Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 543
Filter
Add more filters

Country/Region as subject
Publication year range
1.
Circ Res ; 134(2): 165-185, 2024 01 19.
Article in English | MEDLINE | ID: mdl-38166463

ABSTRACT

BACKGROUND: Atherosclerosis is a globally prevalent chronic inflammatory disease with high morbidity and mortality. The development of atherosclerotic lesions is determined by macrophages. This study aimed to investigate the specific role of myeloid-derived CD147 (cluster of differentiation 147) in atherosclerosis and its translational significance. METHODS AND RESULTS: We generated mice with a myeloid-specific knockout of CD147 and mice with restricted CD147 overexpression, both in an apoE-deficient (ApoE-/-) background. Here, the myeloid-specific deletion of CD147 ameliorated atherosclerosis and inflammation. Consistent with our in vivo data, macrophages isolated from myeloid-specific CD147 knockout mice exhibited a phenotype shift from proinflammatory to anti-inflammatory macrophage polarization in response to lipopolysaccharide/IFN (interferon)-γ. These macrophages demonstrated a weakened proinflammatory macrophage phenotype, characterized by reduced production of NO and reactive nitrogen species derived from iNOS (inducible NO synthase). Mechanistically, the TRAF6 (tumor necrosis factor receptor-associated factor 6)-IKK (inhibitor of κB kinase)-IRF5 (IFN regulatory factor 5) signaling pathway was essential for the effect of CD147 on proinflammatory responses. Consistent with the reduced size of the necrotic core, myeloid-specific CD147 deficiency diminished the susceptibility of iNOS-mediated late apoptosis, accompanied by enhanced efferocytotic capacity mediated by increased secretion of GAS6 (growth arrest-specific 6) in proinflammatory macrophages. These findings were consistent in a mouse model with myeloid-restricted overexpression of CD147. Furthermore, we developed a new atherosclerosis model in ApoE-/- mice with humanized CD147 transgenic expression and demonstrated that the administration of an anti-human CD147 antibody effectively suppressed atherosclerosis by targeting inflammation and efferocytosis. CONCLUSIONS: Myeloid CD147 plays a crucial role in the growth of plaques by promoting inflammation in a TRAF6-IKK-IRF5-dependent manner and inhibiting efferocytosis by suppressing GAS6 during proinflammatory conditions. Consequently, the use of anti-human CD147 antibodies presents a complementary therapeutic approach to the existing lipid-lowering strategies for treating atherosclerotic diseases.


Subject(s)
Atherosclerosis , Plaque, Atherosclerotic , Mice , Animals , Efferocytosis , TNF Receptor-Associated Factor 6/metabolism , Atherosclerosis/metabolism , Inflammation/genetics , Mice, Knockout , Phenotype , Apolipoproteins E , Interferon Regulatory Factors/genetics , Mice, Inbred C57BL
2.
J Immunol ; 210(6): 699-707, 2023 03 15.
Article in English | MEDLINE | ID: mdl-36881905

ABSTRACT

C-reactive protein (CRP) is a highly conserved pentraxin with pattern recognition receptor-like activities. However, despite being used widely as a clinical marker of inflammation, the in vivo functions of CRP and its roles in health and disease remain largely unestablished. This is, to certain extent, due to the drastically different expression patterns of CRP in mice and rats, raising concerns about whether the functions of CRP are essential and conserved across species and how these model animals should be manipulated to examine the in vivo actions of human CRP. In this review, we discuss recent advances highlighting the essential and conserved functions of CRP across species, and propose that appropriately designed animal models can be used to understand the origin-, conformation-, and localization-dependent actions of human CRP in vivo. The improved model design will contribute to establishing the pathophysiological roles of CRP and facilitate the development of novel CRP-targeting strategies.


Subject(s)
C-Reactive Protein , Inflammation , Humans , Animals , Mice , Rats , Models, Animal
3.
BMC Genomics ; 25(1): 460, 2024 May 11.
Article in English | MEDLINE | ID: mdl-38730330

ABSTRACT

BACKGROUND: Zingiber officinale Roscoe, colloquially known as ginger, is a crop of significant medicinal and culinary value that frequently encounters adversity stemming from inhospitable environmental conditions. The MYB transcription factors have garnered recognition for their pivotal role in orchestrating a multitude of plant biological pathways. Nevertheless, the enumeration and characterization of the MYBs within Z. officinale Roscoe remains unknown. This study embarks on a genome-wide scrutiny of the MYB gene lineage in ginger, with the aim of cataloging all ZoMYB genes implicated in the biosynthesis of gingerols and curcuminoids, and elucidating their potential regulatory mechanisms in counteracting abiotic stress, thereby influencing ginger growth and development. RESULTS: In this study, we identified an MYB gene family comprising 231 members in ginger genome. This ensemble comprises 74 singular-repeat MYBs (1R-MYB), 156 double-repeat MYBs (R2R3-MYB), and a solitary triple-repeat MYB (R1R2R3-MYB). Moreover, a comprehensive analysis encompassing the sequence features, conserved protein motifs, phylogenetic relationships, chromosome location, and gene duplication events of the ZoMYBs was conducted. We classified ZoMYBs into 37 groups, congruent with the number of conserved domains and gene structure analysis. Additionally, the expression profiles of ZoMYBs during development and under various stresses, including ABA, cold, drought, heat, and salt, were investigated in ginger utilizing both RNA-seq data and qRT-PCR analysis. CONCLUSION: This work provides a comprehensive understanding of the MYB family in ginger and lays the foundation for the future investigation of the potential functions of ZoMYB genes in ginger growth, development and abiotic stress tolerance of ginger.


Subject(s)
Multigene Family , Phylogeny , Plant Proteins , Stress, Physiological , Transcription Factors , Zingiber officinale , Zingiber officinale/genetics , Stress, Physiological/genetics , Transcription Factors/genetics , Transcription Factors/metabolism , Plant Proteins/genetics , Plant Proteins/metabolism , Gene Expression Regulation, Plant
4.
J Am Chem Soc ; 146(18): 12723-12733, 2024 May 08.
Article in English | MEDLINE | ID: mdl-38654452

ABSTRACT

Enfumafungin-type antibiotics, represented by enfumafungin and fuscoatroside, belong to a distinct group of triterpenoids derived from fungi. These compounds exhibit significant antifungal properties with ibrexafungerp, a semisynthetic derivative of enfumafungin, recently gaining FDA's approval as the first oral antifungal drug for treating invasive vulvar candidiasis. Enfumafungin-type antibiotics possess a cleaved E-ring with an oxidized carboxyl group and a reduced methyl group at the break site, suggesting unprecedented C-C bond cleavage chemistry involved in their biosynthesis. Here, we show that a 4-gene (fsoA, fsoD, fsoE, fsoF) biosynthetic gene cluster is sufficient to yield fuscoatroside by heterologous expression in Aspergillus oryzae. Notably, FsoA is an unheard-of terpene cyclase-glycosyltransferase fusion enzyme, affording a triterpene glycoside product that relies on enzymatic fusion. FsoE is a P450 enzyme that catalyzes successive oxidation reactions at C19 to facilitate a C-C bond cleavage, producing an oxidized carboxyl group and a reduced methyl group that have never been observed in known P450 enzymes. Our study thus sets the important foundation for the manufacture of enfumafungin-type antibiotics using biosynthetic approaches.


Subject(s)
Antifungal Agents , Antifungal Agents/chemistry , Antifungal Agents/pharmacology , Antifungal Agents/metabolism , Aspergillus oryzae/enzymology , Aspergillus oryzae/metabolism , Multigene Family , Triterpenes/chemistry , Triterpenes/metabolism , Cytochrome P-450 Enzyme System/metabolism
5.
Rep Prog Phys ; 87(7)2024 Jul 03.
Article in English | MEDLINE | ID: mdl-38957891

ABSTRACT

Electron-phonon (e-p) coupling plays a crucial role in various physical phenomena, and regulation of e-p coupling is vital for the exploration and design of high-performance materials. However, the current research on this topic lacks accurate quantification, hindering further understanding of the underlying physical processes and its applications. In this work, we demonstrate quantitative regulation of e-p coupling, by pressure engineering andin-situspectroscopy. We successfully observe both a distinct vibrational mode and a strong Stokes shift in layered CrBr3, which are clear signatures of e-p coupling. This allows us to achieve precise quantification of the Huang-Rhys factorSat the actual sample temperature, thus accurately determining the e-p coupling strength. We further reveal that pressure efficiently regulates the e-p coupling in CrBr3, evidenced by a remarkable 40% increase inSvalue. Our results offer an approach for quantifying and modulating e-p coupling, which can be leveraged for exploring and designing functional materials with targeted e-p coupling strengths.

6.
Nat Prod Rep ; 41(5): 748-783, 2024 May 22.
Article in English | MEDLINE | ID: mdl-38265076

ABSTRACT

Covering: up to August 2023Terpenoids, which are widely distributed in animals, plants, and microorganisms, are a large group of natural products with diverse structures and various biological activities. They have made great contributions to human health as therapeutic agents, such as the anti-cancer drug paclitaxel and anti-malarial agent artemisinin. Accordingly, the biosynthesis of this important class of natural products has been extensively studied, which generally involves two major steps: hydrocarbon skeleton construction by terpenoid cyclases and skeleton modification by tailoring enzymes. Additionally, fungi (Ascomycota and Basidiomycota) serve as an important source for the discovery of terpenoids. With the rapid development of sequencing technology and bioinformatics approaches, genome mining has emerged as one of the most effective strategies to discover novel terpenoids from fungi. To date, numerous terpenoid cyclases, including typical class I and class II terpenoid cyclases as well as emerging UbiA-type terpenoid cyclases, have been identified, together with a variety of tailoring enzymes, including cytochrome P450 enzymes, flavin-dependent monooxygenases, and acyltransferases. In this review, our aim is to comprehensively present all fungal terpenoid cyclases identified up to August 2023, with a focus on newly discovered terpenoid cyclases, especially the emerging UbiA-type terpenoid cyclases, and their related tailoring enzymes from 2015 to August 2023.


Subject(s)
Fungi , Terpenes , Terpenes/metabolism , Terpenes/chemistry , Fungi/metabolism , Fungi/chemistry , Molecular Structure , Biological Products/metabolism , Biological Products/chemistry , Cytochrome P-450 Enzyme System/metabolism
7.
Anal Chem ; 96(14): 5702-5710, 2024 04 09.
Article in English | MEDLINE | ID: mdl-38538555

ABSTRACT

Glass nanopipets have been demonstrated to be a powerful tool for the sensing and discrimination of biomolecules, such as DNA strands with different lengths or configurations. Despite progress made in nanopipet-based sensors, it remains challenging to develop effective strategies that separate and sense in one operation. In this study, we demonstrate an agarose gel-filled nanopipet that enables hyphenated length-dependent separation and electrochemical sensing of short DNA fragments based on the electrokinetic flow of DNA molecules in the nanoconfined channel at the tip of the nanopipet. This nanoconfined electrokinetic chromatography (NEC) method is used to distinguish the mixture of DNA strands without labels, and the ionic current signals measured in real time show that the mixed DNA strands pass through the tip hole in order according to the molecular weight. With NEC, gradient separation and electrochemical measurement of biomolecules can be achieved simultaneously at the single-molecule level, which is further applied for programmable gene delivery into single living cells. Overall, NEC provides a multipurpose platform integrating separation, sensing, single-cell delivery, and manipulation, which may bring new insights into advanced bioapplication.


Subject(s)
DNA , Nanotechnology , DNA/chemistry , Nanotechnology/methods , Chromatography
8.
Plant Biotechnol J ; 22(3): 759-773, 2024 Mar.
Article in English | MEDLINE | ID: mdl-37937736

ABSTRACT

Soybean is one of the most economically important crops worldwide and an important source of unsaturated fatty acids and protein for the human diet. Consumer demand for healthy fats and oils is increasing, and the global demand for vegetable oil is expected to double by 2050. Identification of key genes that regulate seed fatty acid content can facilitate molecular breeding of high-quality soybean varieties with enhanced fatty acid profiles. Here, we analysed the genetic architecture underlying variations in soybean seed fatty acid content using 547 accessions, including mainly landraces and cultivars from northeastern China. Through fatty acid profiling, genome re-sequencing, population genomics analyses, and GWAS, we identified a SEIPIN homologue at the FA9 locus as an important contributor to seed fatty acid content. Transgenic and multiomics analyses confirmed that FA9 was a key regulator of seed fatty acid content with pleiotropic effects on seed protein and seed size. We identified two major FA9 haplotypes in 1295 resequenced soybean accessions and assessed their phenotypic effects in a field planting of 424 accessions. Soybean accessions carrying FA9H2 had significantly higher total fatty acid contents and lower protein contents than those carrying FA9H1 . FA9H2 was absent in wild soybeans but present in 13% of landraces and 26% of cultivars, suggesting that it may have been selected during soybean post-domestication improvement. FA9 therefore represents a useful genetic resource for molecular breeding of high-quality soybean varieties with specific seed storage profiles.


Subject(s)
Fatty Acids , Glycine max , Humans , Fatty Acids/metabolism , Glycine max/genetics , Fatty Acids, Unsaturated/metabolism , Plant Proteins/genetics , Plant Proteins/metabolism , Plant Oils/metabolism , Seeds/genetics , Seeds/metabolism
9.
J Org Chem ; 89(11): 7859-7864, 2024 Jun 07.
Article in English | MEDLINE | ID: mdl-38773955

ABSTRACT

Regioselective methods to access alkylated tetrazoles still remain a challenging goal. Herein, we describe a novel regioselective protocol for N2-arylation of tetrazoles with diazo compounds using inexpensive Al(OTf)3. This reaction could be conducted under mild conditions to access a diverse array of alkylated tetrazoles with 2-substituted tetrazoles as the major products, demonstrating a comprehensive range of substrate compatibility and excellent functional group compatibility. Mechanistic studies revealed a carbene-free process in this reaction procedure. Furthermore, the scale-up reaction and transformations of the N2-arylation of tetrazole products demonstrated the potential of this strategy.

10.
J Org Chem ; 89(7): 5038-5048, 2024 Apr 05.
Article in English | MEDLINE | ID: mdl-38517950

ABSTRACT

A novel method is described for the synthesis of 2,4-disubstituted oxazole and thiazole derivates via the coupling of α-diazoketones with (thio)amides or thioureas using trifluoromethanesulfonic acid (TfOH) as a catalyst. This protocol is characterized by mild reaction conditions, metal-free, and simplicity and also features good functional group tolerance, good to excellent yields, and a broad substrate scope with more than 40 examples. Experimental studies suggest a mechanism involving 2-oxo-2-phenylethyl trifluoromethanesulfonate as the key intermediate.

11.
Org Biomol Chem ; 22(39): 7971-7975, 2024 10 09.
Article in English | MEDLINE | ID: mdl-39269007

ABSTRACT

The cyclisation mechanism of the fungal fusicoccane (FC)-type diterpene synthase (DTS) TadA was investigated by extensive isotopic labelling experiments, and the pH-dependency of the product selectivity of this enzyme was explored. These studies provide new insights into the cyclisation mechanisms of FC-type DTSs.


Subject(s)
Alkyl and Aryl Transferases , Diterpenes , Diterpenes/chemistry , Diterpenes/metabolism , Alkyl and Aryl Transferases/metabolism , Cyclization , Hydrogen-Ion Concentration , Molecular Structure
12.
J Nat Prod ; 87(5): 1338-1346, 2024 May 24.
Article in English | MEDLINE | ID: mdl-38447084

ABSTRACT

Oxabornyl polyenes represent a unique group of polyketides characterized by a central polyene core flanked by a conserved oxabornyl moiety and a structurally diverse oxygen heterocyclic ring. They are widely distributed in fungi and possess a variety of biological activities. Due to the significant spatial separation between the two stereogenic ring systems, it is difficult to establish their overall relative configurations. Here, we isolated three oxabornyl polyenes, prugosenes A1-A3 (1-3), from Talaromyces sp. JNU18266-01. Although these compounds were first reported from Penicillium rugulosum, their overall relative and absolute configurations remained unassigned. By employing ozonolysis in combination with ECD calculations, we were able to establish their absolute configurations, and additionally obtained seven new chemical derivatives (4-10). Notably, through NMR data analysis and quantum chemical calculations, we achieved the structural revision of prugosene A2. Furthermore, prugosenes A1-A3 exhibited potent antiviral activity against the respiratory syncytial virus, with compound 1 displaying an IC50 value of 6.3 µM. Our study thus provides a valuable reference for absolute configuration assignment of oxabornyl polyene compounds.


Subject(s)
Polyenes , Polyenes/chemistry , Polyenes/pharmacology , Molecular Structure , Talaromyces/chemistry , Antiviral Agents/pharmacology , Antiviral Agents/chemistry , Respiratory Syncytial Viruses/drug effects , Humans
13.
J Nat Prod ; 87(9): 2139-2147, 2024 Sep 27.
Article in English | MEDLINE | ID: mdl-39194958

ABSTRACT

ortho-Quinone methides (o-QMs) are a class of highly reactive intermediates that serve as important nonisolable building blocks (NBBs) in organic synthesis and small-molecule library construction. Because of their instability and nonisolability, most reported o-QMs are generated through in situ chemical synthesis, and only a few natural o-QMs have been reported due to the lack of directed discovery strategies. Herein, a new natural o-QM precursor (trichophenol A, 2) was identified from the fungal strain of Trichoderma sp. AT0167 through genome mining, which was generated by trilA (nonreducing polyketide synthase) and trilB (2-oxoglutarate dependent dioxygenase). Combinatorial biosynthesis via two other known NRPKS genes with trilA and trilB was performed, leading to the generation of five new trichophenol o-QM oligomers (trichophenols D-H, 5-9). The strategy combining genome mining with combinatorial biosynthesis not only targetedly uncovered a new natural o-QM precursor but also produced various new molecules through oligomerization of the new o-QM and its designated o-QM acceptors without chemical synthesis and isolation of intermediates, which was named NBB genome mining-combinatorial biosynthesis strategy for o-QM molecule library construction. This study provides a new strategy for the targeted discovery of natural o-QMs and small-molecule library construction with natural o-QMs.


Subject(s)
Indolequinones , Indolequinones/chemistry , Molecular Structure , Polyketide Synthases/metabolism
14.
Bioorg Chem ; 152: 107726, 2024 Nov.
Article in English | MEDLINE | ID: mdl-39182256

ABSTRACT

Fusicoccane (FC)-type diterpenoids are a class of diterpenoids characterized by a unique 5-8-5 ring system and exhibit diverse biological activities. Recently, we identified a novel FC-type diterpene synthase MgMS, which produces a myrothec-15(17)-en-7-ol (1) hydrocarbon skeleton, however, its tailoring congeners have not been elucidated. Here, we discovered two additional gene clusters Bn and Np, each encoding a highly homologous terpene synthase to MgMS but distinct tailoring enzymes. Heterologous expression of the terpene synthases BnMS and NpMS yielded the same product as MgMS. Subsequent introduction of three P450 enzymes MgP450, BnP450 and NpP450 from individual gene clusters resulted in four new FC-type diterpenoids 2-5. Notably, MgP450 serves as the first enzyme responsible for hydroxylation of the C19 methyl group, whereas NpP450 functions as a multifunctional P450 enzyme involved in the oxidations at C5, C6, and C19 positions of the 5-8-5 tricyclic skeleton. C5 oxidation of the hydrocarbon skeleton 1 led to broadening of the NMR signals and incomplete spectra, which was resolved by high-temperature NMR spectral analysis.


Subject(s)
Cytochrome P-450 Enzyme System , Diterpenes , Oxidation-Reduction , Diterpenes/chemistry , Diterpenes/metabolism , Cytochrome P-450 Enzyme System/metabolism , Cytochrome P-450 Enzyme System/genetics , Molecular Structure
15.
Environ Toxicol ; 39(2): 479-486, 2024 Feb.
Article in English | MEDLINE | ID: mdl-37209271

ABSTRACT

The previous research has focused on the suppressive effects of Erianin on tumor progression, but its impact on cancer stemness has not been reported. This study aimed to investigate the effects of Erianin on lung cancer stemness. First, we screened various concentrations Erianin to ensure that it did not affect lung cancer cell viability. Subsequently, we found that Erianin significantly attenuated lung cancer stemness through various analyses, including qRT-PCR, western blot, sphere-formation, and ALDH activity detection. Furthermore, Erianin was shown to enhance chemosensitivity of lung cancer cells. Mechanistically, three inhibitors (cell apoptosis inhibitor, necrosis inhibitor, and ferroptosis inhibitor) were added into lung cancer cells with Erianin treatment, respectively, and we found that Erianin mainly suppressed lung cancer stemness through ferroptosis. Taken together, this study reveals that Erianin has the potential to suppress lung cancer stemness and could be a valuable chemotherapeutic enhancer for lung cancer.


Subject(s)
Bibenzyls , Ferroptosis , Lung Neoplasms , Humans , Lung Neoplasms/drug therapy , Cell Line, Tumor , Bibenzyls/pharmacology , Cell Proliferation
16.
Int Wound J ; 21(1): e14543, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38272821

ABSTRACT

After several institutions recommended salpingectomy as opposed to tubal ligation, we attempted to perform meta-analysis to compare operative properties and rates of postoperative wound infections. There are no temporal or linguistic limitations to our search in PubMed, Cochrane Library and Embase. The search was carried out in September 2023. The database search identified 401 potential studies and five studies were included in the meta-analysis. Our study involved a comparison of salpingectomy with tube ligating in female patients who wanted to be sterilized. Our trial included at least one result of the wound and haemorrhage. The articles that did not qualify for inclusion or did not submit data, and those who did not answer questions were excluded. Abstracts and full-text articles were assessed independently by two authors using blinding. Conflicting decisions were settled by consensus. The Cochrane-recommended ROBINS-I instrument has been applied to evaluate the risk of bias in clinical trials and to establish the quality of inclusion. Two authors separately evaluated the risk of bias for each trial; differences were settled by consensus. There were no statistically significant differences in the rate of postoperative wound infections among those who had received salpingectomy or tubal ligation (OR, 0.46; 95% CI, 0.18-1.20 p = 0.11). In the three trials, the risk of bleeding following the ligation of the fallopian tubes was lower than that of the salpingectomy group (OR, 1.25; 95% CI, 1.21-1.30 p < 0.0001). From this information we have come to the conclusion that it is possible to give preference to tubal ligation for reduction of bleeding in suitable circumstances, and that the findings currently do not provide sufficient evidence for a reduction in the risk of postoperative wound infection.


Subject(s)
Sterilization, Tubal , Humans , Female , Surgical Wound Infection/prevention & control , Salpingectomy , Fallopian Tubes/surgery
17.
Angew Chem Int Ed Engl ; 63(38): e202407895, 2024 Sep 16.
Article in English | MEDLINE | ID: mdl-38949843

ABSTRACT

The diterpene synthase AfAS was identified from Aspergillus fumigatiaffinis. Its amino acid sequence and-according to a structural model-active site architecture are highly similar to those of the fusicocca-2,10(14)-diene synthase PaFS, but AfAS produces a structurally much more complex diterpene with a novel 6-5-5-5 tetracyclic skeleton called asperfumene. The cyclisation mechanism of AfAS was elucidated through isotopic labelling experiments and DFT calculations. The reaction cascade proceeds in its initial steps through similar intermediates as for the PaFS cascade, but then diverges through an unusual vicinal deprotonation-reprotonation process that triggers a skeletal rearrangement at the entrance to the steps leading to the unique asperfumene skeleton. The structural model revealed only one major difference between the active sites: The PaFS residue F65 is substituted by I65 in AfAS. Intriguingly, site-directed mutagenesis experiments with both diterpene synthases revealed that position 65 serves as a bidirectional functional switch for the biosynthesis of tetracyclic asperfumene versus structurally less complex diterpenes.


Subject(s)
Diterpenes , Protons , Diterpenes/metabolism , Diterpenes/chemistry , Alkyl and Aryl Transferases/metabolism , Alkyl and Aryl Transferases/chemistry , Density Functional Theory , Catalytic Domain
18.
EMBO J ; 38(1)2019 01 03.
Article in English | MEDLINE | ID: mdl-30429206

ABSTRACT

OST1 (open stomata 1) protein kinase plays a central role in regulating freezing tolerance in Arabidopsis; however, the mechanism underlying cold activation of OST1 remains unknown. Here, we report that a plasma membrane-localized clade-E growth-regulating 2 (EGR2) phosphatase interacts with OST1 and inhibits OST1 activity under normal conditions. EGR2 is N-myristoylated by N-myristoyltransferase NMT1 at 22°C, which is important for its interaction with OST1. Moreover, myristoylation of EGR2 is required for its function in plant freezing tolerance. Under cold stress, the interaction of EGR2 and NMT1 is attenuated, leading to the suppression of EGR2 myristoylation in plants. Plant newly synthesized unmyristoylated EGR2 has decreased binding ability to OST1 and also interferes with the EGR2-OST1 interaction under cold stress. Consequently, the EGR2-mediated inhibition of OST1 activity is released. Consistently, mutations of EGRs cause plant tolerance to freezing, whereas overexpression of EGR2 exhibits decreased freezing tolerance. This study thus unravels a molecular mechanism underlying cold activation of OST1 by membrane-localized EGR2 and suggests that a myristoyl switch on EGR2 helps plants to adapt to cold stress.


Subject(s)
Acclimatization , Arabidopsis Proteins/metabolism , Arabidopsis Proteins/physiology , Arabidopsis , Cold Temperature/adverse effects , Protein Kinases/metabolism , Protein Phosphatase 2C/physiology , Acclimatization/genetics , Arabidopsis/enzymology , Arabidopsis/genetics , Arabidopsis/growth & development , Arabidopsis/metabolism , Cell Membrane/metabolism , Cold-Shock Response/genetics , Cold-Shock Response/physiology , Enzyme Activation/genetics , Fatty Acids, Monounsaturated/metabolism , Freezing , Gene Expression Regulation, Plant , Phosphorylation , Plants, Genetically Modified , Protein Processing, Post-Translational/genetics , Signal Transduction
19.
Anal Chem ; 95(30): 11273-11279, 2023 Aug 01.
Article in English | MEDLINE | ID: mdl-37478050

ABSTRACT

Dopamine (DA) is an important neurotransmitter, which not only participates in the regulation of neural processes but also plays critical roles in tumor progression and immunity. However, direct identification of DA-containing exosomes, as well as quantification of DA in single vesicles, is still challenging. Here, we report a nanopipette-assisted method to detect single exosomes and their dopamine contents via amperometric measurement. The resistive-pulse current measured can simultaneously provide accurate information of vesicle translocation and DA contents in single exosomes. Accordingly, DA-containing exosomes secreted from HeLa and PC12 cells under different treatment modes successfully detected the DA encapsulation efficiency and the amount of exosome secretion that distinguish between cell types. Furthermore, a custom machine learning model was constructed to classify the exosome signals from different sources, with an accuracy of more than 99%. Our strategy offers a useful tool for investigating single exosomes and their DA contents, which facilitates the analysis of DA-containing exosomes derived from other untreated or stimulated cells and may open up a new insight to the research of DA biology.

20.
BMC Plant Biol ; 23(1): 214, 2023 Apr 24.
Article in English | MEDLINE | ID: mdl-37095428

ABSTRACT

BACKGROUND: BRASSINAZOLE-RESISTANT (BZR) is a class of specific transcription factor (TFs) involved in brassinosteroid (BR) signal transduction. The regulatory mechanism of target genes mediated by BZR has become one of the key research areas in plant BR signaling networks. However, the functions of the BZR gene family in cucumber have not been well characterized. RESULTS: In this study, six CsBZR gene family members were identified by analyzing the conserved domain of BES1 N in the cucumber genome. The size of CsBZR proteins ranges from 311 to 698 amino acids and are mostly located in the nucleus. Phylogenetic analysis divided CsBZR genes into three subgroups. The gene structure and conserved domain showed that the BZR genes domain in the same group was conserved. Cis-acting element analysis showed that cucumber BZR genes were mainly involved in hormone response, stress response and growth regulation. The qRT-PCR results also confirmed CsBZR response to hormones and abiotic stress. CONCLUSION: Collectively, the CsBZR gene is involved in regulating cucumber growth and development, particularly in hormone response and response to abiotic stress. These findings provide valuable information for understanding the structure and expression patterns of BZR genes.


Subject(s)
Cucumis sativus , Cucumis sativus/genetics , Genome, Plant , Phylogeny , Brassinosteroids/metabolism , Multigene Family , Hormones/metabolism , Stress, Physiological/genetics , Gene Expression Regulation, Plant , Plant Proteins/genetics
SELECTION OF CITATIONS
SEARCH DETAIL