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1.
Mol Cell ; 81(14): 2960-2974.e7, 2021 07 15.
Artículo en Inglés | MEDLINE | ID: mdl-34111398

RESUMEN

The transition of oxidized 5-methylcytosine (5mC) intermediates into the base excision repair (BER) pipeline to complete DNA demethylation remains enigmatic. We report here that UHRF2, the only paralog of UHRF1 in mammals that fails to rescue Uhrf1-/- phenotype, is physically and functionally associated with BER complex. We show that UHRF2 is allosterically activated by 5-hydroxymethylcytosine (5hmC) and acts as a ubiquitin E3 ligase to catalyze K33-linked polyubiquitination of XRCC1. This nonproteolytic action stimulates XRCC1's interaction with the ubiquitin binding domain-bearing RAD23B, leading to the incorporation of TDG into BER complex. Integrative epigenomic analysis in mouse embryonic stem cells reveals that Uhrf2-fostered TDG-RAD23B-BER complex is functionally linked to the completion of DNA demethylation at active promoters and that Uhrf2 ablation impedes DNA demethylation on latent enhancers that undergo poised-to-active transition during neuronal commitment. Together, these observations highlight an essentiality of 5hmC-switched UHRF2 E3 ligase activity in commissioning the accomplishment of active DNA demethylation.


Asunto(s)
5-Metilcitosina/análogos & derivados , Regulación Alostérica/genética , Ubiquitina-Proteína Ligasas/genética , Ubiquitinación/genética , Proteína 1 de Reparación por Escisión del Grupo de Complementación Cruzada de las Lesiones por Rayos X/genética , 5-Metilcitosina/metabolismo , Animales , Línea Celular , Línea Celular Tumoral , Desmetilación del ADN , Metilación de ADN/genética , Reparación del ADN/genética , Enzimas Reparadoras del ADN/genética , Proteínas de Unión al ADN/genética , Células HEK293 , Humanos , Células MCF-7 , Ratones , Ratones Noqueados , Regiones Promotoras Genéticas/genética , Unión Proteica/genética
2.
Plant Physiol ; 194(2): 1104-1119, 2024 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-37647540

RESUMEN

Cold affects the growth and development of plants. MYB transcription factors and histone H3K4me3 transferase ARABIDOPSIS TRITHORAXs (ATXs) play important regulatory functions in the process of plant resistance to low-temperature stress. In this study, DgMYB expression was responsive to low temperature, and overexpression of DgMYB led to increased tolerance, whereas the dgmyb mutant resulted in decreased tolerance of Chrysanthemum morifolium (Dendranthema grandiflorum var. Jinba) to cold stresses. Interestingly, we found that only peroxidase (POD) activity differed substantially between wild type (WT), overexpression lines, and the mutant line. A DgATX H3K4me3 methylase that interacts with DgMYB was isolated by further experiments. DgATX expression was also responsive to low temperature. Overexpression of DgATX led to increased tolerance, whereas the dgatx mutant resulted in decreased tolerance of chrysanthemum to cold stresses. Moreover, the dgmyb, dgatx, and dgmyb dgatx double mutants all led to reduced H3K4me3 levels at DgPOD, thus reducing DgPOD expression. Together, our results show that DgMYB interacts with DgATX, allowing DgATX to specifically target DgPOD, altering H3K4me3 levels, increasing DgPOD expression, and thereby reducing the accumulation of reactive oxygen species (ROS) in chrysanthemum.


Asunto(s)
Arabidopsis , Chrysanthemum , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Histonas/metabolismo , Chrysanthemum/genética , Chrysanthemum/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Modificadas Genéticamente/metabolismo , Regulación de la Expresión Génica de las Plantas , Frío , Arabidopsis/genética , Arabidopsis/metabolismo
3.
Small ; 20(27): e2309661, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38268235

RESUMEN

Soft robots based on flexible materials have attracted the attention due to high flexibility and great environmental adaptability. Among the common driving modes, electricity, light, and magnetism have the limitations of wiring, poor penetration capability, and sophisticated equipment, respectively. Here, an emerging wireless driving mode is proposed for the soft crawling robot based on wireless power transfer (WPT) technology. The receiving coil at the robot's tail, as an energy transfer station, receives energy from the transmitting coil and supplies the electrothermal responsiveness to drive the robot's crawling. By regulating the WPT's duration to control the friction between the robot and the ground, bidirectional crawling is realized. Furthermore, the receiving coil is also employed as a sensory organ to equip the robot with localization, ID recognition, and sensing capabilities based on electromagnetic coupling. This work provides an innovative and promising strategy for the design and integration of soft crawling robots, exhibiting great potential in the field of intelligent robots.

4.
Plant Physiol ; 194(1): 243-257, 2023 Dec 30.
Artículo en Inglés | MEDLINE | ID: mdl-37399189

RESUMEN

Plant lignocellulosic biomass, i.e. secondary cell walls of plants, is a vital alternative source for bioenergy. However, the acetylation of xylan in secondary cell walls impedes the conversion of biomass to biofuels. Previous studies have shown that REDUCED WALL ACETYLATION (RWA) proteins are directly involved in the acetylation of xylan but the regulatory mechanism of RWAs is not fully understood. In this study, we demonstrate that overexpression of a Populus trichocarpa PtRWA-C gene increases the level of xylan acetylation and increases the lignin content and S/G ratio, ultimately yielding poplar woody biomass with reduced saccharification efficiency. Furthermore, through gene coexpression network and expression quantitative trait loci (eQTL) analysis, we found that PtRWA-C was regulated not only by the secondary cell wall hierarchical regulatory network but also by an AP2 family transcription factor HARDY (HRD). Specifically, HRD activates PtRWA-C expression by directly binding to the PtRWA-C promoter, which is also the cis-eQTL for PtRWA-C. Taken together, our findings provide insights into the functional roles of PtRWA-C in xylan acetylation and consequently saccharification and shed light on synthetic biology approaches to manipulate this gene and alter cell wall properties. These findings have substantial implications for genetic engineering of woody species, which could be used as a sustainable source of biofuels, valuable biochemicals, and biomaterials.


Asunto(s)
Populus , Populus/genética , Populus/metabolismo , Xilanos/metabolismo , Acetilación , Biomasa , Biocombustibles/análisis , Plantas/metabolismo , Pared Celular/metabolismo , Lignina/metabolismo
5.
Plant Physiol ; 191(3): 1492-1504, 2023 03 17.
Artículo en Inglés | MEDLINE | ID: mdl-36546733

RESUMEN

Deciduous woody plants like poplar (Populus spp.) have seasonal bud dormancy. It has been challenging to simultaneously delay the onset of bud dormancy in the fall and advance bud break in the spring, as bud dormancy, and bud break were thought to be controlled by different genetic factors. Here, we demonstrate that heterologous expression of the REVEILLE1 gene (named AaRVE1) from Agave (Agave americana) not only delays the onset of bud dormancy but also accelerates bud break in poplar in field trials. AaRVE1 heterologous expression increases poplar biomass yield by 166% in the greenhouse. Furthermore, we reveal that heterologous expression of AaRVE1 increases cytokinin contents, represses multiple dormancy-related genes, and up-regulates bud break-related genes, and that AaRVE1 functions as a transcriptional repressor and regulates the activity of the DORMANCY-ASSOCIATED PROTEIN 1 (DRM1) promoter. Our findings demonstrate that AaRVE1 appears to function as a regulator of bud dormancy and bud break, which has important implications for extending the growing season of deciduous trees in frost-free temperate and subtropical regions to increase crop yield.


Asunto(s)
Agave , Populus , Proteínas de Plantas/metabolismo , Populus/metabolismo , Estaciones del Año , Factores de Transcripción/genética , Factores de Transcripción/metabolismo
6.
Brain Behav Immun ; 123: 123-142, 2024 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-39243987

RESUMEN

Multiple sclerosis (MS) is a chronic autoimmune disease of the central nervous system (CNS) mediated by CD4+ T helper (Th) cells, and characterized by immune cell infiltration, demyelination and neurodegeneration, with no definitive cure available. Thus, it is pivotal and imperative to acquire more profound comprehension of the underlying mechanisms implicated in MS. Dysregulated immune responses are widely believed to play a primary role in the pathogenesis of MS. Recently, a plethora of studies have demonstrated the involvement of T follicular helper (Tfh) cells and tertiary lymphoid-like structures (TLSs) in the pathogenesis and progression of MS. Cathepsin C (CatC) is a cysteine exopeptidase which is crucial for the activation of immune-cell-associated serine proteinases in many inflammatory diseases in peripheral system, such as rheumatoid arthritis and septicemia. We have previously demonstrated that CatC is involved in neuroinflammation and exacerbates demyelination in both cuprizone-induced and experimental autoimmune encephalomyelitis (EAE) mouse models. However, the underlying immunopathological mechanism remains elusive. In the present study, we established a recombinant myelin oligodendrocyte glycoprotein 35-55 peptide-induced EAE model using conditional CatC overexpression mice to investigate the effects of CatC on the alteration of CD4+ Th subsets, including Th1, Th2, Th17, Tfh and T regulatory cells. Our findings demonstrated that CatC particularly enhanced the population of Tfh cell in the brain, resulting in the earlier onset and more severe chronic syndrome of EAE. Furthermore, CatC promoted the formation of TLSs in the brain, leading to persistent neuroinflammation and exacerbating the severity of EAE in the chronic phase. Conversely, treatment with AZD7986, a specific inhibitor of CatC, effectively attenuated the syndrome of EAE and its effects caused by CatC both in vivo and in vitro. These findings provide a novel insight into the critical role of CatC in innate and adaptive immunity in EAE, and specific inhibitor of CatC, AZD7986, may contribute to potential therapeutic strategies for MS.

7.
Environ Sci Technol ; 2024 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-39031076

RESUMEN

Ice can serve as a significant temporary repository and conveyance mechanism for microplastics (MPs). MPs present in the water column can become entrapped within developing ice formations, subsequently being sequestered and transported by ice floes. With changing temperatures, MPs stored in ice can be released back into the environment, while freezing conditions can alter the properties of MPs, ultimately affecting the fate of MPs in the environment. Freezing of MPs in freshwater ice results in the aggregation of MP particles due to physical compression, leading to an increase in particle size once the MPs are released from the ice. The freezing-induced aggregation enhances buoyancy effects, accelerating the settling/rising velocity of MPs in water. Additionally, freezing can lead to enhanced surface wetting alterations, thus improving the dispersion of hydrophobic MPs. The presence of salt in the water can mitigate the effect of freezing on MPs due to the formation of a brine network within the ice structure, which reduces the pressure on MPs entrapped by ice. In cold regions, numerous MPs undergo freezing and thawing, re-entering the water column.

8.
Environ Sci Technol ; 58(6): 2944-2955, 2024 Feb 13.
Artículo en Inglés | MEDLINE | ID: mdl-38306690

RESUMEN

The estuary is an energetic area connecting the inland, river, and ocean. The migration of microplastics (MPs) in this highly complex area is tied to the entire ecosystem. In this study, the effects of cohesive SPM (clay) and noncohesive SPM (sand) on the vertical migration of positively buoyant MPs, polyethylene (PE), and negatively buoyant MPs, polytetrafluoroethylene (PTFE), in the estuarine environment under hydrodynamic disturbances were investigated. The settling of positively buoyant MPs was more reliant on the cohesive SPM compared to the settling of negatively buoyant MPs. Moreover, MPs interacting with the SPM mixture at a clay-to-sand ratio of 1:9 settled more efficiently than those interacting with clay alone. A significant positive correlation was observed between MP settling percentage and the salinity level. MP settling percentage was significantly negatively correlated with fluid shear stress for both types of MPs, meanwhile, negatively buoyant MPs were able to resist greater hydraulic disturbances. In the low-energy mixing state, for both types of MPs, the settling percentage reached about 50% in only 10 min. The resuspension process of MPs under hydrodynamic disturbances was also uncovered. Additionally, the migration and potential sites of MPs were described in the context of prevalent environmental phenomena in estuaries.


Asunto(s)
Material Particulado , Contaminantes Químicos del Agua , Material Particulado/análisis , Microplásticos , Plásticos , Salinidad , Arena , Hidrodinámica , Arcilla , Ecosistema , Contaminantes Químicos del Agua/análisis , Monitoreo del Ambiente , Estuarios
9.
Cell ; 138(4): 660-72, 2009 Aug 21.
Artículo en Inglés | MEDLINE | ID: mdl-19703393

RESUMEN

Lysine-specific demethylase 1 (LSD1) exerts pathway-specific activity in animal development and has been linked to several high-risk cancers. Here, we report that LSD1 is an integral component of the Mi-2/nucleosome remodeling and deacetylase (NuRD) complex. Transcriptional target analysis revealed that the LSD1/NuRD complexes regulate several cellular signaling pathways including TGFbeta1 signaling pathway that are critically involved in cell proliferation, survival, and epithelial-to-mesenchymal transition. We demonstrated that LSD1 inhibits the invasion of breast cancer cells in vitro and suppresses breast cancer metastatic potential in vivo. We found that LSD1 is downregulated in breast carcinomas and that its level of expression is negatively correlated with that of TGFbeta1. Our data provide a molecular basis for the interplay of histone demethylation and deacetylation in chromatin remodeling. By enlisting LSD1, the NuRD complex expands its chromatin remodeling capacity to include ATPase, histone deacetylase, and histone demethylase.


Asunto(s)
Neoplasias de la Mama/metabolismo , Histona Desacetilasas/metabolismo , Metástasis de la Neoplasia/genética , Oxidorreductasas N-Desmetilantes/metabolismo , Animales , Línea Celular Tumoral , Ensamble y Desensamble de Cromatina , Regulación hacia Abajo , Regulación Neoplásica de la Expresión Génica , Células HeLa , Histona Demetilasas , Humanos , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2 , Ratones , Ratones SCID , Trasplante de Neoplasias , Nucleosomas/metabolismo , Oxidorreductasas N-Desmetilantes/química , Fragmentos de Péptidos/metabolismo , Factor de Crecimiento Transformador beta1/metabolismo
10.
Macromol Rapid Commun ; 45(14): e2400105, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38623606

RESUMEN

Intelligent materials derived from green and renewable bio-based materials garner widespread attention recently. Herein, shape memory polyurethane composite (PUTA/Fe) with fast response to near-infrared (NIR) light is successfully prepared by introducing Fe3+ into the tannic acid-based polyurethane (PUTA) matrix through coordination between Fe3+ and tannic acid. The results show that the excellent NIR light response ability is due to the even distribution of Fe3+ filler with good photo-thermal conversion ability. With the increase of Fe3+ content, the NIR light response shape recovery rate of PUTA/Fe composite films is significantly improved, and the shape recovery time is reduced from over 60 s to 40 s. In addition, the mechanical properties of PUTA/Fe composite film are also improved. Importantly, owing to the dynamic phenol-carbamate network within the polymer matrix, the PUTA/Fe composite film can reshape its permanent shape through topological rearrangement and show its good NIR light response shape memory performance. Therefore, PUTA/Fe composites with high content of bio-based material (TA content of 15.1-19.4%) demonstrate the shape memory characteristics of fast response to NIR light; so, it will have great potential in the application of new intelligent materials including efficient and environmentally friendly smart photothermal responder.


Asunto(s)
Carbamatos , Rayos Infrarrojos , Hierro , Poliuretanos , Taninos , Taninos/química , Poliuretanos/química , Hierro/química , Carbamatos/química , Fenoles/química , Fenol/química , Materiales Inteligentes/química , Polifenoles
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