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1.
RNA ; 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38688558

RESUMO

The recognition of 5' splice site (5' ss) is one of the earliest steps of pre-mRNA splicing. To better understand the mechanism and regulation of 5' ss recognition, we selectively humanized components of the yeast U1 snRNP to reveal the function of these components in 5' ss recognition and splicing. We targeted U1C and Luc7, two proteins that interact with and stabilize the yeast U1 (yU1) snRNA and the 5' ss RNA duplex. We replaced the Zinc-Finger (ZnF) domain of yU1C with its human counterpart, which resulted in a cold-sensitive growth phenotype and moderate splicing defects. We next added an auxin-inducible degron to yLuc7 protein (to mimic the lack of Luc7Ls in human U1 snRNP) and found that Luc7-depleted yU1 snRNP resulted in the concomitant loss of PRP40 and Snu71 (two other essential yeast U1 snRNP proteins), and further biochemical analyses suggest a model of how these three proteins interact with each other in the U1 snRNP. The loss of these proteins resulted in a significant growth retardation accompanied by a global suppression of pre-mRNA splicing. The splicing suppression led to mitochondrial dysfunction as revealed by a release of Fe2+ into the growth medium and an induction of mitochondrial reactive oxygen species. Together, these observations indicate that the human U1C ZnF can substitute that of yeast, Luc7 is essential for the incorporation of the Luc7-Prp40-Snu71 trimer into yeast U1 snRNP, and splicing plays a major role in the regulation of mitochondrial function in yeast.

2.
Nature ; 573(7774): 375-380, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31485080

RESUMO

The molecular mechanisms of exon definition and back-splicing are fundamental unanswered questions in pre-mRNA splicing. Here we report cryo-electron microscopy structures of the yeast spliceosomal E complex assembled on introns, providing a view of the earliest event in the splicing cycle that commits pre-mRNAs to splicing. The E complex architecture suggests that the same spliceosome can assemble across an exon, and that it either remodels to span an intron for canonical linear splicing (typically on short exons) or catalyses back-splicing to generate circular RNA (on long exons). The model is supported by our experiments, which show that an E complex assembled on the middle exon of yeast EFM5 or HMRA1 can be chased into circular RNA when the exon is sufficiently long. This simple model unifies intron definition, exon definition, and back-splicing through the same spliceosome in all eukaryotes and should inspire experiments in many other systems to understand the mechanism and regulation of these processes.


Assuntos
Éxons , Íntrons , Modelos Moleculares , Splicing de RNA , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Microscopia Crioeletrônica , Estrutura Quaternária de Proteína , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/ultraestrutura , Spliceossomos/metabolismo , Spliceossomos/ultraestrutura
3.
Funct Integr Genomics ; 23(3): 244, 2023 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-37454326

RESUMO

Transposable elements exert a significant effect on the size and structure of eukaryotic genomes. Tc1/mariner superfamily elements represent the widely distributed and highly variable group of DNA transposons. Tc1/mariner elements include TLE/DD34-38E, MLE/DD34D, maT/DD37D, Visitor/DD41D, Guest/DD39D, mosquito/DD37E, and L18/DD37E families, all of which are well or less scarcely studied. However, more detailed research into the patterns of prevalence and diversity of Tc1/mariner transposons enables one to better understand the coevolution of the TEs and the eukaryotic genomes. We performed a detailed analysis of the maT/DD37D family in Cnidaria. The study of 77 genomic assemblies demonstrated that maT transposons are found in a limited number of cnidarian species belonging to classes Cubozoa (1 species), Hydrozoa (3 species) и Scyphozoa (5 species) only. The identified TEs were classified into 5 clades, with the representatives from Pelagiidae (class Scyphozoa) forming a separate clade of maT transposons, which has never been described previously. The potentially functional copies of maT transposons were identified in the hydrae. The phylogenetic analysis and the studies of distribution among the taxons and the evolutionary dynamics of the elements suggest that maT transposons of the cnidarians are the descendants of several independent invasion events occurring at different periods of time. We also established that the TEs of mosquito/DD37E family are found in Hydridae (class Hydrozoa) only. A comparison of maT and mosquito prevalence in two genomic assemblies of Hydra viridissima revealed obvious differences, thus demonstrating that each individual organism might carry a unique mobilome pattern. The results of the presented research make us better understand the diversity and evolution of Tc1/mariner transposons and their effect on the eukaryotic genomes.


Assuntos
Cnidários , Culicidae , Humanos , Animais , Culicidae/genética , Cnidários/genética , Filogenia , Elementos de DNA Transponíveis , Evolução Molecular
4.
Mol Phylogenet Evol ; 188: 107906, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37586577

RESUMO

DNA transposons play a crucial role in determining the size and structure of eukaryotic genomes. In this study, a new family of IS630-Tc1-mariner (ITm) DNA transposons, named Hiker (HK), was identified. HK is characterized by a DD35E catalytic domain and is distinct from all previously known families of the ITm group. Phylogenetic analyses showed that DD35E/Hiker forms a monophyletic clade with DD34E/Gambol, indicating that they may represent a separate superfamily of ITm. A total of 178 Hiker species were identified, with 170 found mainly in Actinopterygii, one in Chondrichthyes, six in Anura and one in Mollusca. Gambol (GM), on the other hand, are found in invertebrates, with 18 in Arthropoda and one in Platyhelminthes. Hiker transposons have a total length ranging from 2.14 to 3.67 kb and contain a single open reading frame that encodes a protein of approximately 370 amino acids (range 311-413 aa). They are flanked by short terminal inverted repeats (TIRs) of 16-30 base pairs and two base pair (TA) target-site duplications. In contrast, most transposons of the Gambol family have a total length of 1.35-5.96 kb, encode a transposase protein of approximately 350 amino acids (range 306-374 aa), and are flanked by TIRs that range from 32 to 1097 bp in length. Both Hiker and Gambol transposases have several conserved motifs, including helix-turn-helix (HTH) motifs and a DDE domain. Our study observed multiple amplification waves and repeated horizontal transfer (HT) events of HK transposons in vertebrate genomes, indicating their role in diversifying and shaping the genomes of Actinopterygii, Chondrichthyes, and Anura. Conversely, GM transposons showed few Horizontal transfer events. According to cell-based transposition assays, most HK transposons are likely inactive due to the truncated DNA binding domains of their transposases. We present an updated classification of the ITm group based on these findings, which will enhance the understanding of both the evolution of ITm transposons and that of their hosts.


Assuntos
Elementos de DNA Transponíveis , Transposases , Animais , Elementos de DNA Transponíveis/genética , Filogenia , Transposases/genética , Células Eucarióticas/metabolismo , Moluscos/genética
5.
Curr Issues Mol Biol ; 44(6): 2614-2621, 2022 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-35735619

RESUMO

An enhancer trap (ET) mediated by a transposon is an effective method for functional gene research. Here, an ET system based on a PB transposon that carries a mini Krt4 promoter (the keratin4 minimal promoter from zebrafish) and the green fluorescent protein gene (GFP) has been used to produce zebrafish ET lines. One enhancer trap line with eye-specific expression GFP named EYE was used to identify the trapped enhancers and genes. Firstly, GFP showed a temporal and spatial expression pattern with whole-embryo expression at 6, 12, and 24 hpf stages and eye-specific expression from 2 to 7 dpf. Then, the genome insertion sites were detected by splinkerette PCR (spPCR). The Krt4-GFP was inserted into the fourth intron of the gene itgav (integrin, alpha V) in chromosome 9 of the zebrafish genome, with the GFP direction the same as that of the itgav gene. By the alignment of homologous gene sequences in different species, three predicted endogenous enhancers were obtained. The trapped endogenous gene itgav, whose overexpression is related to hepatocellular carcinoma, showed a similar expression pattern as GFP detected by in situ hybridization, which suggested that GFP and itgav were possibly regulated by the same enhancers. In short, the zebrafish enhancer trap lines generated by the PB transposon-mediated enhancer trap technology in this study were valuable resources as visual markers to study the regulators and genes. This work provides an efficient method to identify and isolate tissue-specific enhancer sequences.

6.
Mol Phylogenet Evol ; 173: 107506, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35595006

RESUMO

Transposable elements (TEs) are mobile genetic elements in the genome and broadly distributed across both prokaryotes and eukaryotes, and play an important role in shaping the genome evolution of their hosts. hAT elements are thought to be the most widespread cut-and-paste DNA transposon found throughout the tree of life. Buster is a recently recognized family of hAT. However, the evolutionary profile of the Buster family, such as its taxonomic distribution, evolutionary pattern, and activities, remains largely unknown. We conducted a systematic analysis of the evolutionary landscape of the Buster family and found that most Buster transposons are 1.72-4.66 kilobases (kb) in length, encode 500-736-amino acid (aa) transposases and are flanked by short (10-18 bp) terminal inverted repeats (TIRs) and 8 bp target site duplications (TSDs). Buster family is widely distributed in 609 species, involving eight classes of invertebrates and most lineage of vertebrates (including mammals). Horizontal transfer events were detected across multiple phyla and classes of animals, which may have contributed to their wide distribution, and both parasites and invasive species may facilitate HT events of Buster in vertebrates. Our data also suggest that Buster transposons are young, highly active, and appear as intact copies in multiple lineages of animals. High percentages of intact copies (>30%) were identified in some Arthropoda, Actinopterygii, Agnatha, and reptile species, and some of these may be active. These data will help increase understanding of the evolution of the hAT superfamily and its impact on eukaryotic genome evolution.


Assuntos
Elementos de DNA Transponíveis , Transposases , Animais , Sequência de Bases , Elementos de DNA Transponíveis/genética , Eucariotos/genética , Evolução Molecular , Mamíferos/genética , Filogenia , Transposases/genética
7.
Chemistry ; 28(24): e202200480, 2022 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-35179269

RESUMO

Defunctionalization of readily available feedstocks to provide alkenes for the synthesis of multifunctional molecules represents an extremely useful process in organic synthesis. Herein, we describe a transition metal-free, simple and efficient strategy to access alkyl 1,2-bis(boronate esters) via regio- and diastereoselective diboration of secondary and tertiary alkyl halides (Br, Cl, I), tosylates, and alcohols. Control experiments demonstrated that the key to this high reactivity and selectivity is the addition of a combination of potassium iodide and N,N-dimethylacetamide (DMA). The practicality and industrial potential of this transformation are demonstrated by its operational simplicity, wide functional group tolerance, and the late-stage modification of complex molecules. From a drug discovery perspective, this synthetic method offers control of the position of diversification and diastereoselectivity in complex ring scaffolds, which would be especially useful in a lead optimization program.


Assuntos
Compostos Inorgânicos , Elementos de Transição , Álcoois , Alcenos , Técnicas de Química Sintética , Ésteres
8.
Methods ; 196: 30-35, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-33577981

RESUMO

Circular RNAs (circRNAs) generated from back-splicing of exons have been found in a wide range of eukaryotic species and exert a variety of biological functions. Unlike canonical splicing, the mechanism of back-splicing has long remained elusive. We recently determined the cryo-EM structure of the yeast spliceosomal E complex assembled on introns, leading us to hypothesize that the same E complex can assemble across an exon forming the exon-definition complex. This complex, when assembled on long exons, goes through the splicing cycle and catalyzes back-splicing to generate circRNAs. Supporting this hypothesis, we purified the yeast post-catalytic spliceosomal P complex (the best complex in the splicing cycle to trap splicing products and intermediates) and detected canonical and back-splicing products as well as splicing intermediates. Here we describe in detail this procedure, which may be applied to other organisms to facilitate research on the biogenesis and regulation of circRNA.


Assuntos
RNA Circular , RNA , Íntrons/genética , RNA/genética , RNA/metabolismo , Splicing de RNA , Spliceossomos/genética , Spliceossomos/metabolismo
9.
J Am Soc Nephrol ; 32(3): 580-596, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33593823

RESUMO

BACKGROUND: Galloway-Mowat syndrome (GAMOS) is characterized by neurodevelopmental defects and a progressive nephropathy, which typically manifests as steroid-resistant nephrotic syndrome. The prognosis of GAMOS is poor, and the majority of children progress to renal failure. The discovery of monogenic causes of GAMOS has uncovered molecular pathways involved in the pathogenesis of disease. METHODS: Homozygosity mapping, whole-exome sequencing, and linkage analysis were used to identify mutations in four families with a GAMOS-like phenotype, and high-throughput PCR technology was applied to 91 individuals with GAMOS and 816 individuals with isolated nephrotic syndrome. In vitro and in vivo studies determined the functional significance of the mutations identified. RESULTS: Three biallelic variants of the transcriptional regulator PRDM15 were detected in six families with proteinuric kidney disease. Four families with a variant in the protein's zinc-finger (ZNF) domain have additional GAMOS-like features, including brain anomalies, cardiac defects, and skeletal defects. All variants destabilize the PRDM15 protein, and the ZNF variant additionally interferes with transcriptional activation. Morpholino oligonucleotide-mediated knockdown of Prdm15 in Xenopus embryos disrupted pronephric development. Human wild-type PRDM15 RNA rescued the disruption, but the three PRDM15 variants did not. Finally, CRISPR-mediated knockout of PRDM15 in human podocytes led to dysregulation of several renal developmental genes. CONCLUSIONS: Variants in PRDM15 can cause either isolated nephrotic syndrome or a GAMOS-type syndrome on an allelic basis. PRDM15 regulates multiple developmental kidney genes, and is likely to play an essential role in renal development in humans.


Assuntos
Proteínas de Ligação a DNA/genética , Hérnia Hiatal/genética , Microcefalia/genética , Mutação de Sentido Incorreto , Nefrose/genética , Fatores de Transcrição/genética , Sequência de Aminoácidos , Substituição de Aminoácidos , Animais , Linhagem Celular , Pré-Escolar , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/deficiência , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Técnicas de Silenciamento de Genes , Técnicas de Inativação de Genes , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Lactente , Recém-Nascido , Masculino , Modelos Moleculares , Síndrome Nefrótica/genética , Podócitos/metabolismo , Polimorfismo de Nucleotídeo Único , Pronefro/embriologia , Pronefro/metabolismo , Estabilidade Proteica , Fatores de Transcrição/química , Fatores de Transcrição/deficiência , Xenopus laevis/embriologia , Xenopus laevis/genética , Dedos de Zinco/genética
10.
Molecules ; 27(17)2022 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-36080479

RESUMO

In this work, we performed a systematic comparison of different duration of solvent vapor annealing (SVA) treatment upon state-of-the-art PM6:SY1 blend film, which is to say for the first time, the insufficient, appropriate, and over-treatment's effect on the active layer is investigated. The power conversion efficiency (PCE) of corresponding organic solar cell (OSC) devices is up to 17.57% for the optimized system, surpassing the two counterparts. The properly tuned phase separation and formed interpenetrating network plays an important role in achieving high efficiency, which is also well-discussed by the morphological characterizations and understanding of device physics. Specifically, these improvements result in enhanced charge generation, transport, and collection. This work is of importance due to correlating post-treatment delicacy, thin-film morphology, and device performance in a decent way.

11.
Molecules ; 27(18)2022 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-36144539

RESUMO

Multicomponent organic solar cells (OSCs), such as the ternary and quaternary OSCs, not only inherit the simplicity of binary OSCs but further promote light harvesting and power conversion efficiency (PCE). Here, we propose a new type of multicomponent solar cells with non-fullerene acceptor isomers. Specifically, we fabricate OSCs with the polymer donor J71 and a mixture of isomers, ITCF, as the acceptors. In comparison, the ternary OSC devices with J71 and two structurally similar (not isomeric) NFAs (IT-DM and IT-4F) are made as control. The morphology experiments reveal that the isomers-containing blend film demonstrates increased crystallinity, more ideal domain size, and a more favorable packing orientation compared with the IT-DM/IT-4F ternary blend. The favorable orientation is correlated with the balanced charge transport, increased exciton dissociation and decreased bimolecular recombination in the ITCF-isomer-based blend film, which contributes to the high fill factor (FF), and thus the high PCE. Additionally, to evaluate the generality of this method, we examine other acceptor isomers including IT-M, IXIC-2Cl and SY1, which show same trend as the ITCF isomers. These results demonstrate that using isomeric blends as the acceptor can be a promising approach to promote the performance of multicomponent non-fullerene OSCs.

12.
PLoS Pathog ; 15(6): e1007819, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31194843

RESUMO

Recently identified broadly neutralizing antibodies (bnAbs) show great potential for clinical interventions against HIV-1 infection. However, resistant strains may impose substantial challenges. Here, we report on the identification and characterization of a panel of HIV-1 strains with broad and potent resistance against a large number of bnAbs, particularly those targeting the CD4-binding site (CD4bs). Site-directed mutagenesis revealed that several key epitope mutations facilitate resistance and are located in the inner domain, loop D, and ß23/loop V5/ß24 of HIV-1 gp120. The resistance is largely correlated with binding affinity of antibodies to the envelope trimers expressed on the cell surface. Our results therefore demonstrate the existence of broadly resistant HIV-1 strains against CD4bs neutralizing antibodies. Treatment strategies based on the CD4bs bnAbs must overcome such resistance to achieve optimal clinical outcomes.


Assuntos
Anticorpos Neutralizantes/imunologia , Antígenos CD4/imunologia , Epitopos/imunologia , Anticorpos Anti-HIV/imunologia , Proteína gp120 do Envelope de HIV/imunologia , HIV-1/imunologia , Anticorpos Neutralizantes/genética , Antígenos CD4/genética , Linhagem Celular , Epitopos/genética , Anticorpos Anti-HIV/genética , Proteína gp120 do Envelope de HIV/genética , HIV-1/genética , Humanos
13.
Mol Cell Biochem ; 475(1-2): 249-260, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32840737

RESUMO

Farrerol, a dihydroflavone isolated from Rhododendron dauricum L., can inhibit vascular smooth muscle cell (VSMC) proliferation and exert a protective effect on H2O2-induced vascular endothelial cells injury. In this study, we investigated the effects of farrerol on VSMC phenotypic modulation and balloon injury-induced vascular neointimal formation and explored the underlying mechanisms. Serum-starved rat thoracic aorta SMCs (RASMCs) were first pretreated with farrerol (3, 10, and 30 µM, respectively), U0126 (a MEK kinase inhibitor), and SB203580 (a p38 kinase inhibitor), and followed by treatment with serum (10% FBS). The expression of several VSMC-specific markers, including α-SMA, SM22α, and OPN, were analyzed by western blot. Phosphorylation of extracellular signal-regulated protein kinase 1/2 (ERK 1/2) and p38 mitogen-activated protein kinase (MAPK) was also investigated. Farrerol inhibited the serum-induced transition of RASMCs from the contractile to the synthetic phenotype, and this was associated with a decrease in α-SMA and SM22α expression, and an increase in OPN expression. Farrerol also inhibited serum-induced phosphorylation of ERK1/2 and p38MAPK in RASMCs. Moreover, U0126 and SB203580 both inhibited the serum-induced phenotypic transition of RASMCs. These findings indicate that farrerol can maintain the contractile phenotype of VSMCs partly via inactivating the ERK1/2 and p38 MAPK signaling pathways. Using a rat model of carotid artery balloon injury, inhibition of VSMC phenotypic transition and suppression of neointimal formation were confirmed in vivo following the perivascular application of farrerol. Our results suggested that farrerol could be a promising lead compound for the treatment of vascular proliferative diseases.


Assuntos
Cromonas/farmacologia , Proteína Quinase 1 Ativada por Mitógeno/antagonistas & inibidores , Proteína Quinase 3 Ativada por Mitógeno/antagonistas & inibidores , Músculo Liso Vascular/efeitos dos fármacos , Lesões do Sistema Vascular/tratamento farmacológico , Proteínas Quinases p38 Ativadas por Mitógeno/antagonistas & inibidores , Animais , Aorta/efeitos dos fármacos , Aorta/metabolismo , Células Cultivadas , Modelos Animais de Doenças , Masculino , Contração Muscular/efeitos dos fármacos , Músculo Liso Vascular/metabolismo , Neointima/metabolismo , Fosforilação , Compostos Fitoquímicos/farmacologia , Ratos , Ratos Sprague-Dawley , Transdução de Sinais , Lesões do Sistema Vascular/metabolismo , Lesões do Sistema Vascular/patologia
14.
Environ Sci Technol ; 52(15): 8627-8637, 2018 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-29952547

RESUMO

Nanoscale zerovalent iron (nZVI) likely finds its application in source zone remediation. Two approaches to modify nZVI have been reported: bimetal (Fe-Me) and sulfidated nZVI (S-nZVI). However, previous research has primarily focused on enhancing particle reactivity with these two modifications under more plume-like conditions. In this study, we systematically compared the trichloroethene (TCE) dechlorination pathway, rate, and electron selectivity of Fe-Me (Me: Pd, Ni, Cu, and Ag), S-nZVI, and nZVI with excess TCE simulating source zone conditions. TCE dechlorination on Fe-Me was primarily via hydrogenolysis while that on S-nZVI and nZVI was mainly via ß-elimination. The surface-area normalized TCE reduction rate ( k'SA) of Fe-Pd, S-nZVI, Fe-Ni, Fe-Cu, and Fe-Ag were ∼6800-, 190-, 130-, 20-, and 8-fold greater than nZVI. All bimetallic modification enhanced the competing hydrogen evolution reaction (HER) while sulfidation inhibited HER. Fe-Cu and Fe-Ag negligibly enhanced electron utilization efficiency (εe) while Fe-Pd, Fe-Ni, and S-nZVI dramatically increased εe from 2% to ∼100%, 69%, and 72%, respectively. Adsorbed atomic hydrogen was identified to be responsible for the TCE dechlorination on Fe-Me but not on S-nZVI. The enhanced dechlorination rate along with the reduced HER of S-nZVI can be explained by that FeS conducting major electrons mediated TCE dechlorination while Fe oxides conducting minor electrons mediated HER.


Assuntos
Tricloroetileno , Halogenação , Hidrogênio , Concentração de Íons de Hidrogênio , Ferro
15.
J Biol Chem ; 291(27): 14363-14372, 2016 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-27143356

RESUMO

The adenovirus early region 1A (E1A) oncoprotein hijacks host cells via direct interactions with many key cellular proteins, such as KAT2B, also known as PCAF (p300/CBP associated factor). E1A binds the histone acetyltransferase (HAT) domain of KAT2B to repress its transcriptional activation. However, the molecular mechanism by which E1A inhibits the HAT activity is not known. Here we demonstrate that a short and relatively conserved N-terminal motif (cNM) in the intrinsically disordered E1A protein is crucial for KAT2B interaction, and inhibits its HAT activity through a direct competition with acetyl-CoA, but not its substrate histone H3. Molecular modeling together with a series of mutagenesis experiments suggests that the major helix of E1A cNM binds to a surface of the acetyl-CoA pocket of the KAT2B HAT domain. Moreover, transient expression of the cNM peptide is sufficient to inhibit KAT2B-specific H3 acetylation H3K14ac in vivo Together, our data define an essential motif cNM in N-terminal E1A as an acetyl-CoA entry blocker that directly associates with the entrance of acetyl-CoA binding pocket to block the HAT domain access to its cofactor.


Assuntos
Proteínas E1A de Adenovirus/fisiologia , Lisina Acetiltransferases/antagonistas & inibidores , Acetilação , Proteínas E1A de Adenovirus/química , Motivos de Aminoácidos , Sequência de Aminoácidos , Humanos , Interações Hidrofóbicas e Hidrofílicas , Cinética , Modelos Moleculares , Homologia de Sequência de Aminoácidos
16.
BMC Struct Biol ; 14: 2, 2014 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-24423233

RESUMO

BACKGROUND: p300/CBP associating factor (PCAF, also known as KAT2B for lysine acetyltransferase 2B) is a catalytic subunit of megadalton metazoan complex ATAC (Ada-Two-A containing complex) for acetylation of histones. However, relatively little is known about the regulation of the enzymatic activity of PCAF. RESULTS: Here we present two dimeric structures of the PCAF acetyltransferase (HAT) domain. These dimerizations are mediated by either four-helical hydrophobic interactions or a ß-sheet extension. Our chemical cross-linking experiments in combined with site-directed mutagenesis demonstrated that the PCAF HAT domain mainly forms a dimer in solution through one of the observed interfaces. The results of maltose binding protein (MBP)-pulldown, co-immunoprecipitation and multiangle static light scattering experiments further indicated that PCAF dimeric state is detectable and may possibly exist in vivo. CONCLUSIONS: Taken together, our structural and biochemical studies indicate that PCAF appears to be a dimer in its functional ATAC complex.


Assuntos
Fatores de Transcrição de p300-CBP/química , Fatores de Transcrição de p300-CBP/metabolismo , Domínio Catalítico , Humanos , Modelos Moleculares , Mutagênese Sítio-Dirigida , Conformação Proteica , Multimerização Proteica , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Fatores de Transcrição de p300-CBP/genética
17.
Front Pharmacol ; 15: 1393597, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38933673

RESUMO

Background: Chemotherapy-induced nausea and vomiting (CINV) is one of the most frequent and critical side effects due to chemotherapeutics. In China, Xiao-Ban-Xia-Tang (XBXT) has already been applied extensively to prevent and treat CINV. However, there is limited testimony on the effectiveness and safety of this purpose, and there was no correlative systematic review. The aim of this review was to systematically evaluate the effectiveness and safety of XBXT in preventing and treating CINV. Methods: The systematic search was conducted in eight databases to acquire randomized controlled trials (RCTs) that appraised the effect of XBXT in treating CINV. The vomiting and nausea relief efficiency, eating efficiency, quality of life, and adverse reactions were explored for efficacy assessment. Bias risk was rated by manipulating the Cochrane risk of bias tool 2.0 (RoB 2). The retrieved investigations were analyzed by utilizing ReviewManager 5.4 and Stata 17.0. The quality of evidence was evaluated adopting the GRADE tool. Results: A total of 16 clinical RCTs of XBXT in the treatment of CINV were incorporated into the investigation, with a total of 1246 participants. The meta-analysis showed that compared with conventional antiemetic drugs, XBXT and antiemetics improved the vomiting relief efficiency (RR 1.35, 95% confidence interval: 1.25-1.46, p < 0.00001), nausea relief efficiency (N = 367, RR 1.23, 95% CI: 1.09-1.38, p < 0.00001), and quality of life (RR = 1.37, 95% CI: 1.14-1.65, p = 0.0009) and reduced the adverse events (N = 370, RR 0.53, 95% CI: 0.29-0.96, p = 0.04). XBXT and DARAs raised eating efficiency compared with DARAs (N = 208, RR 1.30, 95% CI: 1.07-1.57, p = 0.007). The data existed as statistically significant, and the publication bias was identified as relatively low from the funnel plot and trim and fill analysis. In addition, sensitivity analysis demonstrated robust outcomes. The quality of evidence for each outcome ranged from moderate to high. Conclusion: There is some encouraging evidence that XBXT and antiemetics had better therapeutic effects and safety in treating CINV than antiemetic drugs alone. The quality assessment and low publication bias indicated that the overall criterion was scientific. Better research is required to verify the evidence designed with large-scale RCTs and rigorous methods.Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=281046.

18.
J Ethnopharmacol ; 325: 117856, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38316220

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Hua Zhuo Ning Fu Decoction (HZD) is an empirical prescription from traditional Chinese medicine that shows excellent clinical results for psoriasis patients. Uncertainty lingered over HZD's potential anti-psoriasis mechanisms. AIM OF THE STUDY: The study's objective is to investigate the pharmacological processes and therapeutic effects of HZD on psoriasis. MATERIALS AND METHODS: In the initial phase of the study, an investigation was conducted to assess the effects of HZD on psoriasis-afflicted mice using an imiquimod (IMQ)-induced murine model. The experimental mice were randomly allocated to different groups, including the IMQ-induced model group, the control group, the HZD therapy groups with varying dosage levels (low, medium, and high), and Dexamethasone (DEX, the positive control medicine) group. Bioinformatics analysis and molecular docking were subsequently employed to identify the primary components and molecular targets associated with the therapeutic action of HZD in the context of psoriasis. Additionally, to find the impacts on metabolite regulation, plasma metabolomics based on ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-QTOF/MS) was used. It's interesting to note that the combined mechanisms from metabolomics were examined in tandem with the targets. In vivo tests were the last step in validating the potential mechanism. Throughout the trial, the following data were recorded: body weight, psoriasis area and severity index (PASI). The molecular targets connected to HZD's anti-psoriasis activities were revealed using histological examination, western blot (WB), and ELISA investigation. RESULTS: In mice induced with IMQ, HZD shown good anti-psoriasis effects in terms of PASI score and epidermal acanthosis. 95 HZD targets and 77 bioactive chemicals connected to psoriasis were found by bioinformatics research; of these, 7 key targets (EPHX2, PLA2G2A, TBXAS1, MAOA, ALDH1A3, ADH1A, and ADH1B) were linked to the mechanisms of HZD, the combination degree of which was finally expressed by the score of docking. In addition, HZD regulated nine metabolites. In line with this, HZD modified three metabolic pathways. Additionally, a combined examination of 7 key targets and 9 metabolites suggested that the metabolism of arachidonic acid might be the key metabolic route, which was identified by ELISA analysis. The in vivo investigation shown that HZD could control cytokines associated to inflammation (IL-10, TGF-ß, IL-17A, and IL-23), as well as important antioxidant system markers (ROS, GSH, and MDA). Moreover, HZD controlled iron levels and the expression of ferroptosis-related proteins (ACSL4 and GPX4), suggesting that ferroptosis played a crucial role in this process. CONCLUSIONS: Our findings demonstrated the whole mechanism and anti-psoriasis effectiveness of HZD, which will promote its clinical application and aid in the investigation of new bioactive components of HZD against psoriasis.


Assuntos
Medicamentos de Ervas Chinesas , Psoríase , Humanos , Camundongos , Animais , Simulação de Acoplamento Molecular , Psoríase/induzido quimicamente , Psoríase/tratamento farmacológico , Psoríase/patologia , Medicina Tradicional Chinesa , Medicamentos de Ervas Chinesas/farmacologia , Medicamentos de Ervas Chinesas/uso terapêutico , Metabolômica , Imiquimode , Biologia Computacional
19.
Adv Sci (Weinh) ; : e2400969, 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38774947

RESUMO

Novel active DNA transposons, such as Spy transposons from the PHIS superfamily, are identified through bioinformatics in this study. The native transposases cgSpy and cvSpy displayed transposition activities of approximately 85% and 35% compared to the hyperactive piggyBac transposase (hyPB). The cgSpy transposon showed unique characteristics, including a lack of overproduction inhibition and reduced efficiency for insertion sizes between 3.1 to 8.5 kb. Integration preferences of cgSpy are found in genes and regulatory regions, making it suitable for genetic manipulation. Evaluation in T-cell engineering demonstrated that cgSpy-mediated chimeric antigen receptor (CAR) modification is comparable to the PB system, indicating its potential utility in cell therapy. This study unveils the promising application of the active native transposase, Spy, from Colletes gigas, as a valuable tool for genetic engineering, particularly in T-cell manipulation.

20.
PLoS One ; 18(2): e0282429, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36854014

RESUMO

Infrared spectroscopy can quickly and non-destructively extract analytical information from samples. It can be applied to the authenticity identification of various Chinese herbal medicines, the prediction of the mixing amount of defective products, and the analysis of the origin. In this paper, the spectral information of Cornus officinalis from 11 origins was used as the research object, and the origin identification model of Cornus officinalis based on mid-infrared spectroscopy was established. First, principal component analysis was used to extract the absorbance data of Cornus officinalis in the wavenumber range of 551~3998 cm-1. The extracted principal components contain more than 99.8% of the information of the original data. Second, the extracted principal component information was used as input, and the origin category was used as output, and the origin identification model was trained with the help of support vector machine. In this paper, this combined model is called PCA-SVM combined model. Finally, the generalization ability of the PCA-SVM model is evaluated through an external test set. The three indicators of Accuracy, F1-Score, and Kappa coefficient are used to compare this model with other commonly used classification models such as naive Bayes model, decision trees, linear discriminant analysis, radial basis function neural network and partial least square discriminant analysis. The results show that PCA-SVM model is superior to other commonly used models in accuracy, F1 score and Kappa coefficient. In addition, compared with the SVM model with full spectrum data, the PCA-SVM model not only reduces the redundant variables in the model, but also has higher accuracy. Using this model to identify the origin of Cornus officinalis, the accuracy rate is 84.8%.


Assuntos
Cornus , Teorema de Bayes , Máquina de Vetores de Suporte , Análise Discriminante , Generalização Psicológica
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