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1.
Cell ; 173(3): 677-692.e20, 2018 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-29677512

RESUMO

RNA-binding proteins (RBPs) with prion-like domains (PrLDs) phase transition to functional liquids, which can mature into aberrant hydrogels composed of pathological fibrils that underpin fatal neurodegenerative disorders. Several nuclear RBPs with PrLDs, including TDP-43, FUS, hnRNPA1, and hnRNPA2, mislocalize to cytoplasmic inclusions in neurodegenerative disorders, and mutations in their PrLDs can accelerate fibrillization and cause disease. Here, we establish that nuclear-import receptors (NIRs) specifically chaperone and potently disaggregate wild-type and disease-linked RBPs bearing a NLS. Karyopherin-ß2 (also called Transportin-1) engages PY-NLSs to inhibit and reverse FUS, TAF15, EWSR1, hnRNPA1, and hnRNPA2 fibrillization, whereas Importin-α plus Karyopherin-ß1 prevent and reverse TDP-43 fibrillization. Remarkably, Karyopherin-ß2 dissolves phase-separated liquids and aberrant fibrillar hydrogels formed by FUS and hnRNPA1. In vivo, Karyopherin-ß2 prevents RBPs with PY-NLSs accumulating in stress granules, restores nuclear RBP localization and function, and rescues degeneration caused by disease-linked FUS and hnRNPA2. Thus, NIRs therapeutically restore RBP homeostasis and mitigate neurodegeneration.


Assuntos
Transporte Ativo do Núcleo Celular , Príons/química , Proteínas de Ligação a RNA/química , Receptores Citoplasmáticos e Nucleares/química , Adulto , Idoso , Animais , Citoplasma/química , Proteínas de Ligação a DNA/química , Drosophila melanogaster , Feminino , Proteínas de Fluorescência Verde/química , Células HEK293 , Células HeLa , Homeostase , Humanos , Carioferinas/química , Masculino , Pessoa de Meia-Idade , Chaperonas Moleculares/química , Mutação , Doenças Neurodegenerativas/patologia , Domínios Proteicos , Proteína EWS de Ligação a RNA/química , Fatores Associados à Proteína de Ligação a TATA/química , beta Carioferinas/química
2.
Cell ; 158(3): 607-19, 2014 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-25083871

RESUMO

MicroRNAs are well known to mediate translational repression and mRNA degradation in the cytoplasm. Various microRNAs have also been detected in membrane-compartmentalized organelles, but the functional significance has remained elusive. Here, we report that miR-1, a microRNA specifically induced during myogenesis, efficiently enters the mitochondria where it unexpectedly stimulates, rather than represses, the translation of specific mitochondrial genome-encoded transcripts. We show that this positive effect requires specific miR:mRNA base-pairing and Ago2, but not its functional partner GW182, which is excluded from the mitochondria. We provide evidence for the direct action of Ago2 in mitochondrial translation by crosslinking immunoprecipitation coupled with deep sequencing (CLIP-seq), functional rescue with mitochondria-targeted Ago2, and selective inhibition of the microRNA machinery in the cytoplasm. These findings unveil a positive function of microRNA in mitochondrial translation and suggest a highly coordinated myogenic program via miR-1-mediated translational stimulation in the mitochondria and repression in the cytoplasm.


Assuntos
Diferenciação Celular , MicroRNAs/metabolismo , Mitocôndrias/metabolismo , Mioblastos/metabolismo , Miócitos Cardíacos/metabolismo , Biossíntese de Proteínas , Animais , Proteínas Argonautas/metabolismo , Linhagem Celular , Camundongos , Mioblastos/citologia , Miócitos Cardíacos/citologia
3.
Nat Immunol ; 17(3): 241-9, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26692175

RESUMO

The gene encoding PTEN is one of the most frequently mutated tumor suppressor-encoding genes in human cancer. While PTEN's function in tumor suppression is well established, its relationship to anti-microbial immunity remains unknown. Here we found a pivotal role for PTEN in the induction of type I interferon, the hallmark of antiviral innate immunity, that was independent of the pathway of the kinases PI(3)K and Akt. PTEN controlled the import of IRF3, a master transcription factor responsible for IFN-ß production, into the nucleus. We further identified a PTEN-controlled negative phosphorylation site at Ser97 of IRF3 and found that release from this negative regulation via the phosphatase activity of PTEN was essential for the activation of IRF3 and its import into the nucleus. Our study identifies crosstalk between PTEN and IRF3 in tumor suppression and innate immunity.


Assuntos
Imunidade Inata/imunologia , Fator Regulador 3 de Interferon/imunologia , Interferon Tipo I/imunologia , PTEN Fosfo-Hidrolase/imunologia , Infecções por Respirovirus/imunologia , Infecções por Rhabdoviridae/imunologia , Animais , Linhagem Celular , Linhagem Celular Tumoral , Núcleo Celular , Proliferação de Células , Citocinas/imunologia , Células Dendríticas/imunologia , Eletroforese em Gel de Poliacrilamida , Imunofluorescência , Técnicas de Transferência de Genes , Células HEK293 , Humanos , Immunoblotting , Imunoprecipitação , Fator Regulador 3 de Interferon/genética , Fator Regulador 7 de Interferon/genética , Células MCF-7 , Macrófagos/imunologia , Espectrometria de Massas , Camundongos , Microscopia Confocal , Mutagênese Sítio-Dirigida , PTEN Fosfo-Hidrolase/genética , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação , Proteínas Proto-Oncogênicas c-akt/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Vírus Sendai , Vesiculovirus
4.
Mol Cell ; 79(3): 443-458.e7, 2020 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-32649883

RESUMO

Despite the prominent role of TDP-43 in neurodegeneration, its physiological and pathological functions are not fully understood. Here, we report an unexpected role of TDP-43 in the formation of dynamic, reversible, liquid droplet-like nuclear bodies (NBs) in response to stress. Formation of NBs alleviates TDP-43-mediated cytotoxicity in mammalian cells and fly neurons. Super-resolution microscopy reveals distinct functions of the two RRMs in TDP-43 NB formation. TDP-43 NBs are partially colocalized with nuclear paraspeckles, whose scaffolding lncRNA NEAT1 is dramatically upregulated in stressed neurons. Moreover, increase of NEAT1 promotes TDP-43 liquid-liquid phase separation (LLPS) in vitro. Finally, we discover that the ALS-associated mutation D169G impairs the NEAT1-mediated TDP-43 LLPS and NB assembly, causing excessive cytoplasmic translocation of TDP-43 to form stress granules, which become phosphorylated TDP-43 cytoplasmic foci upon prolonged stress. Together, our findings suggest a stress-mitigating role and mechanism of TDP-43 NBs, whose dysfunction may be involved in ALS pathogenesis.


Assuntos
Esclerose Lateral Amiotrófica/genética , Proteínas de Ligação a DNA/genética , Corpos de Inclusão Intranuclear/metabolismo , Neurônios/metabolismo , RNA Longo não Codificante/genética , Esclerose Lateral Amiotrófica/metabolismo , Esclerose Lateral Amiotrófica/patologia , Animais , Animais Geneticamente Modificados , Arsenitos/farmacologia , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/metabolismo , Córtex Cerebral/ultraestrutura , Grânulos Citoplasmáticos/efeitos dos fármacos , Grânulos Citoplasmáticos/metabolismo , Grânulos Citoplasmáticos/ultraestrutura , Proteínas de Ligação a DNA/metabolismo , Modelos Animais de Doenças , Drosophila melanogaster , Regulação da Expressão Gênica , Células HEK293 , Células HeLa , Humanos , Corpos de Inclusão Intranuclear/efeitos dos fármacos , Corpos de Inclusão Intranuclear/ultraestrutura , Camundongos , Mutação , Neurônios/efeitos dos fármacos , Neurônios/ultraestrutura , Cultura Primária de Células , Transporte Proteico/efeitos dos fármacos , RNA Longo não Codificante/metabolismo , Transdução de Sinais , Estresse Fisiológico
5.
Mol Cell ; 77(1): 82-94.e4, 2020 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-31630970

RESUMO

FUS is a nuclear RNA-binding protein, and its cytoplasmic aggregation is a pathogenic signature of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). It remains unknown how the FUS-RNA interactions contribute to phase separation and whether its phase behavior is affected by ALS-linked mutations. Here we demonstrate that wild-type FUS binds single-stranded RNA stoichiometrically in a length-dependent manner and that multimers induce highly dynamic interactions with RNA, giving rise to small and fluid condensates. In contrast, mutations in arginine display a severely altered conformation, static binding to RNA, and formation of large condensates, signifying the role of arginine in driving proper RNA interaction. Glycine mutations undergo rapid loss of fluidity, emphasizing the role of glycine in promoting fluidity. Strikingly, the nuclear import receptor Karyopherin-ß2 reverses the mutant defects and recovers the wild-type FUS behavior. We reveal two distinct mechanisms underpinning potentially disparate pathogenic pathways of ALS-linked FUS mutants.


Assuntos
Esclerose Lateral Amiotrófica/genética , Demência Frontotemporal/genética , Mutação/genética , Proteína FUS de Ligação a RNA/genética , RNA/genética , Transporte Ativo do Núcleo Celular/genética , Glicina/genética , Humanos
6.
Mol Cell ; 73(4): 815-829.e7, 2019 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-30772174

RESUMO

Somatic cells can be reprogrammed into induced pluripotent stem cells (iPSCs), which is a highly heterogeneous process. Here we report the cell fate continuum during somatic cell reprogramming at single-cell resolution. We first develop SOT to analyze cell fate continuum from Oct4/Sox2/Klf4- or OSK-mediated reprogramming and show that cells bifurcate into two categories, reprogramming potential (RP) or non-reprogramming (NR). We further show that Klf4 contributes to Cd34+/Fxyd5+/Psca+ keratinocyte-like NR fate and that IFN-γ impedes the final transition to chimera-competent pluripotency along the RP cells. We analyze more than 150,000 single cells from both OSK and chemical reprograming and identify additional NR/RP bifurcation points. Our work reveals a generic bifurcation model for cell fate decisions during somatic cell reprogramming that may be applicable to other systems and inspire further improvements for reprogramming.


Assuntos
Diferenciação Celular/genética , Linhagem da Célula/genética , Técnicas de Reprogramação Celular , Reprogramação Celular/genética , Células-Tronco Pluripotentes Induzidas/fisiologia , Células-Tronco Embrionárias Murinas/fisiologia , Análise de Sequência de RNA , Análise de Célula Única , Animais , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Células-Tronco Pluripotentes Induzidas/metabolismo , Interferon gama/genética , Interferon gama/metabolismo , Fator 4 Semelhante a Kruppel , Masculino , Camundongos , Camundongos da Linhagem 129 , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos CBA , Camundongos Transgênicos , Células-Tronco Embrionárias Murinas/metabolismo , Fenótipo , Transdução de Sinais , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
7.
Nature ; 582(7812): 370-374, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32555490

RESUMO

The well known trade-off between hardness and toughness (resistance to fracture) makes simultaneous improvement of both properties challenging, especially in diamond. The hardness of diamond can be increased through nanostructuring strategies1,2, among which the formation of high-density nanoscale twins - crystalline regions related by symmetry - also toughens diamond2. In materials other than diamond, there are several other promising approaches to enhancing toughness in addition to nanotwinning3, such as bio-inspired laminated composite toughening4-7, transformation toughening8 and dual-phase toughening9, but there has been little research into such approaches in diamond. Here we report the structural characterization of a diamond composite hierarchically assembled with coherently interfaced diamond polytypes (different stacking sequences), interwoven nanotwins and interlocked nanograins. The architecture of the composite enhances toughness more than nanotwinning alone, without sacrificing hardness. Single-edge notched beam tests yield a toughness up to five times that of synthetic diamond10, even greater than that of magnesium alloys. When fracture occurs, a crack propagates through diamond nanotwins of the 3C (cubic) polytype along {111} planes, via a zigzag path. As the crack encounters regions of non-3C polytypes, its propagation is diffused into sinuous fractures, with local transformation into 3C diamond near the fracture surfaces. Both processes dissipate strain energy, thereby enhancing toughness. This work could prove useful in making superhard materials and engineering ceramics. By using structural architecture with synergetic effects of hardening and toughening, the trade-off between hardness and toughness may eventually be surmounted.

8.
Mol Cell ; 71(5): 703-717.e9, 2018 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-30100264

RESUMO

In amyotrophic lateral sclerosis (ALS) and frontotemporal degeneration (FTD), cytoplasmic aggregates of hyperphosphorylated TDP-43 accumulate and colocalize with some stress granule components, but how pathological TDP-43 aggregation is nucleated remains unknown. In Drosophila, we establish that downregulation of tankyrase, a poly(ADP-ribose) (PAR) polymerase, reduces TDP-43 accumulation in the cytoplasm and potently mitigates neurodegeneration. We establish that TDP-43 non-covalently binds to PAR via PAR-binding motifs embedded within its nuclear localization sequence. PAR binding promotes liquid-liquid phase separation of TDP-43 in vitro and is required for TDP-43 accumulation in stress granules in mammalian cells and neurons. Stress granule localization initially protects TDP-43 from disease-associated phosphorylation, but upon long-term stress, stress granules resolve, leaving behind aggregates of phosphorylated TDP-43. Finally, small-molecule inhibition of Tankyrase-1/2 in mammalian cells inhibits formation of cytoplasmic TDP-43 foci without affecting stress granule assembly. Thus, Tankyrase inhibition antagonizes TDP-43-associated pathology and neurodegeneration and could have therapeutic utility for ALS and FTD.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Poli Adenosina Difosfato Ribose/metabolismo , Esclerose Lateral Amiotrófica/metabolismo , Animais , Células COS , Linhagem Celular , Núcleo Celular/metabolismo , Chlorocebus aethiops , Citoplasma/metabolismo , Drosophila , Feminino , Degeneração Lobar Frontotemporal/metabolismo , Masculino , Mamíferos/metabolismo , Doenças Neurodegenerativas/metabolismo , Neurônios/metabolismo , Fosforilação/fisiologia , Ratos , Ratos Sprague-Dawley
9.
Mol Cell ; 69(5): 787-801.e8, 2018 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-29499134

RESUMO

MicroRNA-mediated gene silencing is a fundamental mechanism in the regulation of gene expression. It remains unclear how the efficiency of RNA silencing could be influenced by RNA-binding proteins associated with the microRNA-induced silencing complex (miRISC). Here we report that fused in sarcoma (FUS), an RNA-binding protein linked to neurodegenerative diseases including amyotrophic lateral sclerosis (ALS), interacts with the core miRISC component AGO2 and is required for optimal microRNA-mediated gene silencing. FUS promotes gene silencing by binding to microRNA and mRNA targets, as illustrated by its action on miR-200c and its target ZEB1. A truncated mutant form of FUS that leads its carriers to an aggressive form of ALS, R495X, impairs microRNA-mediated gene silencing. The C. elegans homolog fust-1 also shares a conserved role in regulating the microRNA pathway. Collectively, our results suggest a role for FUS in regulating the activity of microRNA-mediated silencing.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/metabolismo , Inativação Gênica , MicroRNAs/metabolismo , RNA de Helmintos/metabolismo , Proteína FUS de Ligação a RNA/metabolismo , Esclerose Lateral Amiotrófica/genética , Esclerose Lateral Amiotrófica/metabolismo , Esclerose Lateral Amiotrófica/patologia , Animais , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/genética , Células HEK293 , Humanos , Camundongos , MicroRNAs/genética , RNA de Helmintos/genética , Proteína FUS de Ligação a RNA/genética
10.
Mol Cell ; 72(1): 71-83.e7, 2018 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-30220561

RESUMO

Cancer cells entail metabolic adaptation and microenvironmental remodeling to survive and progress. Both calcium (Ca2+) flux and Ca2+-dependent signaling play a crucial role in this process, although the underlying mechanism has yet to be elucidated. Through RNA screening, we identified one long noncoding RNA (lncRNA) named CamK-A (lncRNA for calcium-dependent kinase activation) in tumorigenesis. CamK-A is highly expressed in multiple human cancers and involved in cancer microenvironment remodeling via activation of Ca2+-triggered signaling. Mechanistically, CamK-A activates Ca2+/calmodulin-dependent kinase PNCK, which in turn phosphorylates IκBα and triggers calcium-dependent nuclear factor κB (NF-κB) activation. This regulation results in the tumor microenvironment remodeling, including macrophage recruitment, angiogenesis, and tumor progression. Notably, our human-patient-derived xenograft (PDX) model studies demonstrate that targeting CamK-A robustly impaired cancer development. Clinically, CamK-A expression coordinates with the activation of CaMK-NF-κB axis, and its high expression indicates poor patient survival rate, suggesting its role as a potential biomarker and therapeutic target.


Assuntos
Carcinogênese/genética , Neoplasias/genética , RNA Longo não Codificante/genética , Microambiente Tumoral/genética , Sinalização do Cálcio/genética , Proteína Quinase Tipo 1 Dependente de Cálcio-Calmodulina/genética , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Humanos , Macrófagos/metabolismo , Macrófagos/patologia , NF-kappa B/genética , Neoplasias/patologia , Fosforilação , Transdução de Sinais/genética , Ensaios Antitumorais Modelo de Xenoenxerto
11.
Proc Natl Acad Sci U S A ; 120(39): e2306841120, 2023 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-37722061

RESUMO

Although direct generation of high-value complex molecules and feedstock by coupling of ubiquitous small molecules such as CO2 and N2 holds great appeal as a potential alternative to current fossil-fuel technologies, suitable scalable and efficient catalysts to this end are not currently available as yet to be designed and developed. To this end, here we prepare and characterize SbxBi1-xOy clusters for direct urea synthesis from CO2 and N2 via C-N coupling. The introduction of Sb in the amorphous BiOx clusters changes the adsorption geometry of CO2 on the catalyst from O-connected to C-connected, creating the possibility for the formation of complex products such as urea. The modulated Bi(II) sites can effectively inject electrons into N2, promoting C-N coupling by advantageous modification of the symmetry for the frontier orbitals of CO2 and N2 involved in the rate-determining catalytic step. Compared with BiOx, SbxBi1-xOy clusters result in a lower reaction potential of only -0.3 V vs. RHE, an increased production yield of 307.97 µg h-1 mg-1cat, and a higher Faraday efficiency (10.9%), pointing to the present system as one of the best catalysts for urea synthesis in aqueous systems among those reported so far. Beyond the urea synthesis, the present results introduce and demonstrate unique strategies to modulate the electronic states of main group p-metals toward their use as effective catalysts for multistep electroreduction reactions requiring C-N coupling.

12.
J Neurosci ; 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-39019614

RESUMO

The simple act of viewing and grasping an object involves complex sensorimotor control mechanisms that have been shown to vary as a function of multiple object and other task features such as object size, shape, weight, and wrist orientation. However, these features have been mostly studied in isolation. In contrast, given the nonlinearity of motor control its computations require multiple features to be incorporated concurrently. Therefore, the present study tested the hypothesis that grasp computations integrate multiple task features superadditively in particular when these features are relevant for the same action phase. We asked male and female human participants to reach-to-grasp objects of different shapes and sizes with different wrist orientations. Also, we delayed movement onset using auditory signals to specify which effector to use. Using electroencephalography (EEG) and representative dissimilarity analysis to map the time course of cortical activity we found that grasp computations formed superadditive integrated representations of grasp features during different planning phases of grasping. Shape-by-size representations and size-by-orientation representations occurred before and after effector specification, respectively, and could not be explained by single-feature models. These observations are consistent with the brain performing different preparatory, phase-specific computations; visual object analysis to identify grasp points at abstract visual levels and downstream sensorimotor preparatory computations for reach-to-grasp trajectories. Our results suggest the brain adheres to the needs of nonlinear motor control for integration. Furthermore, they show that examining the superadditive influence of integrated representations can serve as a novel lens to map the computations underlying sensorimotor control.Significance Statement The nonlinearity of the sensorimotor control of grasping should require computations to incorporate multiple task features such as object shape, size, and orientation concurrently. However, grasp research so far has primarily investigated the influences of task features in isolation. In contrast, integrated representations of task features have been studied in cognitive paradigms showing that multiple visual and action features are joined together in abstract representations based on working memory or priming effects called events files. Using multivariate analysis of EEG, here we observe a new form of integrated representations of task features for grasping that cannot be explained by single-feature models or event files. Our approach offers novel insights into the preparatory processes of sensorimotor grasp control.

13.
J Neurosci ; 44(29)2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-38789263

RESUMO

The intention to act influences the computations of various task-relevant features. However, little is known about the time course of these computations. Furthermore, it is commonly held that these computations are governed by conjunctive neural representations of the features. But, support for this view comes from paradigms arbitrarily combining task features and affordances, thus requiring representations in working memory. Therefore, the present study used electroencephalography and a well-rehearsed task with features that afford minimal working memory representations to investigate the temporal evolution of feature representations and their potential integration in the brain. Female and male human participants grasped objects or touched them with a knuckle. Objects had different shapes and were made of heavy or light materials with shape and weight being relevant for grasping, not for "knuckling." Using multivariate analysis showed that representations of object shape were similar for grasping and knuckling. However, only for grasping did early shape representations reactivate at later phases of grasp planning, suggesting that sensorimotor control signals feed back to the early visual cortex. Grasp-specific representations of material/weight only arose during grasp execution after object contact during the load phase. A trend for integrated representations of shape and material also became grasp-specific but only briefly during the movement onset. These results suggest that the brain generates action-specific representations of relevant features as required for the different subcomponents of its action computations. Our results argue against the view that goal-directed actions inevitably join all features of a task into a sustained and unified neural representation.


Assuntos
Eletroencefalografia , Força da Mão , Movimento , Desempenho Psicomotor , Humanos , Masculino , Feminino , Adulto , Desempenho Psicomotor/fisiologia , Força da Mão/fisiologia , Adulto Jovem , Movimento/fisiologia , Estimulação Luminosa/métodos , Percepção Visual/fisiologia , Memória de Curto Prazo/fisiologia
14.
Plant Cell ; 34(10): 3577-3610, 2022 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-35766883

RESUMO

Moso bamboo (Phyllostachys edulis) shows remarkably rapid growth (114.5 cm/day), but the underlying biological mechanisms remain unclear. After examining more than 12,750 internodes from more than 510 culms from 17 Moso populations, we identified internode 18 as a representative internode for rapid growth. This internode includes a 2-cm cell division zone (DZ), a cell elongation zone up to 12 cm, and a secondary cell wall (SCW) thickening zone. These zones elongated 11.8 cm, produced approximately 570,000,000 cells, and deposited ∼28 mg g-1 dry weight (DW) lignin and ∼44 mg g-1 DW cellulose daily, far exceeding vegetative growth observed in other plants. We used anatomical, mathematical, physiological, and genomic data to characterize development and transcriptional networks during rapid growth in internode 18. Our results suggest that (1) gibberellin may directly trigger the rapid growth of Moso shoots, (2) decreased cytokinin and increased auxin accumulation may trigger cell DZ elongation, and (3) abscisic acid and mechanical pressure may stimulate rapid SCW thickening via MYB83L. We conclude that internode length involves a possible tradeoff mediated by mechanical pressure caused by rapid growth, possibly influenced by environmental temperature and regulated by genes related to cell division and elongation. Our results provide insight into the rapid growth of Moso bamboo.


Assuntos
Giberelinas , Transcriptoma , Ácido Abscísico/farmacologia , Citocininas , Regulação da Expressão Gênica de Plantas , Ácidos Indolacéticos , Lignina , Poaceae/genética , Transcriptoma/genética
15.
Chem Rev ; 123(13): 8859-8941, 2023 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-37358266

RESUMO

Amorphous materials are metastable solids with only short-range order at the atomic scale, which results from local intermolecular chemical bonding. The lack of long-range order typical of crystals endows amorphous nanomaterials with unconventional and intriguing structural features, such as isotropic atomic environments, abundant surface dangling bonds, highly unsaturated coordination, etc. Because of these features and the ensuing modulation in electronic properties, amorphous nanomaterials display potential for practical applications in different areas. Motivated by these elements, here we provide an overview of the unique structural features, the general synthetic methods, and the potential for applications covered by contemporary research in amorphous nanomaterials. Furthermore, we discussed the possible theoretical mechanism for amorphous nanomaterials, examining how the unique structural properties and electronic configurations contribute to their exceptional performance. In particular, the structural benefits of amorphous nanomaterials as well as their enhanced electrocatalytic, optical, and mechanical properties, thereby clarifying the structure-function relationships, are highlighted. Finally, a perspective on the preparation and utilization of amorphous nanomaterials to establish mature systems with a superior hierarchy for various applications is introduced, and an outlook for future challenges and opportunities at the frontiers of this rapidly advancing field is proposed.

16.
Proc Natl Acad Sci U S A ; 119(45): e2206846119, 2022 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-36322735

RESUMO

Heat stress limits plant growth, development, and crop yield, but how plant cells precisely sense and transduce heat stress signals remains elusive. Here, we identified a conserved heat stress response mechanism to elucidate how heat stress signal is transmitted from the cytoplasm into the nucleus for epigenetic modifiers. We demonstrate that HISTONE DEACETYLASE 9 (HDA9) transduces heat signals from the cytoplasm to the nucleus to play a positive regulatory role in heat responses in Arabidopsis. Heat specifically induces HDA9 accumulation in the nucleus. Under heat stress, the phosphatase PP2AB'ß directly interacts with and dephosphorylates HDA9 to protect HDA9 from 26S proteasome-mediated degradation, leading to the translocation of nonphosphorylated HDA9 to the nucleus. This heat-induced enrichment of HDA9 in the nucleus depends on the nucleoporin HOS1. In the nucleus, HDA9 binds and deacetylates the target genes related to signaling transduction and plant development to repress gene expression in a transcription factor YIN YANG 1-dependent and -independent manner, resulting in rebalance of plant development and heat response. Therefore, we uncover an HDA9-mediated positive regulatory module in the heat shock signal transduction pathway. More important, this cytoplasm-to-nucleus translocation of HDA9 in response to heat stress is conserved in wheat and rice, which confers the mechanism significant implication potential for crop breeding to cope with global climate warming.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas , Células Vegetais/metabolismo , Melhoramento Vegetal , Arabidopsis/metabolismo , Histona Desacetilases/genética , Histona Desacetilases/metabolismo
17.
Chem Soc Rev ; 53(2): 684-713, 2024 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-38116613

RESUMO

Crystalline-amorphous hybrid materials (CA-HMs) possess the merits of both pure crystalline and amorphous phases. Abundant dangling bonds, unsaturated coordination atoms, and isotropic structural features in the amorphous phase, as well as relatively high electronic conductivity and thermodynamic structural stability of the crystalline phase simultaneously take effect in CA-HMs. Furthermore, the atomic and bandgap mismatch at the CA-HM interface can introduce more defects as extra active sites, reservoirs for promoted catalytic and electrochemical performance, and induce built-in electric field for facile charge carrier transport. Motivated by these intriguing features, herein, we provide a comprehensive overview of CA-HMs on various aspects-from synthetic methods to multiple applications. Typical characteristics of CA-HMs are discussed at the beginning, followed by representative synthetic strategies of CA-HMs, including hydrothermal/solvothermal methods, deposition techniques, thermal adjustment, and templating methods. Diverse applications of CA-HMs, such as electrocatalysis, batteries, supercapacitors, mechanics, optoelectronics, and thermoelectrics along with underlying structure-property mechanisms are carefully elucidated. Finally, challenges and perspectives of CA-HMs are proposed with an aim to provide insights into the future development of CA-HMs.

18.
J Am Chem Soc ; 146(19): 13527-13535, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38691638

RESUMO

Closing the carbon and nitrogen cycles by electrochemical methods using renewable energy to convert abundant or harmful feedstocks into high-value C- or N-containing chemicals has the potential to transform the global energy landscape. However, efficient conversion avenues have to date been mostly realized for the independent reduction of CO2 or NO3-. The synthesis of more complex C-N compounds still suffers from low conversion efficiency due to the inability to find effective catalysts. To this end, here we present amorphous bismuth-tin oxide nanosheets, which effectively reduce the energy barrier of the catalytic reaction, facilitating efficient and highly selective urea production. With enhanced CO2 adsorption and activation on the catalyst, a C-N coupling pathway based on *CO2 rather than traditional *CO is realized. The optimized orbital symmetry of the C- (*CO2) and N-containing (*NO2) intermediates promotes a significant increase in the Faraday efficiency of urea production to an outstanding value of 78.36% at -0.4 V vs RHE. In parallel, the nitrogen and carbon selectivity for urea formation is also enhanced to 90.41% and 95.39%, respectively. The present results and insights provide a valuable reference for the further development of new catalysts for efficient synthesis of high-value C-N compounds from CO2.

19.
J Am Chem Soc ; 146(28): 19295-19302, 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-38943666

RESUMO

Oxygen vacancies are generally considered to play a crucial role in the oxygen evolution reaction (OER). However, the generation of active sites created by oxygen vacancies is inevitably restricted by their condensation and elimination reactions. To overcome this limitation, here, we demonstrate a novel photoelectric reconstruction strategy to incorporate atomically dispersed Cu into ultrathin (about 2-3 molecular) amorphous oxyhydroxide (a-CuM, M = Co, Ni, Fe, or Zn), facilitating deprotonation of the reconstructed oxyhydroxide to generate high-valence Cu. The in situ XAFS results and first-principles calculations reveal that Cu atoms are stabilized at high valence during the OER process due to Jahn-Teller distortion, resulting in para-type double oxygen vacancies as dynamically stable catalytic sites. The optimal a-CuCo catalyst exhibits a record-high mass activity of 3404.7 A g-1 at an overpotential of 300 mV, superior to the benchmarking hydroxide and oxide catalysts. The developed photoelectric reconstruction strategy opens up a new pathway to construct in situ stable oxygen vacancies by high-valence Cu single sites, which extends the design rules for creating dynamically stable active sites.

20.
Br J Cancer ; 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38918556

RESUMO

BACKGROUND: This study aims to develop a stacking model for accurately predicting axillary lymph node (ALN) response to neoadjuvant chemotherapy (NAC) using longitudinal MRI in breast cancer. METHODS: We included patients with node-positive breast cancer who received NAC following surgery from January 2012 to June 2022. We collected MRIs before and after NAC, and extracted radiomics features from the tumour, peritumour, and ALN regions. The Mann-Whitney U test, least absolute shrinkage and selection operator, and Boruta algorithm were used to select features. We utilised machine learning techniques to develop three single-modality models and a stacking model for predicting ALN response to NAC. RESULTS: This study consisted of a training cohort (n = 277), three external validation cohorts (n = 313, 164, and 318), and a prospective cohort (n = 81). Among the 1153 patients, 60.62% achieved ypN0. The stacking model achieved excellent AUCs of 0.926, 0.874, and 0.862 in the training, external validation, and prospective cohort, respectively. It also showed lower false-negative rates (FNRs) compared to radiologists, with rates of 14.40%, 20.85%, and 18.18% (radiologists: 40.80%, 50.49%, and 63.64%) in three cohorts. Additionally, there was a significant difference in disease-free survival between high-risk and low-risk groups (p < 0.05). CONCLUSIONS: The stacking model can accurately predict ALN status after NAC in breast cancer, showing a lower false-negative rate than radiologists. TRIAL REGISTRATION NUMBER: The clinical trial numbers were NCT03154749 and NCT04858529.

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