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1.
Int J Mol Sci ; 25(13)2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-39000240

RESUMO

GAI-RGA-and-SCR (GRAS) transcription factors can regulate many biological processes such as plant growth and development and stress defense, but there are few related studies in sugar beet. Salt stress can seriously affect the yield and quality of sugar beet (Beta vulgaris). Therefore, this study used bioinformatics methods to identify GRAS transcription factors in sugar beet and analyzed their structural characteristics, evolutionary relationships, regulatory networks and salt stress response patterns. A total of 28 BvGRAS genes were identified in the whole genome of sugar beet, and the sequence composition was relatively conservative. According to the topology of the phylogenetic tree, BvGRAS can be divided into nine subfamilies: LISCL, SHR, PAT1, SCR, SCL3, LAS, SCL4/7, HAM and DELLA. Synteny analysis showed that there were two pairs of fragment replication genes in the BvGRAS gene, indicating that gene replication was not the main source of BvGRAS family members. Regulatory network analysis showed that BvGRAS could participate in the regulation of protein interaction, material transport, redox balance, ion homeostasis, osmotic substance accumulation and plant morphological structure to affect the tolerance of sugar beet to salt stress. Under salt stress, BvGRAS and its target genes showed an up-regulated expression trend. Among them, BvGRAS-15, BvGRAS-19, BvGRAS-20, BvGRAS-21, LOC104892636 and LOC104893770 may be the key genes for sugar beet's salt stress response. In this study, the structural characteristics and biological functions of BvGRAS transcription factors were analyzed, which provided data for the further study of the molecular mechanisms of salt stress and molecular breeding of sugar beet.


Assuntos
Beta vulgaris , Regulação da Expressão Gênica de Plantas , Filogenia , Proteínas de Plantas , Estresse Salino , Fatores de Transcrição , Beta vulgaris/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Estresse Salino/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Genoma de Planta , Redes Reguladoras de Genes , Sintenia
2.
Methods Mol Biol ; 2832: 205-212, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38869797

RESUMO

One of the major plant stress level indicators is reactive oxygen species (ROS). They have been known to play a central role in regulating plant responses to various environmental stresses. This book chapter specifically covers abiotic stress induced by a drought hormone abscisic acid and biotic stress induced by Pseudomonas syringe DC3000 on single cell-type guard cells. We describe in detail the measurement of ROS production starting from sample preparation to data analysis by fluorescence intensity acquisition using ImageJ software. We discussed the problems faced while performing the experiment and addressed how to overcome them by providing specific guidelines to ensure high quality repeatable data.


Assuntos
Arabidopsis , Espécies Reativas de Oxigênio , Estresse Fisiológico , Espécies Reativas de Oxigênio/metabolismo , Arabidopsis/metabolismo , Arabidopsis/genética , Ácido Abscísico/metabolismo , Pseudomonas syringae
3.
J Lipid Res ; 65(7): 100570, 2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38795858

RESUMO

Glycosphingolipids (GSLs) are abundant glycolipids on cells and essential for cell recognition, adhesion, signal transduction, and so on. However, their lipid anchors are not long enough to cross the membrane bilayer. To transduce transmembrane signals, GSLs must interact with other membrane components, whereas such interactions are difficult to investigate. To overcome this difficulty, bifunctional derivatives of II3-ß-N-acetyl-D-galactosamine-GA2 (GalNAc-GA2) and ß-N-acetyl-D-glucosamine-ceramide (GlcNAc-Cer) were synthesized as probes to explore GSL-interacting membrane proteins in live cells. Both probes contain photoreactive diazirine in the lipid moiety, which can crosslink with proximal membrane proteins upon photoactivation, and clickable alkyne in the glycan to facilitate affinity tag addition for crosslinked protein pull-down and characterization. The synthesis is highlighted by the efficient assembly of simple glycolipid precursors followed by on-site lipid remodeling. These probes were employed to profile GSL-interacting membrane proteins in HEK293 cells. The GalNAc-GA2 probe revealed 312 distinct proteins, with GlcNAc-Cer probe-crosslinked proteins as controls, suggesting the potential influence of the glycan on GSL functions. Many of the proteins identified with the GalNAc-GA2 probe are associated with GSLs, and some have been validated as being specific to this probe. The versatile probe design and experimental protocols are anticipated to be widely applicable to GSL research.

4.
Biomater Adv ; 161: 213883, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38762928

RESUMO

Maintaining the viability of damaged pulp is critical in clinical dentistry. Pulp capping, by placing dental material over the exposed pulp, is a main approach to promote pulp-dentin healing and mineralized tissue formation. The dental materials are desired to impact on intricate physiological mechanisms in the healing process, including early regulation of inflammation, immunity, and cellular events. In this study, we developed an injectable dental pulp-derived decellularized matrix (DPM) hydrogel to modulate macrophage responses and promote dentin repair. The DPM derived from porcine dental pulp has high collagen retention and low DNA content. The DPM was solubilized by pepsin digestion (named p-DPM) and subsequently injected through a 25G needle to form hydrogel facilely at 37 °C. In vitro results demonstrated that the p-DPM induced the M2-polarization of macrophages and the migration, proliferation, and dentin differentiation of human dental pulp stem cells from deciduous teeth (SHEDs). In a mouse subcutaneous injection test, the p-DPM hydrogel was found to facilitate cell recruitment and M2 polarization during the early phase of implantation. Additionally, the acute pulp restoration in rat models proved that injectable p-DPM hydrogel as a pulp-capping agent had excellent efficacy in dentin regeneration. This study demonstrates that the DPM promotes dentin repair by modulating macrophage responses, and has a potential for pulp-capping applications in dental practice.


Assuntos
Polpa Dentária , Dentina , Hidrogéis , Macrófagos , Polpa Dentária/citologia , Polpa Dentária/efeitos dos fármacos , Animais , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Humanos , Dentina/efeitos dos fármacos , Dentina/química , Hidrogéis/química , Camundongos , Ratos , Matriz Extracelular Descelularizada/química , Matriz Extracelular Descelularizada/farmacologia , Suínos , Diferenciação Celular/efeitos dos fármacos , Regeneração/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células-Tronco/efeitos dos fármacos , Células-Tronco/citologia , Cicatrização/efeitos dos fármacos
5.
Int J Mol Sci ; 25(8)2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38674154

RESUMO

As global climate change continues, drought episodes have become increasingly frequent. Studying plant stress tolerance is urgently needed to ensure food security. The common ice plant is one of the model halophyte plants for plant stress biology research. This study aimed to investigate the functions of a newly discovered transcription factor, Homeobox 7 (HB7), from the ice plant in response to drought stress. An efficient Agrobacterium-mediated transformation method was established in the ice plant, where ectopic McHB7 expression may be sustained for four weeks. The McHB7 overexpression (OE) plants displayed drought tolerance, and the activities of redox enzymes and chlorophyll content in the OE plants were higher than the wild type. Quantitative proteomics revealed 1910 and 495 proteins significantly changed in the OE leaves compared to the wild type under the control and drought conditions, respectively. Most increased proteins were involved in the tricarboxylic acid cycle, photosynthesis, glycolysis, pyruvate metabolism, and oxidative phosphorylation pathways. Some were found to participate in abscisic acid signaling or response. Furthermore, the abscisic acid levels increased in the OE compared with the wild type. McHB7 was revealed to bind to the promoter motifs of Early Responsive to Dehydration genes and abscisic acid-responsive genes, and protein-protein interaction analysis revealed candidate proteins responsive to stresses and hormones (e.g., abscisic acid). To conclude, McHB7 may contribute to enhance plant drought tolerance through abscisic acid signaling.


Assuntos
Ácido Abscísico , Secas , Regulação da Expressão Gênica de Plantas , Transdução de Sinais , Estresse Fisiológico , Fatores de Transcrição , Ácido Abscísico/metabolismo , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas , Proteômica/métodos , Proteínas de Homeodomínio/metabolismo , Proteínas de Homeodomínio/genética , Resistência à Seca
6.
J Proteomics ; 299: 105145, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38431086

RESUMO

Mesembryanthemum crystallinum (common ice plant), a facultative CAM plant, shifts from C3 to CAM photosynthesis under salt stress, enhancing water use efficiency. Here we used transcriptomics, proteomics, and targeted metabolomics to profile molecular changes during the diel cycle of C3 to CAM transition. The results confirmed expected changes associated with CAM photosynthesis, starch biosynthesis and degradation, and glycolysis/gluconeogenesis. Importantly, they yielded new discoveries: 1) Transcripts displayed greater circadian regulation than proteins. 2) Oxidative phosphorylation and inositol methylation may play important roles in initiating the transition. 3) V-type H+-ATPases showed consistent transcriptional regulation, aiding in vacuolar malate uptake. 4) A protein phosphatase 2C, a major component in the ABA signaling pathway, may trigger the C3 to CAM transition. Our work highlights the potential molecular switches in the C3 to CAM transition, including the potential role of ABA signaling. SIGNIFICANCE: The common ice plant is a model facultative CAM plant, and under stress conditions it can shift from C3 to CAM photosynthesis within a three-day period. However, knowledge about the molecular changes during the transition and the molecular switches enabling the transition is lacking. Multi-omic analyses not only revealed the molecular changes during the transition, but also highlighted the importance of ABA signaling, inositol methylation, V-type H+-ATPase in initiating the shift. The findings may explain physiological changes and nocturnal stomatal opening, and inform future synthetic biology effort in improving crop water use efficiency and stress resilience.


Assuntos
Mesembryanthemum , Fotossíntese , Fotossíntese/fisiologia , Mesembryanthemum/metabolismo , Multiômica , Plantas , Inositol/metabolismo , Água/metabolismo
7.
Nanotechnology ; 35(23)2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38430571

RESUMO

In recent times, there has been a notable surge of interests in hafnia (HfO2)-based ferroelectrics, primarily due to their remarkable ferroelectric properties employed in ultra-thin configurations, alongside their compatibility with the conventional CMOS manufacturing process. In order to harness the full potential of HfO2-based films for high-performance non-volatile memory applications, it is imperative to enhance their ferroelectric characteristics and durability. This study introduces a straightforward approach aimed at augmenting the ferroelectric performance of HfxZr1-xO2(HZO) films deposited on silicon (Si) substrates through the engineering of oxygen vacancies (VO). The results of this endeavor demonstrate a significant enhancement in ferroelectric performance, characterized by a 2Pr value of 47µC cm-2and impressive endurance, enduring up to 108cycles under an 8 MV cm-1electric field without the need of a wake-up process. This marked improvement can be attributed to a dual-pronged approach, involving the incorporation of an Al2O3interlayer and the introduction of Al atoms into the HZO film. The Al2O3interlayer primarily serves to mitigate the presence of oxygen vacancies at the interface, while the introduction of Al dopants elevates the concentration of oxygen vacancies within the bulk material. This modulation of oxygen vacancy concentration proves instrumental in facilitating the formation of a ferroelectric o-III phase within the HZO-based films, thereby further augmenting their ferroelectric performance. This innovative and effective strategy offers an alternative avenue for enhancing the ferroelectric properties of materials characterized by a fluorite crystal structure.

8.
Clin Interv Aging ; 19: 529-538, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38525315

RESUMO

Purpose: To evaluate the performance of the Framingham cardiovascular risk score (FRS)/pooled cohort equations (PCE)/China prediction for atherosclerotic cardiovascular disease (ASCVD) risk (China-PAR model) in a prospective cohort of Chinese older adults. Patients and Methods: We assessed 717 older adults aged 75-85 years without ASCVD at the baseline from the Sichuan province of China. The participants were followed annually from 2011 to 2021. We obtained the participants' information through the medical records of physical examination and evaluated their 10-year ASCVD risk using FRS, PCE, and China-PAR. We further evaluated the predictive abilities of three assessment models. Results: During the 10-year follow-up, 206 participants developed ASCVD, with an incidence rate of 28.73%. The FRS and China-PAR moderately underestimated the risk of ASCVD (22.1% and 12.4%, respectively), but while PCE overestimated the risk (36.1%). FRS and China-PAR were found to underestimate the risk of ASCVD (26% and 63%, respectively) for men, while PCE overestimated the risk by 8%; For women, FRS and China-PAR were found to underestimate the risk of ASCVD (14% and 35%, respectively), while PCE overestimated the risk by 88%. Conclusion: The 10-year ASCVD risk was found to be overestimated by PCE. China-PAR had the most accurate predictions in women, while FRS was particularly well-calibrated in males. All three risk models have good discrimination, with FRS and PCE being well-calibrated in men and all three being well-calibrated in women. Therefore, accurate risk models are warranted to facilitate the prevention of ASCVD at the baseline among Chinese older adults.


Assuntos
Aterosclerose , Doenças Cardiovasculares , Masculino , Humanos , Feminino , Idoso , Fatores de Risco , Medição de Risco , Doenças Cardiovasculares/epidemiologia , Estudos Prospectivos , Aterosclerose/epidemiologia
9.
Cell ; 187(3): 609-623.e21, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38244548

RESUMO

Phosphatidic acid (PA) and reactive oxygen species (ROS) are crucial cellular messengers mediating diverse signaling processes in metazoans and plants. How PA homeostasis is tightly regulated and intertwined with ROS signaling upon immune elicitation remains elusive. We report here that Arabidopsis diacylglycerol kinase 5 (DGK5) regulates plant pattern-triggered immunity (PTI) and effector-triggered immunity (ETI). The pattern recognition receptor (PRR)-associated kinase BIK1 phosphorylates DGK5 at Ser-506, leading to a rapid PA burst and activation of plant immunity, whereas PRR-activated intracellular MPK4 phosphorylates DGK5 at Thr-446, which subsequently suppresses DGK5 activity and PA production, resulting in attenuated plant immunity. PA binds and stabilizes the NADPH oxidase RESPIRATORY BURST OXIDASE HOMOLOG D (RBOHD), regulating ROS production in plant PTI and ETI, and their potentiation. Our data indicate that distinct phosphorylation of DGK5 by PRR-activated BIK1 and MPK4 balances the homeostasis of cellular PA burst that regulates ROS generation in coordinating two branches of plant immunity.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Diacilglicerol Quinase , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Diacilglicerol Quinase/metabolismo , NADPH Oxidases/metabolismo , Ácidos Fosfatídicos/metabolismo , Fosforilação , Imunidade Vegetal , Proteínas Serina-Treonina Quinases/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Receptores de Reconhecimento de Padrão/metabolismo
10.
Trends Biochem Sci ; 49(3): 185-188, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-37884411

RESUMO

Post-transcriptional modifications of RNA (PRMs) and post-translational modifications of proteins (PTMs) are important regulatory mechanisms in biological processes and have many commonalities. However, the integration of these research areas is lacking. A recent discussion identified the priorities, areas of emphasis, and necessary technologies to advance and integrate these areas of study.


Assuntos
Processamento de Proteína Pós-Traducional , Proteínas , RNA
11.
Plant J ; 117(4): 1191-1205, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37997015

RESUMO

Polyploidy is an important evolutionary process throughout eukaryotes, particularly in flowering plants. Duplicated gene pairs (homoeologs) in allopolyploids provide additional genetic resources for changes in molecular, biochemical, and physiological mechanisms that result in evolutionary novelty. Therefore, understanding how divergent genomes and their regulatory networks reconcile is vital for unraveling the role of polyploidy in plant evolution. Here, we compared the leaf transcriptomes of recently formed natural allotetraploids (Tragopogon mirus and T. miscellus) and their diploid parents (T. porrifolius X T. dubius and T. pratensis X T. dubius, respectively). Analysis of 35 400 expressed loci showed a significantly higher level of transcriptomic additivity compared to old polyploids; only 22% were non-additively expressed in the polyploids, with 5.9% exhibiting transgressive expression (lower or higher expression in the polyploids than in the diploid parents). Among approximately 7400 common orthologous regions (COREs), most loci in both allopolyploids exhibited expression patterns that were vertically inherited from their diploid parents. However, 18% and 20.3% of the loci showed novel expression bias patterns in T. mirus and T. miscellus, respectively. The expression changes of 1500 COREs were explained by cis-regulatory divergence (the condition in which the two parental subgenomes do not interact) between the diploid parents, whereas only about 423 and 461 of the gene expression changes represent trans-effects (the two parental subgenomes interact) in T. mirus and T. miscellus, respectively. The low degree of both non-additivity and trans-effects on gene expression may present the ongoing evolutionary processes of the newly formed Tragopogon polyploids (~80-90 years).


Assuntos
Asteraceae , Tragopogon , Tragopogon/genética , Asteraceae/genética , Diploide , Poliploidia , Evolução Molecular , Genoma de Planta/genética
12.
Plant Commun ; 5(3): 100772, 2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-37990498

RESUMO

Modern agricultural systems are directly threatened by global climate change and the resulting freshwater crisis. A considerable challenge in the coming years will be to develop crops that can cope with the consequences of declining freshwater resources and changing temperatures. One approach to meeting this challenge may lie in our understanding of plant photosynthetic adaptations and water use efficiency. Plants from various taxa have evolved crassulacean acid metabolism (CAM), a water-conserving adaptation of photosynthetic carbon dioxide fixation that enables plants to thrive under semi-arid or seasonally drought-prone conditions. Although past research on CAM has led to a better understanding of the inner workings of plant resilience and adaptation to stress, successful introduction of this pathway into C3 or C4 plants has not been reported. The recent revolution in molecular, systems, and synthetic biology, as well as innovations in high-throughput data generation and mining, creates new opportunities to uncover the minimum genetic tool kit required to introduce CAM traits into drought-sensitive crops. Here, we propose four complementary research avenues to uncover this tool kit. First, genomes and computational methods should be used to improve understanding of the nature of variations that drive CAM evolution. Second, single-cell 'omics technologies offer the possibility for in-depth characterization of the mechanisms that trigger environmentally controlled CAM induction. Third, the rapid increase in new 'omics data enables a comprehensive, multimodal exploration of CAM. Finally, the expansion of functional genomics methods is paving the way for integration of CAM into farming systems.


Assuntos
Metabolismo Ácido das Crassuláceas , Resiliência Psicológica , Produtos Agrícolas/metabolismo , Agricultura , Água/metabolismo , Mudança Climática
13.
Nat Commun ; 14(1): 6848, 2023 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-37891163

RESUMO

Systemic acquired resistance (SAR) is a long-lasting broad-spectrum plant defense mechanism induced in distal systemic tissues by mobile signals generated at the primary infection site. Despite the discoveries of multiple potential mobile signals, how these signals cooperate to trigger downstream SAR signaling is unknown. Here, we show that endogenous extracellular nicotinamide adenine dinucleotide (phosphate) [eNAD(P)] accumulates systemically upon pathogen infection and that both eNAD(P) and the lectin receptor kinase (LecRK), LecRK-VI.2, are required in systemic tissues for the establishment of SAR. Moreover, putative mobile signals, e.g., N-hydroxypipecolic acid (NHP), trigger de novo systemic eNAD(P) accumulation largely through the respiratory burst oxidase homolog RBOHF-produced reactive oxygen species (ROS). Importantly, NHP-induced systemic immunity mainly depends on ROS, eNAD(P), LecRK-VI.2, and BAK1, indicating that NHP induces SAR primarily through the ROS-eNAD(P)-LecRK-VI.2/BAK1 signaling pathway. Our results suggest that mobile signals converge on eNAD(P) in systemic tissues to trigger SAR through LecRK-VI.2.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , NAD/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Doenças das Plantas , Regulação da Expressão Gênica de Plantas
14.
Micromachines (Basel) ; 14(10)2023 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-37893362

RESUMO

Chiral metasurfaces have garnered significant interest as an emerging field of metamaterials, primarily due to their exceptional capability to manipulate phase distributions at interfaces. However, the on-demand design of chiral metasurface structures remains a challenging task. To address this challenge, this paper introduces a deep learning-based network model for rapid calculation of chiral metasurface structure parameters. The network achieves a mean absolute error (MAE) of 0.025 and enables the design of chiral metasurface structures with a circular dichroism (CD) of 0.41 at a frequency of 1.169 THz. By changing the phase of the chiral metasurface, it is possible to produce not only a monofocal lens but also a multifocal lens. Well-designed chiral metasurface lenses allow us to control the number and position of focal points of the light field. This chiral metasurface, designed using deep learning, demonstrates great multifocal focus characteristics and holds great potential for a wide range of applications in sensing and holography.

15.
Int J Mol Sci ; 24(17)2023 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-37685878

RESUMO

Global climate change and population growth are persistently posing threats to natural resources (e.g., freshwater) and agricultural production. Crassulacean acid metabolism (CAM) evolved from C3 photosynthesis as an adaptive form of photosynthesis in hot and arid regions. It features the nocturnal opening of stomata for CO2 assimilation, diurnal closure of stomata for water conservation, and high water-use efficiency. To cope with global climate challenges, the CAM mechanism has attracted renewed attention. Facultative CAM is a specialized form of CAM that normally employs C3 or C4 photosynthesis but can shift to CAM under stress conditions. It not only serves as a model for studying the molecular mechanisms underlying the CAM evolution, but also provides a plausible solution for creating stress-resilient crops with facultative CAM traits. This review mainly discusses the recent research effort in defining the C3 to CAM transition of facultative CAM plants, and highlights challenges and future directions in this important research area with great application potential.


Assuntos
Metabolismo Ácido das Crassuláceas , Fotossíntese , Agricultura , Mudança Climática , Produtos Agrícolas
16.
Micromachines (Basel) ; 14(4)2023 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-37421022

RESUMO

Chiral metasurfaces have great influence on the development of holography. Nonetheless, it is still challenging to design chiral metasurface structures on demand. As a machine learning method, deep learning has been applied to design metasurface in recent years. This work uses a deep neural network with a mean absolute error (MAE) of 0.03 to inverse design chiral metasurface. With the help of this approach, a chiral metasurface with circular dichroism (CD) values higher than 0.4 is designed. The static chirality of the metasurface and the hologram with an image distance of 3000 µm are characterized. The imaging results are clearly visible and demonstrate the feasibility of our inverse design approach.

17.
mBio ; 14(4): e0085223, 2023 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-37458473

RESUMO

Nucleases are strictly regulated and often localized in the cell to avoid the uncontrolled degradation of DNA and RNA. Here, a new type of nuclease complex, composed of RecJ3, RecJ4, and aRNase J, was identified through its ATP-dependent association with the ubiquitin-like SAMP1 and AAA-ATPase Cdc48a. The complex was discovered in Haloferax volcanii, an archaeon lacking an RNA exosome. Genetic analysis revealed aRNase J to be essential and RecJ3, RecJ4, and Cdc48a to function in the recovery from DNA damage including genotoxic agents that generate double-strand breaks. The RecJ3:RecJ4:aRNase J complex (isolated in 2:2:1 stoichiometry) functioned primarily as a 3'-5' exonuclease in hydrolyzing RNA and ssDNA, with the mechanism non-processive for ssDNA. aRNase J could also be purified as a homodimer that catalyzed endoribonuclease activity and, thus, was not restricted to the 5'-3' exonuclease activity typical of aRNase J homologs. Moreover, RecJ3 and RecJ4 could be purified as a 560-kDa subcomplex in equimolar subunit ratio with nuclease activities mirroring the full RecJ3/4-aRNase J complex. These findings prompted reconstitution assays that suggested RecJ3/4 could suppress, alter, and/or outcompete the nuclease activities of aRNase J. Based on the phenotypic results, this control mechanism of aRNase J by RecJ3/4 is not necessary for cell growth but instead appears important for DNA repair. IMPORTANCE Nucleases are critical for various cellular processes including DNA replication and repair. Here, a dynamic type of nuclease complex is newly identified in the archaeon Haloferax volcanii, which is missing the canonical RNA exosome. The complex, composed of RecJ3, RecJ4, and aRNase J, functions primarily as a 3'-5' exonuclease and was discovered through its ATP-dependent association with the ubiquitin-like SAMP1 and Cdc48a. aRNase J alone forms a homodimer that has endonuclease function and, thus, is not restricted to 5'-3' exonuclease activity typical of other aRNase J enzymes. RecJ3/4 appears to suppress, alter, and/or outcompete the nuclease activities of aRNase J. While aRNase J is essential for growth, RecJ3/4, Cdc48a, and SAMPs are important for recovery against DNA damage. These biological distinctions may correlate with the regulated nuclease activity of aRNase J in the RecJ3/4-aRNaseJ complex.


Assuntos
Haloferax volcanii , Haloferax volcanii/genética , Complexo Multienzimático de Ribonucleases do Exossomo/genética , Complexo Multienzimático de Ribonucleases do Exossomo/metabolismo , Fosfodiesterase I/genética , Fosfodiesterase I/metabolismo , Ubiquitina/metabolismo , Dano ao DNA , Exonucleases/genética , Exonucleases/metabolismo , Endonucleases/genética , Endonucleases/metabolismo , RNA/metabolismo , Trifosfato de Adenosina/metabolismo
18.
Methods Mol Biol ; 2690: 137-147, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37450145

RESUMO

Identification of protein-protein interactions (PPIs) and protein kinase substrates is fundamental for understanding how proteins exert biological functions with their partners and targets. However, it is still technically challenging, especially for transient and weak interactions involved in most cellular processes. The proximity-tagging systems enable capturing snapshots of both stable and transient PPIs. In this chapter, we describe in detail the methodology of a novel proximity-based labeling approach, PUP-IT (pupylation-based interaction tagging), to identify PPIs using a protoplast transient expression system. We have successfully identified potential kinase substrates by targeted screening and tandem mass spectrometry analysis.


Assuntos
Proteínas de Bactérias , Células Vegetais , Células Vegetais/metabolismo , Proteínas de Bactérias/metabolismo , Espectrometria de Massas em Tandem
19.
Front Plant Sci ; 14: 1185440, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37332716

RESUMO

Sugar beet is one of the most important sugar crops in the world. It contributes greatly to the global sugar production, but salt stress negatively affects the crop yield. WD40 proteins play important roles in plant growth and response to abiotic stresses through their involvement in a variety of biological processes, such as signal transduction, histone modification, ubiquitination, and RNA processing. The WD40 protein family has been well-studied in Arabidopsis thaliana, rice and other plants, but the systematic analysis of the sugar beet WD40 proteins has not been reported. In this study, a total of 177 BvWD40 proteins were identified from the sugar beet genome, and their evolutionary characteristics, protein structure, gene structure, protein interaction network and gene ontology were systematically analyzed to understand their evolution and function. Meanwhile, the expression patterns of BvWD40s under salt stress were characterized, and a BvWD40-82 gene was hypothesized as a salt-tolerant candidate gene. Its function was further characterized using molecular and genetic methods. The result showed that BvWD40-82 enhanced salt stress tolerance in transgenic Arabidopsis seedlings by increasing the contents of osmolytes and antioxidant enzyme activities, maintaining intracellular ion homeostasis and increasing the expression of genes related to SOS and ABA pathways. The result has laid a foundation for further mechanistic study of the BvWD40 genes in sugar beet tolerance to salt stress, and it may inform biotechnological applications in improving crop stress resilience.

20.
Antioxidants (Basel) ; 12(6)2023 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-37371933

RESUMO

Oxidative stress adaptation strategies are important to cell function and are linked to cardiac, neurodegenerative disease, and cancer. Representatives of the Archaea domain are used as model organisms based on their extreme tolerance to oxidants and close evolutionary relationship with eukaryotes. A study of the halophilic archaeon Haloferax volcanii reveals lysine acetylation to be associated with oxidative stress responses. The strong oxidant hypochlorite: (i) stimulates an increase in lysine acetyltransferase HvPat2 to HvPat1 abundance ratios and (ii) selects for lysine deacetylase sir2 mutants. Here we report the dynamic occupancy of the lysine acetylome of glycerol-grown H. volcanii as it shifts in profile in response to hypochlorite. These findings are revealed by the: (1) quantitative multiplex proteomics of the SILAC-compatible parent and Δsir2 mutant strains and (2) label-free proteomics of H26 'wild type' cells. The results show that lysine acetylation is associated with key biological processes including DNA topology, central metabolism, cobalamin biosynthesis, and translation. Lysine acetylation targets are found conserved across species. Moreover, lysine residues modified by acetylation and ubiquitin-like sampylation are identified suggesting post-translational modification (PTM) crosstalk. Overall, the results of this study expand the current knowledge of lysine acetylation in Archaea, with the long-term goal to provide a balanced evolutionary perspective of PTM systems in living organisms.

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