunas contra la COVID-19 , COVID-19 , Animales , Humanos , Anticuerpos Neutralizantes , Anticuerpos Antivirales , Macaca mulatta , COVID-19/prevención & control , SARS-CoV-2/genética
5.
Cell ; 183(7): 1826-1847.e31, 2020 12 23.
Artículo en Inglés | MEDLINE | ID: mdl-33296702

RESUMEN

Inborn errors of human interferon gamma (IFN-γ) immunity underlie mycobacterial disease. We report a patient with mycobacterial disease due to inherited deficiency of the transcription factor T-bet. The patient has extremely low counts of circulating Mycobacterium-reactive natural killer (NK), invariant NKT (iNKT), mucosal-associated invariant T (MAIT), and Vδ2+ γδ T lymphocytes, and of Mycobacterium-non reactive classic TH1 lymphocytes, with the residual populations of these cells also producing abnormally small amounts of IFN-γ. Other lymphocyte subsets develop normally but produce low levels of IFN-γ, with the exception of CD8+ αß T and non-classic CD4+ αß TH1∗ lymphocytes, which produce IFN-γ normally in response to mycobacterial antigens. Human T-bet deficiency thus underlies mycobacterial disease by preventing the development of innate (NK) and innate-like adaptive lymphocytes (iNKT, MAIT, and Vδ2+ γδ T cells) and IFN-γ production by them, with mycobacterium-specific, IFN-γ-producing, purely adaptive CD8+ αß T, and CD4+ αß TH1∗ cells unable to compensate for this deficit.


Asunto(s)
Inmunidad Adaptativa , Inmunidad Innata , Interferón gamma/inmunología , Mycobacterium/inmunología , Proteínas de Dominio T Box/metabolismo , Secuencia de Aminoácidos , Secuencia de Bases , Linaje de la Célula , Preescolar , Cromatina/metabolismo , Islas de CpG/genética , Metilación de ADN/genética , Células Dendríticas/metabolismo , Epigénesis Genética , Femenino , Homocigoto , Humanos , Mutación INDEL/genética , Lactante , Interferón gamma/metabolismo , Células Asesinas Naturales/citología , Células Asesinas Naturales/metabolismo , Mutación con Pérdida de Función/genética , Masculino , Infecciones por Mycobacterium/genética , Infecciones por Mycobacterium/inmunología , Infecciones por Mycobacterium/microbiología , Linaje , Proteínas de Dominio T Box/química , Proteínas de Dominio T Box/deficiencia , Proteínas de Dominio T Box/genética , Linfocitos T Colaboradores-Inductores/inmunología , Transcriptoma/genética
6.
Nat Immunol ; 23(5): 692-704, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35484407

RESUMEN

The NLRP3 inflammasome is linked to sterile and pathogen-dependent inflammation, and its dysregulation underlies many chronic diseases. Mitochondria have been implicated as regulators of the NLRP3 inflammasome through several mechanisms including generation of mitochondrial reactive oxygen species (ROS). Here, we report that mitochondrial electron transport chain (ETC) complex I, II, III and V inhibitors all prevent NLRP3 inflammasome activation. Ectopic expression of Saccharomyces cerevisiae NADH dehydrogenase (NDI1) or Ciona intestinalis alternative oxidase, which can complement the functional loss of mitochondrial complex I or III, respectively, without generation of ROS, rescued NLRP3 inflammasome activation in the absence of endogenous mitochondrial complex I or complex III function. Metabolomics revealed phosphocreatine (PCr), which can sustain ATP levels, as a common metabolite that is diminished by mitochondrial ETC inhibitors. PCr depletion decreased ATP levels and NLRP3 inflammasome activation. Thus, the mitochondrial ETC sustains NLRP3 inflammasome activation through PCr-dependent generation of ATP, but via a ROS-independent mechanism.


Asunto(s)
Inflamasomas , Proteína con Dominio Pirina 3 de la Familia NLR , Adenosina Trifosfato/metabolismo , Transporte de Electrón , Inflamasomas/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/genética , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Especies Reactivas de Oxígeno/metabolismo
7.
Cell ; 174(6): 1450-1464.e23, 2018 09 06.
Artículo en Inglés | MEDLINE | ID: mdl-30100184

RESUMEN

Synapses are fundamental units of communication in the brain. The prototypical synapse-organizing complex neurexin-neuroligin mediates synapse development and function and is central to a shared genetic risk pathway in autism and schizophrenia. Neurexin's role in synapse development is thought to be mediated purely by its protein domains, but we reveal a requirement for a rare glycan modification. Mice lacking heparan sulfate (HS) on neurexin-1 show reduced survival, as well as structural and functional deficits at central synapses. HS directly binds postsynaptic partners neuroligins and LRRTMs, revealing a dual binding mode involving intrinsic glycan and protein domains for canonical synapse-organizing complexes. Neurexin HS chains also bind novel ligands, potentially expanding the neurexin interactome to hundreds of HS-binding proteins. Because HS structure is heterogeneous, our findings indicate an additional dimension to neurexin diversity, provide a molecular basis for fine-tuning synaptic function, and open therapeutic directions targeting glycan-binding motifs critical for brain development.


Asunto(s)
Heparitina Sulfato/metabolismo , Moléculas de Adhesión de Célula Nerviosa/metabolismo , Sinapsis/metabolismo , Secuencia de Aminoácidos , Animales , Proteínas de Unión al Calcio , Moléculas de Adhesión Celular Neuronal/antagonistas & inhibidores , Moléculas de Adhesión Celular Neuronal/genética , Moléculas de Adhesión Celular Neuronal/metabolismo , Drosophila , Proteínas de Drosophila/antagonistas & inhibidores , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Femenino , Glicopéptidos/análisis , Heparitina Sulfato/química , Humanos , Proteínas de la Membrana , Ratones , Ratones Endogámicos C57BL , Proteínas del Tejido Nervioso , Moléculas de Adhesión de Célula Nerviosa/antagonistas & inhibidores , Moléculas de Adhesión de Célula Nerviosa/genética , Neuronas/citología , Neuronas/metabolismo , Unión Proteica , Interferencia de ARN , ARN Interferente Pequeño/metabolismo , Ratas , Alineación de Secuencia
8.
Cell ; 174(3): 576-589.e18, 2018 07 26.
Artículo en Inglés | MEDLINE | ID: mdl-30033361

RESUMEN

Genome-wide association studies (GWAS) have identified rs11672691 at 19q13 associated with aggressive prostate cancer (PCa). Here, we independently confirmed the finding in a cohort of 2,738 PCa patients and discovered the biological mechanism underlying this association. We found an association of the aggressive PCa-associated allele G of rs11672691 with elevated transcript levels of two biologically plausible candidate genes, PCAT19 and CEACAM21, implicated in PCa cell growth and tumor progression. Mechanistically, rs11672691 resides in an enhancer element and alters the binding site of HOXA2, a novel oncogenic transcription factor with prognostic potential in PCa. Remarkably, CRISPR/Cas9-mediated single-nucleotide editing showed the direct effect of rs11672691 on PCAT19 and CEACAM21 expression and PCa cellular aggressive phenotype. Clinical data demonstrated synergistic effects of rs11672691 genotype and PCAT19/CEACAM21 gene expression on PCa prognosis. These results provide a plausible mechanism for rs11672691 associated with aggressive PCa and thus lay the ground work for translating this finding to the clinic.


Asunto(s)
Neoplasias de la Próstata/genética , ARN Largo no Codificante/genética , ARN no Traducido/genética , Adulto , Alelos , Línea Celular Tumoral , Cromosomas Humanos Par 19/genética , Estudios de Cohortes , Regulación Neoplásica de la Expresión Génica/genética , Frecuencia de los Genes/genética , Predisposición Genética a la Enfermedad/genética , Estudio de Asociación del Genoma Completo , Genotipo , Proteínas de Homeodominio , Humanos , Masculino , Persona de Mediana Edad , Polimorfismo de Nucleótido Simple/genética , Pronóstico
9.
Immunity ; 56(11): 2523-2541.e8, 2023 Nov 14.
Artículo en Inglés | MEDLINE | ID: mdl-37924812

RESUMEN

Gasdermin D (GSDMD)-activated inflammatory cell death (pyroptosis) causes mitochondrial damage, but its underlying mechanism and functional consequences are largely unknown. Here, we show that the N-terminal pore-forming GSDMD fragment (GSDMD-NT) rapidly damaged both inner and outer mitochondrial membranes (OMMs) leading to reduced mitochondrial numbers, mitophagy, ROS, loss of transmembrane potential, attenuated oxidative phosphorylation (OXPHOS), and release of mitochondrial proteins and DNA from the matrix and intermembrane space. Mitochondrial damage occurred as soon as GSDMD was cleaved prior to plasma membrane damage. Mitochondrial damage was independent of the B-cell lymphoma 2 family and depended on GSDMD-NT binding to cardiolipin. Canonical and noncanonical inflammasome activation of mitochondrial damage, pyroptosis, and inflammatory cytokine release were suppressed by genetic ablation of cardiolipin synthase (Crls1) or the scramblase (Plscr3) that transfers cardiolipin to the OMM. Phospholipid scramblase-3 (PLSCR3) deficiency in a tumor compromised pyroptosis-triggered anti-tumor immunity. Thus, mitochondrial damage plays a critical role in pyroptosis.


Asunto(s)
Gasderminas , Piroptosis , Proteínas de Neoplasias/metabolismo , Cardiolipinas/metabolismo , Péptidos y Proteínas de Señalización Intracelular/genética , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Inflamasomas/metabolismo
10.
Cell ; 161(4): 893-906, 2015 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-25936838

RESUMEN

DNA N(6)-methyladenine (6mA) modification is commonly found in microbial genomes and plays important functions in regulating numerous biological processes in bacteria. However, whether 6mA occurs and what its potential roles are in higher-eukaryote cells remain unknown. Here, we show that 6mA is present in Drosophila genome and that the 6mA modification is dynamic and is regulated by the Drosophila Tet homolog, DNA 6mA demethylase (DMAD), during embryogenesis. Importantly, our biochemical assays demonstrate that DMAD directly catalyzes 6mA demethylation in vitro. Further genetic and sequencing analyses reveal that DMAD is essential for development and that DMAD removes 6mA primarily from transposon regions, which correlates with transposon suppression in Drosophila ovary. Collectively, we uncover a DNA modification in Drosophila and describe a potential role of the DMAD-6mA regulatory axis in controlling development in higher eukaryotes.


Asunto(s)
Adenina/análogos & derivados , Metilación de ADN , Drosophila/metabolismo , Adenina/metabolismo , Secuencia de Aminoácidos , Animales , Elementos Transponibles de ADN , Drosophila/embriología , Drosophila/enzimología , Femenino , Regulación del Desarrollo de la Expresión Génica , Datos de Secuencia Molecular , Ovario/metabolismo , Alineación de Secuencia , Metiltransferasa de ADN de Sitio Específico (Adenina Especifica)/metabolismo
11.
Nature ; 621(7979): 610-619, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37557913

RESUMEN

The proper regulation of transcription is essential for maintaining genome integrity and executing other downstream cellular functions1,2. Here we identify a stable association between the genome-stability regulator sensor of single-stranded DNA (SOSS)3 and the transcription regulator Integrator-PP2A (INTAC)4-6. Through SSB1-mediated recognition of single-stranded DNA, SOSS-INTAC stimulates promoter-proximal termination of transcription and attenuates R-loops associated with paused RNA polymerase II to prevent R-loop-induced genome instability. SOSS-INTAC-dependent attenuation of R-loops is enhanced by the ability of SSB1 to form liquid-like condensates. Deletion of NABP2 (encoding SSB1) or introduction of cancer-associated mutations into its intrinsically disordered region leads to a pervasive accumulation of R-loops, highlighting a genome surveillance function of SOSS-INTAC that enables timely termination of transcription at promoters to constrain R-loop accumulation and ensure genome stability.


Asunto(s)
Inestabilidad Genómica , Regiones Promotoras Genéticas , Estructuras R-Loop , Terminación de la Transcripción Genética , Humanos , ADN de Cadena Simple/metabolismo , Inestabilidad Genómica/genética , Mutación , Estructuras R-Loop/genética , ARN Polimerasa II/metabolismo , Regiones Promotoras Genéticas/genética , Genoma Humano , Proteínas de Unión al ADN/metabolismo
12.
Nature ; 615(7950): 56-61, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36859579

RESUMEN

Correlating atomic configurations-specifically, degree of disorder (DOD)-of an amorphous solid with properties is a long-standing riddle in materials science and condensed matter physics, owing to difficulties in determining precise atomic positions in 3D structures1-5. To this end, 2D systems provide insight to the puzzle by allowing straightforward imaging of all atoms6,7. Direct imaging of amorphous monolayer carbon (AMC) grown by laser-assisted depositions has resolved atomic configurations, supporting the modern crystallite view of vitreous solids over random network theory8. Nevertheless, a causal link between atomic-scale structures and macroscopic properties remains elusive. Here we report facile tuning of DOD and electrical conductivity in AMC films by varying growth temperatures. Specifically, the pyrolysis threshold temperature is the key to growing variable-range-hopping conductive AMC with medium-range order (MRO), whereas increasing the temperature by 25 °C results in AMC losing MRO and becoming electrically insulating, with an increase in sheet resistance of 109 times. Beyond visualizing highly distorted nanocrystallites embedded in a continuous random network, atomic-resolution electron microscopy shows the absence/presence of MRO and temperature-dependent densities of nanocrystallites, two order parameters proposed to fully describe DOD. Numerical calculations establish the conductivity diagram as a function of these two parameters, directly linking microstructures to electrical properties. Our work represents an important step towards understanding the structure-property relationship of amorphous materials at the fundamental level and paves the way to electronic devices using 2D amorphous materials.

13.
Nature ; 623(7988): 803-813, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37938781

RESUMEN

Patients with autoimmune polyendocrinopathy syndrome type 1 (APS-1) caused by autosomal recessive AIRE deficiency produce autoantibodies that neutralize type I interferons (IFNs)1,2, conferring a predisposition to life-threatening COVID-19 pneumonia3. Here we report that patients with autosomal recessive NIK or RELB deficiency, or a specific type of autosomal-dominant NF-κB2 deficiency, also have neutralizing autoantibodies against type I IFNs and are at higher risk of getting life-threatening COVID-19 pneumonia. In patients with autosomal-dominant NF-κB2 deficiency, these autoantibodies are found only in individuals who are heterozygous for variants associated with both transcription (p52 activity) loss of function (LOF) due to impaired p100 processing to generate p52, and regulatory (IκBδ activity) gain of function (GOF) due to the accumulation of unprocessed p100, therefore increasing the inhibitory activity of IκBδ (hereafter, p52LOF/IκBδGOF). By contrast, neutralizing autoantibodies against type I IFNs are not found in individuals who are heterozygous for NFKB2 variants causing haploinsufficiency of p100 and p52 (hereafter, p52LOF/IκBδLOF) or gain-of-function of p52 (hereafter, p52GOF/IκBδLOF). In contrast to patients with APS-1, patients with disorders of NIK, RELB or NF-κB2 have very few tissue-specific autoantibodies. However, their thymuses have an abnormal structure, with few AIRE-expressing medullary thymic epithelial cells. Human inborn errors of the alternative NF-κB pathway impair the development of AIRE-expressing medullary thymic epithelial cells, thereby underlying the production of autoantibodies against type I IFNs and predisposition to viral diseases.


Asunto(s)
Autoanticuerpos , Predisposición Genética a la Enfermedad , Interferón Tipo I , FN-kappa B , Humanos , Autoanticuerpos/inmunología , COVID-19/genética , COVID-19/inmunología , Mutación con Ganancia de Función , Heterocigoto , Proteínas I-kappa B/deficiencia , Proteínas I-kappa B/genética , Interferón Tipo I/antagonistas & inhibidores , Interferón Tipo I/inmunología , Mutación con Pérdida de Función , FN-kappa B/deficiencia , FN-kappa B/genética , Subunidad p52 de NF-kappa B/deficiencia , Subunidad p52 de NF-kappa B/genética , Neumonía Viral/genética , Neumonía Viral/inmunología , Timo/anomalías , Timo/inmunología , Timo/patología , Células Epiteliales Tiroideas/metabolismo , Células Epiteliales Tiroideas/patología , Proteína AIRE , Quinasa de Factor Nuclear kappa B
14.
PLoS Biol ; 22(1): e3002375, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38236815

RESUMEN

Detecting imminent collisions is essential for survival. Here, we used high-resolution fMRI at 7 Tesla to investigate the role of attention and consciousness for detecting collision trajectory in human subcortical pathways. Healthy participants can precisely discriminate collision from near-miss trajectory of an approaching object, with pupil size change reflecting collision sensitivity. Subcortical pathways from the superior colliculus (SC) to the ventromedial pulvinar (vmPul) and ventral tegmental area (VTA) exhibited collision-sensitive responses even when participants were not paying attention to the looming stimuli. For hemianopic patients with unilateral lesions of the geniculostriate pathway, the ipsilesional SC and VTA showed significant activation to collision stimuli in their scotoma. Furthermore, stronger SC responses predicted better behavioral performance in collision detection even in the absence of awareness. Therefore, human tectofugal pathways could automatically detect collision trajectories without the observers' attention to and awareness of looming stimuli, supporting "blindsight" detection of impending visual threats.


Asunto(s)
Percepción de Movimiento , Pulvinar , Humanos , Percepción de Movimiento/fisiología , Colículos Superiores/fisiología , Imagen por Resonancia Magnética , Pulvinar/diagnóstico por imagen , Estimulación Luminosa , Vías Visuales/fisiología
15.
Proc Natl Acad Sci U S A ; 121(4): e2316724121, 2024 Jan 23.
Artículo en Inglés | MEDLINE | ID: mdl-38232284

RESUMEN

Photoelectrochemical (PEC) carbon dioxide (CO2) reduction (CO2R) holds the potential to reduce the costs of solar fuel production by integrating CO2 utilization and light harvesting within one integrated device. However, the CO2R selectivity on the photocathode is limited by the lack of catalytic active sites and competition with the hydrogen evolution reaction. On the other hand, serious parasitic light absorption occurs on the front-side-illuminated photocathode due to the poor light transmittance of CO2R cocatalyst films, resulting in extremely low photocurrent density at the CO2R equilibrium potential. This paper describes the design and fabrication of a photocathode consisting of crystal phase-modulated Ag nanocrystal cocatalysts integrated on illumination-reaction decoupled heterojunction silicon (Si) substrate for the selective and efficient conversion of CO2. Ag nanocrystals containing unconventional hexagonal close-packed phases accelerate the charge transfer process in CO2R reaction, exhibiting excellent catalytic performance. Heterojunction Si substrate decouples light absorption from the CO2R catalyst layer, preventing the parasitic light absorption. The obtained photocathode exhibits a carbon monoxide (CO) Faradaic efficiency (FE) higher than 90% in a wide potential range, with the maximum FE reaching up to 97.4% at -0.2 V vs. reversible hydrogen electrode. At the CO2/CO equilibrium potential, a CO partial photocurrent density of -2.7 mA cm-2 with a CO FE of 96.5% is achieved in 0.1 M KHCO3 electrolyte on this photocathode, surpassing the expensive benchmark Au-based PEC CO2R system.

16.
Proc Natl Acad Sci U S A ; 121(3): e2319335121, 2024 Jan 16.
Artículo en Inglés | MEDLINE | ID: mdl-38198526

RESUMEN

The phytohormone cytokinin has various roles in plant development, including meristem maintenance, vascular differentiation, leaf senescence, and regeneration. Prior investigations have revealed that cytokinin acts via a phosphorelay similar to the two-component system by which bacteria sense and respond to external stimuli. The eventual targets of this phosphorelay are type-B ARABIDOPSIS RESPONSE REGULATORS (B-ARRs), containing the conserved N-terminal receiver domain (RD), middle DNA binding domain (DBD), and C-terminal transactivation domain. While it has been established for two decades that the phosphoryl transfer from a specific histidyl residue in ARABIDOPSIS HIS PHOSPHOTRANSFER PROTEINS (AHPs) to an aspartyl residue in the RD of B-ARRs results in a rapid transcriptional response to cytokinin, the underlying molecular basis remains unclear. In this work, we determine the crystal structures of the RD-DBD of ARR1 (ARR1RD-DBD) as well as the ARR1DBD-DNA complex from Arabidopsis. Analyses of the ARR1DBD-DNA complex have revealed the structural basis for sequence-specific recognition of the GAT trinucleotide by ARR1. In particular, comparing the ARR1RD-DBD and ARR1DBD-DNA structures reveals that unphosphorylated ARR1RD-DBD exists in a closed conformation with extensive contacts between the RD and DBD. In vitro and vivo functional assays have further suggested that phosphorylation of the RD weakens its interaction with DBD, subsequently permits the DNA binding capacity of DBD, and promotes the transcriptional activity of ARR1. Our findings thus provide mechanistic insights into phosphorelay activation of gene transcription in response to cytokinin.


Asunto(s)
Arabidopsis , Citocininas , Activación Transcripcional , Arabidopsis/genética , Reguladores del Crecimiento de las Plantas , ADN
17.
Proc Natl Acad Sci U S A ; 121(3): e2308994121, 2024 Jan 16.
Artículo en Inglés | MEDLINE | ID: mdl-38190536

RESUMEN

The relationship between initial Homo sapiens dispersal from Africa to East Asia and the orbitally paced evolution of the Asian summer monsoon (ASM)-currently the largest monsoon system-remains underexplored due to lack of coordinated synthesis of both Asian paleoanthropological and paleoclimatic data. Here, we investigate orbital-scale ASM dynamics during the last 280 thousand years (kyr) and their likely influences on early H. sapiens dispersal to East Asia, through a unique integration of i) new centennial-resolution ASM records from the Chinese Loess Plateau, ii) model-based East Asian hydroclimatic reconstructions, iii) paleoanthropological data compilations, and iv) global H. sapiens habitat suitability simulations. Our combined proxy- and model-based reconstructions suggest that ASM precipitation responded to a combination of Northern Hemisphere ice volume, greenhouse gas, and regional summer insolation forcing, with cooccurring primary orbital cycles of ~100-kyr, 41-kyr, and ~20-kyr. Between ~125 and 70 kyr ago, summer monsoon rains and temperatures increased in vast areas across Asia. This episode coincides with the earliest H. sapiens fossil occurrence at multiple localities in East Asia. Following the transcontinental increase in simulated habitat suitability, we suggest that ASM strengthening together with Southeast African climate deterioration may have promoted the initial H. sapiens dispersal from their African homeland to remote East Asia during the last interglacial.


Asunto(s)
Pueblo Asiatico , Migración Humana , Tiempo (Meteorología) , Humanos , África , Asia , Asia Oriental
18.
Plant Cell ; 35(3): 994-1012, 2023 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-36560915

RESUMEN

Species of the tribe Delphinieae (Ranunculaceae) have long been the focus of morphological, ecological, and evolutionary studies due to their highly specialized, nearly zygomorphic (bilaterally symmetrical) spiral flowers with nested petal and sepal spurs and reduced petals. The mechanisms underlying the development and evolution of Delphinieae flowers, however, remain unclear. Here, by conducting extensive phylogenetic, comparative transcriptomic, expression, and functional studies, we clarified the evolutionary histories, expression patterns, and functions of floral organ identity and symmetry genes in Delphinieae. We found that duplication and/or diversification of APETALA3-3 (AP3-3), AGAMOUS-LIKE6 (AGL6), CYCLOIDEA (CYC), and DIVARICATA (DIV) lineage genes was tightly associated with the origination of Delphinieae flowers. Specifically, an AGL6-lineage member (such as the Delphinium ajacis AGL6-1a) represses sepal spur formation and petal development in the lateral and ventral parts of the flower while determining petal identity redundantly with AGL6-1b. By contrast, two CYC2-like genes, CYC2b and CYC2a, define the dorsal and lateral-ventral identities of the flower, respectively, and form complex regulatory links with AP3-3, AGL6-1a, and DIV1. Therefore, duplication and diversification of floral symmetry genes, as well as co-option of the duplicated copies into the preexisting floral regulatory network, have been key for the origin of Delphinieae flowers.


Asunto(s)
Flores , Duplicación de Gen , Ranunculaceae , Flores/genética , Perfilación de la Expresión Génica , Regulación de la Expresión Génica de las Plantas/genética , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Ranunculaceae/genética
19.
Nat Chem Biol ; 20(4): 484-492, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37945893

RESUMEN

GPR101 is an orphan G protein-coupled receptor actively participating in energy homeostasis. Here we report the cryo-electron microscopy structure of GPR101 constitutively coupled to Gs heterotrimer, which reveals unique features of GPR101, including the interaction of extracellular loop 2 within the 7TM bundle, a hydrophobic chain packing-mediated activation mechanism and the structural basis of disease-related mutants. Importantly, a side pocket is identified in GPR101 that facilitates in silico screening to identify four small-molecule agonists, including AA-14. The structure of AA-14-GPR101-Gs provides direct evidence of the AA-14 binding at the side pocket. Functionally, AA-14 partially restores the functions of GH/IGF-1 axis and exhibits several rejuvenating effects in wild-type mice, which are abrogated in Gpr101-deficient mice. In summary, we provide a structural basis for the constitutive activity of GPR101. The structure-facilitated identification of GPR101 agonists and functional analysis suggest that targeting this orphan receptor has rejuvenating potential.


Asunto(s)
Receptores Acoplados a Proteínas G , Ratones , Animales , Microscopía por Crioelectrón , Receptores Acoplados a Proteínas G/metabolismo , Ligandos
20.
Nucleic Acids Res ; 52(D1): D1614-D1628, 2024 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-37953341

RESUMEN

Plants are unique with tremendous chemical diversity and metabolic complexity, which is highlighted by estimates that green plants collectively produce metabolites numbering in the millions. Plant metabolites play crucial roles in all aspects of plant biology, like growth, development, stress responses, etc. However, the lack of a reference metabolome for plants, and paucity of high-quality standard compound spectral libraries and related analytical tools, have hindered the discovery and functional study of phytochemicals in plants. Here, by leveraging an advanced LC-MS platform, we generated untargeted mass spectral data from >150 plant species collected across the five major phyla. Using a self-developed computation protocol, we constructed reference metabolome for 153 plant species. A 'Reference Metabolome Database for Plants' (RefMetaPlant) was built to encompass the reference metabolome, integrated standard compound mass spectral libraries for annotation, and related query and analytical tools like 'LC-MS/MS Query', 'RefMetaBlast' and 'CompoundLibBlast' for searches and profiling of plant metabolome and metabolite identification. Analogous to a reference genome in genomic research, RefMetaPlant provides a powerful platform to support plant genome-scale metabolite analysis to promote knowledge/data sharing and collaboration in the field of metabolomics. RefMetaPlant is freely available at https://www.biosino.org/RefMetaDB/.


Asunto(s)
Bases de Datos Factuales , Metaboloma , Cromatografía Liquida , Metaboloma/genética , Metabolómica/métodos , Plantas/metabolismo , Espectrometría de Masas en Tándem
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