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Mahieu CI, Mancini AG, Vikram EP, Planells-Palop V, Joseph NM, Tward AD. ORAOV1, CCND1, and MIR548K Are the Driver Oncogenes of the 11q13 Amplicon in Squamous Cell Carcinoma. Mol Cancer Res 2024; 22:152-168. [PMID: 37930255 PMCID: PMC10831340 DOI: 10.1158/1541-7786.mcr-23-0746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 09/29/2023] [Accepted: 11/02/2023] [Indexed: 11/07/2023]
Abstract
11q13 amplification is a frequent event in human cancer and in particular in squamous cell carcinomas (SCC). Despite almost invariably spanning 10 genes, it is unclear which genetic components of the amplicon are the key driver events in SCC. A combination of computational, in vitro, ex vivo, and in vivo models leveraging efficient primary human keratinocyte genome editing by Cas9-RNP electroporation, identified ORAOV1, CCND1, and MIR548K as the critical drivers of the amplicon in head and neck SCC. CCND1 amplification drives the cell cycle in a CDK4/6/RB1-independent fashion and may confer a novel dependency on RRM2. MIR548K contributes to epithelial-mesenchymal transition. Finally, we identify ORAOV1 as an oncogene that acts likely via its ability to modulate reactive oxygen species. Thus, the 11q13 amplicon drives SCC through at least three independent genetic elements and suggests therapeutic targets for this morbid and lethal disease. IMPLICATIONS This work demonstrates novel mechanisms and ways to target these mechanisms underlying the most common amplification in squamous cell carcinoma, one of the most prevalent and deadly forms of human cancer.
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Affiliation(s)
- Céline I. Mahieu
- Department of Otolaryngology, Head and Neck Surgery, University of California San Francisco, San Francisco, Calfornia
| | | | - Ellee P. Vikram
- Department of Otolaryngology, Head and Neck Surgery, University of California San Francisco, San Francisco, Calfornia
| | - Vicente Planells-Palop
- Department of Otolaryngology, Head and Neck Surgery, University of California San Francisco, San Francisco, Calfornia
| | - Nancy M. Joseph
- Department of Pathology, University of California San Francisco, San Francisco, California
| | - Aaron D. Tward
- Department of Otolaryngology, Head and Neck Surgery, University of California San Francisco, San Francisco, Calfornia
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Ozfidan-Konakci C, Yildiztugay E, Arikan B, Alp-Turgut FN, Turan M, Cavusoglu H, Sakalak H. Responses of individual and combined polystyrene and polymethyl methacrylate nanoplastics on hormonal content, fluorescence/photochemistry of chlorophylls and ROS scavenging capacity in Lemna minor under arsenic-induced oxidative stress. Free Radic Biol Med 2023; 196:93-107. [PMID: 36657731 DOI: 10.1016/j.freeradbiomed.2023.01.015] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 12/12/2022] [Accepted: 01/12/2023] [Indexed: 01/18/2023]
Abstract
Nanoplastics alter the adverse impacts of hazardous contaminants such as heavy metals by changing their adsorption and accumulation. Few findings are available on the interaction between nanoplastic and heavy metals in plants. However, there is no report on the mechanisms for removing metal stress-mediated oxidative damage by the combination treatments of nanoplastics. To address this lack of information, polystyrene nanoplastic (PS, 100 mg L-1) and polymethyl methacrylate (PMMA, 100 mg L-1) were hydroponically applied to Lemna minor exposed to arsenate (As, 100 μM) for 7 days. PS or PMMA caused a reduction in the contents of N, P, K, Ca, Mg and Mn, but the improved contents were detected in the presence of PS or PMMA plus As stress. The hormone contents (auxin, gibberellic acid, cytokinin, salicylic acid and jasmonic acid) reduced by stress were re-arranged through PS or PMMA applications. Based on chlorophyll efficiency, fluorescence kinetics and performance of PSII, the impaired photosynthesis by As stress was improved via PS or PMMA applications. This alleviation did not continue under the combined form of PS and PMMA in As-applied plants. All analyzed antioxidant activity (superoxide dismutase (SOD), catalase (CAT), peroxidase (POX), ascorbate peroxidase (APX), glutathione reductase (GR), glutathione S-transferase (GST), glutathione peroxidase (GPX), monodehydroascorbate reductase (MDHAR) and dehydroascorbate reductase (DHAR)) decreased or unchanged under As, PS or PMMA. Due to the inactivation of the defense system, L. minor had high levels of hydrogen peroxide (H2O2) and thiobarbituric acid reactive substances (TBARS), showing lipid peroxidation. After As toxicity, induvial applications of PS or PMMA indicated the activated enzyme capacity (SOD, POX, GST and GPX) and upregulated AsA/DHA, GSH/GSSG and redox state of GSH, which facilitated the removal of radical accumulation. The efficiency of the antioxidant system in As + PS + PMMA-applied L. minor was not enough to remove damage induced by As stress; hereby, TBARS and H2O2 contents were similar to the As-treated group. Our findings from alone or combined application of PS and PMMA provide new information to advance the tolerance mechanism against As exposure in L. minor.
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Affiliation(s)
- Ceyda Ozfidan-Konakci
- Department of Molecular Biology and Genetics, Faculty of Science, Necmettin Erbakan University, Meram, 42090, Konya, Turkey.
| | - Evren Yildiztugay
- Department of Biotechnology, Faculty of Science, Selcuk University, Selcuklu, 42130, Konya, Turkey.
| | - Busra Arikan
- Department of Biotechnology, Faculty of Science, Selcuk University, Selcuklu, 42130, Konya, Turkey.
| | - Fatma Nur Alp-Turgut
- Department of Biotechnology, Faculty of Science, Selcuk University, Selcuklu, 42130, Konya, Turkey.
| | - Metin Turan
- Department of Agricultural Trade and Management, Faculty of Economy and Administrative Sciences, Yeditepe University, 34755, Istanbul, Turkey.
| | - Halit Cavusoglu
- Department of Physics, Faculty of Science, Selcuk University, Selcuklu, 42130, Konya, Turkey.
| | - Huseyin Sakalak
- Graduate School of Natural and Applied Sciences, Nanotechnology and Advanced Materials, Selcuk University, Selcuklu, 42130, Konya, Turkey.
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Song Q, Wang X, Liu Y, Brestic M, Yang X. StLTO1, a lumen thiol oxidoreductase in Solanum tuberosum L., enhances the cold resistance of potato plants. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2022; 325:111481. [PMID: 36181944 DOI: 10.1016/j.plantsci.2022.111481] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Revised: 09/19/2022] [Accepted: 09/26/2022] [Indexed: 06/16/2023]
Abstract
Cold stress reduces plant photosynthesis and increases the accumulation of reactive oxygen species (ROS) in plants, thereby dramatically affecting plant growth, crop productivity and quality. Here, we report that lumen thiol oxidoreductase 1 (StLTO1), a vitamin K epoxide reductase (VKOR)-like protein in the thylakoid membrane of Solanum tuberosum L., enhances the cold tolerance of potato plants. Under normal conditions, overexpression of StLTO1 in plants promoted plant growth. In addition, potato plants overexpressing StLTO1 displayed enhanced photosynthetic capacity and increased capacity for scavenging ROS compared to StLTO1 knockdown and wild-type potato plants under cold conditions. Overexpression of StLTO1 in potato plants also improved cold-regulated (COR) gene expression after cold stress. Our results suggest that StLTO1 acts as a positive regulator of cold resistance in potato plants.
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Affiliation(s)
- Qiping Song
- College of Life Science, State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, Shandong Agricultural University, Taian, 271018, China
| | - Xipan Wang
- College of Life Science, State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, Shandong Agricultural University, Taian, 271018, China
| | - Yang Liu
- College of Life Science, State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, Shandong Agricultural University, Taian, 271018, China
| | - Marian Brestic
- Department of Plant Physiology, Slovak University of Agriculture, Tr. A. Hlinku 2, 949 76 Nitra, Slovak Republic
| | - Xinghong Yang
- College of Life Science, State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, Shandong Agricultural University, Taian, 271018, China.
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Foyer CH, Hanke G. ROS production and signalling in chloroplasts: cornerstones and evolving concepts. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2022; 111:642-661. [PMID: 35665548 PMCID: PMC9545066 DOI: 10.1111/tpj.15856] [Citation(s) in RCA: 80] [Impact Index Per Article: 40.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 05/27/2022] [Accepted: 06/02/2022] [Indexed: 05/05/2023]
Abstract
Reactive oxygen species (ROS) such as singlet oxygen, superoxide (O2●- ) and hydrogen peroxide (H2 O2 ) are the markers of living cells. Oxygenic photosynthesis produces ROS in abundance, which act as a readout of a functional electron transport system and metabolism. The concept that photosynthetic ROS production is a major driving force in chloroplast to nucleus retrograde signalling is embedded in the literature, as is the role of chloroplasts as environmental sensors. The different complexes and components of the photosynthetic electron transport chain (PETC) regulate O2●- production in relation to light energy availability and the redox state of the stromal Cys-based redox systems. All of the ROS generated in chloroplasts have the potential to act as signals and there are many sulphhydryl-containing proteins and peptides in chloroplasts that have the potential to act as H2 O2 sensors and function in signal transduction. While ROS may directly move out of the chloroplasts to other cellular compartments, ROS signalling pathways can only be triggered if appropriate ROS-sensing proteins are present at or near the site of ROS production. Chloroplast antioxidant systems serve either to propagate these signals or to remove excess ROS that cannot effectively be harnessed in signalling. The key challenge is to understand how regulated ROS delivery from the PETC to the Cys-based redox machinery is organised to transmit redox signals from the environment to the nucleus. Redox changes associated with stromal carbohydrate metabolism also play a key role in chloroplast signalling pathways.
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Affiliation(s)
- Christine H. Foyer
- School of Biosciences, College of Life and Environmental SciencesUniversity of BirminghamEdgbastonB15 2TTUK
| | - Guy Hanke
- School of Biological and Chemical SciencesQueen Mary University of LondonMile End RoadLondonE1 4NSUK
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Ponnu J. Tuning the transitions: a thioredoxin regulates STATE TRANSITION 7 kinase during photoacclimation. PLANT PHYSIOLOGY 2021; 186:814-815. [PMID: 33760058 PMCID: PMC8195497 DOI: 10.1093/plphys/kiab128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 03/08/2021] [Indexed: 06/12/2023]
Affiliation(s)
- Jathish Ponnu
- Institute for Plant Sciences, Cologne Biocenter, University of Cologne, Zülpicher Str. 47b, 50674 Cologne, Germany
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Wu J, Rong L, Lin W, Kong L, Wei D, Zhang L, Rochaix JD, Xu X. Functional redox links between lumen thiol oxidoreductase1 and serine/threonine-protein kinase STN7. PLANT PHYSIOLOGY 2021; 186:964-976. [PMID: 33620491 PMCID: PMC8195503 DOI: 10.1093/plphys/kiab091] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 02/11/2021] [Indexed: 05/07/2023]
Abstract
In response to changing light quantity and quality, photosynthetic organisms perform state transitions, a process which optimizes photosynthetic yield and mitigates photo-damage. The serine/threonine-protein kinase STN7 phosphorylates the light-harvesting complex of photosystem II (PSII; light-harvesting complex II), which then migrates from PSII to photosystem I (PSI), thereby rebalancing the light excitation energy between the photosystems and restoring the redox poise of the photosynthetic electron transport chain. Two conserved cysteines forming intra- or intermolecular disulfide bonds in the lumenal domain (LD) of STN7 are essential for the kinase activity although it is still unknown how activation of the kinase is regulated. In this study, we show lumen thiol oxidoreductase 1 (LTO1) is co-expressed with STN7 in Arabidopsis (Arabidopsis thaliana) and interacts with the LD of STN7 in vitro and in vivo. LTO1 contains thioredoxin (TRX)-like and vitamin K epoxide reductase domains which are related to the disulfide-bond formation system in bacteria. We further show that the TRX-like domain of LTO1 is able to oxidize the conserved lumenal cysteines of STN7 in vitro. In addition, loss of LTO1 affects the kinase activity of STN7 in Arabidopsis. Based on these results, we propose that LTO1 helps to maintain STN7 in an oxidized active state in state 2 through redox interactions between the lumenal cysteines of STN7 and LTO1.
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Affiliation(s)
- Jianghao Wu
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Liwei Rong
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Weijun Lin
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lingxi Kong
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Dengjie Wei
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lixin Zhang
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng 475004, China
| | - Jean-David Rochaix
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng 475004, China
- Department of Molecular Biology, University of Geneva, Geneva 1211, Switzerland
- Department of Plant Biology, University of Geneva, Geneva 1211, Switzerland
| | - Xiumei Xu
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng 475004, China
- Author for communication:
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Hashemi SA, Kyani A, Bathaie SZ. The in silico mechanism of hVKOR interaction with acetaminophen and its metabolite, as well as N-acetyl cysteine: caution on application in COVID-19 patients. J Biomol Struct Dyn 2021; 40:8274-8285. [PMID: 33879035 PMCID: PMC8074654 DOI: 10.1080/07391102.2021.1910570] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Acetaminophen and N-acetyl cysteine (NAC) are being used as supportive care in patients suffering from coronavirus disease 2019 (COVID-19). The coagulopathy and cerebral hemorrhage have been recently reported in these patients. Prolonged acetaminophen use increases the international normalized ratio (INR) and the risk of bleeding among patients taking anti-coagulants. Inhibition of vitamin K epoxide reductase (VKOR) by acetaminophen and NAC in chronic applications has been reported, however, detailed knowledge of the molecular mechanism and binding sites are not clear. Herein, we built the homology model of human VKOR (hVKOR) using ITASSER server, confirmed, and applied it for docking analysis of its interaction with acetaminophen and its metabolite, N-acetyl-p-benzoquinone imine (NAPQI), and NAC. We also calculated the lipophilicity and predicted the blood-brain-barrier (BBB) permeation of NAPQI by Swiss ADME. Our analysis showed that NAPQI and NAC, but not acetaminophen, bind strongly to the similar sites in hVKOR via both hydrogen and van der Waals bonding; particularly with Cys135. Thus, it interrupted the vitamin K reducing electron transfer pathway. Further, molecular dynamic (MD) simulation study revealed that the interactions of the ligands with hVKOR are stable. In conclusion, our analysis shed a light on the molecular mechanism of acetaminophen-induced coagulopathy previously reported in some clinical cases with chronic acetaminophen use. Furthermore, considering the anti-coagulopathy of NAPQI and NAC but not acetaminophen, the BBB permeation potency of these agents, and the risk of coagulopathy in COVID-19, we suggest a regular prothrombin time (PT) and INR monitoring of these patients taking acetaminophen and/or NAC.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- S Ali Hashemi
- Department of Clinical Biochemistry, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.,Department of Laboratory Sciences, Chalus Branch, Islamic Azad University, Chalous, Iran
| | - Armita Kyani
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, MI, USA
| | - S Zahra Bathaie
- Department of Clinical Biochemistry, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
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Meyer AJ, Riemer J, Rouhier N. Oxidative protein folding: state-of-the-art and current avenues of research in plants. THE NEW PHYTOLOGIST 2019; 221:1230-1246. [PMID: 30230547 DOI: 10.1111/nph.15436] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2018] [Accepted: 08/01/2018] [Indexed: 06/08/2023]
Abstract
Contents Summary 1230 I. Introduction 1230 II. Formation and isomerization of disulfides in the ER and the Golgi apparatus 1231 III. The disulfide relay in the mitochondrial intermembrane space: why are plants different? 1236 IV. Disulfide bond formation on luminal proteins in thylakoids 1240 V. Conclusion 1242 Acknowledgements 1242 References 1242 SUMMARY: Disulfide bonds are post-translational modifications crucial for the structure and function of thousands of proteins. Their formation and isomerization, referred to as oxidative folding, require specific protein machineries found in oxidizing subcellular compartments, namely the endoplasmic reticulum and the associated endomembrane system, the intermembrane space of mitochondria and the thylakoid lumen of chloroplasts. At least one protein component is required for transferring electrons from substrate proteins to an acceptor that is usually molecular oxygen. For oxidation reactions, incoming reduced substrates are oxidized by thiol-oxidoreductase proteins (or domains in case of chimeric proteins), which are usually themselves oxidized by a single thiol oxidase, the enzyme generating disulfide bonds de novo. By contrast, the description of the molecular actors and pathways involved in proofreading and isomerization of misfolded proteins, which require a tightly controlled redox balance, lags behind. Herein we provide a general overview of the knowledge acquired on the systems responsible for oxidative protein folding in photosynthetic organisms, highlighting their particularities compared to other eukaryotes. Current research challenges are discussed including the importance and specificity of these oxidation systems in the context of the existence of reducing systems in the same compartments.
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Affiliation(s)
- Andreas J Meyer
- INRES-Chemical Signalling, University of Bonn, 53113, Bonn, Germany
| | - Jan Riemer
- Institute of Biochemistry, University of Cologne, 50674, Cologne, Germany
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Zhou C, Zhu L, Xie Y, Li F, Xiao X, Ma Z, Wang J. Bacillus licheniformis SA03 Confers Increased Saline-Alkaline Tolerance in Chrysanthemum Plants by Induction of Abscisic Acid Accumulation. FRONTIERS IN PLANT SCIENCE 2017; 8:1143. [PMID: 28706529 PMCID: PMC5489591 DOI: 10.3389/fpls.2017.01143] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2017] [Accepted: 06/14/2017] [Indexed: 05/04/2023]
Abstract
Soil saline-alkalization is a major abiotic stress that leads to low iron (Fe) availability and high toxicity of sodium ions (Na+) for plants. It has recently been shown that plant growth promoting rhizobacteria (PGPR) can enhance the ability of plants to tolerate multiple abiotic stresses such as drought, salinity, and nutrient deficiency. However, the possible involvement of PGPR in improving saline-alkaline tolerance of plants and the underlying mechanisms remain largely unknown. In this study, we investigated the effects of Bacillus licheniformis (strain SA03) on the growth of Chrysanthemum plants under saline-alkaline conditions. Our results revealed that inoculation with SA03 alleviated saline-alkaline stress in plants with increased survival rates, photosynthesis and biomass. The inoculated plants accumulated more Fe and lower Na+ concentrations under saline-alkaline stress compared with the non-inoculated plants. RNA-Sequencing analyses further revealed that SA03 significantly activated abiotic stress- and Fe acquisition-related pathways in the stress-treated plants. However, SA03 failed to increase saline-alkaline tolerance in plants when cellular abscisic acid (ABA) and nitric oxide (NO) synthesis were inhibited by treatment with fluridone (FLU) and 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (c-PTIO), respectively. Importantly, we also found that NO acted downstream of SA03-induced ABA to activate a series of adaptive responses in host plants under saline-alkaline stress. These findings demonstrated the potential roles of B. licheniformis SA03 in enhancing saline-alkaline tolerance of plants and highlighted the intricate integration of microbial signaling in regulating cellular Fe and Na+ accumulation.
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Affiliation(s)
- Cheng Zhou
- Key Laboratory of Bio-organic Fertilizer Creation, Ministry of Agriculture, Anhui Science and Technology UniversityBengbu, China
- School of Life Science and Technology, Tongji UniversityShanghai, China
| | - Lin Zhu
- School of Life Science and Technology, Tongji UniversityShanghai, China
| | - Yue Xie
- Key Laboratory of Bio-organic Fertilizer Creation, Ministry of Agriculture, Anhui Science and Technology UniversityBengbu, China
| | - Feiyue Li
- Key Laboratory of Bio-organic Fertilizer Creation, Ministry of Agriculture, Anhui Science and Technology UniversityBengbu, China
| | - Xin Xiao
- Key Laboratory of Bio-organic Fertilizer Creation, Ministry of Agriculture, Anhui Science and Technology UniversityBengbu, China
| | - Zhongyou Ma
- Key Laboratory of Bio-organic Fertilizer Creation, Ministry of Agriculture, Anhui Science and Technology UniversityBengbu, China
| | - Jianfei Wang
- Key Laboratory of Bio-organic Fertilizer Creation, Ministry of Agriculture, Anhui Science and Technology UniversityBengbu, China
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Enhanced Iron and Selenium Uptake in Plants by Volatile Emissions of Bacillus amyloliquefaciens (BF06). APPLIED SCIENCES-BASEL 2017. [DOI: 10.3390/app7010085] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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11
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Shapiguzov A, Chai X, Fucile G, Longoni P, Zhang L, Rochaix JD. Activation of the Stt7/STN7 Kinase through Dynamic Interactions with the Cytochrome b6f Complex. PLANT PHYSIOLOGY 2016; 171:82-92. [PMID: 26941194 PMCID: PMC4854690 DOI: 10.1104/pp.15.01893] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 03/02/2016] [Indexed: 05/20/2023]
Abstract
Photosynthetic organisms have the ability to adapt to changes in light quality by readjusting the cross sections of the light-harvesting systems of photosystem II (PSII) and photosystem I (PSI). This process, called state transitions, maintains the redox poise of the photosynthetic electron transfer chain and ensures a high photosynthetic yield when light is limiting. It is mediated by the Stt7/STN7 protein kinase, which is activated through the cytochrome b6f complex upon reduction of the plastoquinone pool. Its probable major substrate, the light-harvesting complex of PSII, once phosphorylated, dissociates from PSII and docks to PSI, thereby restoring the balance of absorbed light excitation energy between the two photosystems. Although the kinase is known to be inactivated under high-light intensities, the molecular mechanisms governing its regulation remain unknown. In this study we monitored the redox state of a conserved and essential Cys pair of the Stt7/STN7 kinase and show that it forms a disulfide bridge. We could not detect any change in the redox state of these Cys during state transitions and high-light treatment. It is only after prolonged anaerobiosis that this disulfide bridge is reduced. It is likely to be mainly intramolecular, although kinase activation may involve a transient covalently linked kinase dimer with two intermolecular disulfide bonds. Using the yeast two-hybrid system, we have mapped one interaction site of the kinase on the Rieske protein of the cytochrome b6f complex.
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Affiliation(s)
- Alexey Shapiguzov
- Departments of Molecular Biology and Plant Biology, University of Geneva, Geneva, Switzerland (A.S.); and Photosynthesis Research Center, Institute of Botany, Chinese Academy of Sciences, Beijing, China (X.C., G.F., P.L., L.Z., J.-D.R.)
| | - Xin Chai
- Departments of Molecular Biology and Plant Biology, University of Geneva, Geneva, Switzerland (A.S.); and Photosynthesis Research Center, Institute of Botany, Chinese Academy of Sciences, Beijing, China (X.C., G.F., P.L., L.Z., J.-D.R.)
| | - Geoffrey Fucile
- Departments of Molecular Biology and Plant Biology, University of Geneva, Geneva, Switzerland (A.S.); and Photosynthesis Research Center, Institute of Botany, Chinese Academy of Sciences, Beijing, China (X.C., G.F., P.L., L.Z., J.-D.R.)
| | - Paolo Longoni
- Departments of Molecular Biology and Plant Biology, University of Geneva, Geneva, Switzerland (A.S.); and Photosynthesis Research Center, Institute of Botany, Chinese Academy of Sciences, Beijing, China (X.C., G.F., P.L., L.Z., J.-D.R.)
| | - Lixin Zhang
- Departments of Molecular Biology and Plant Biology, University of Geneva, Geneva, Switzerland (A.S.); and Photosynthesis Research Center, Institute of Botany, Chinese Academy of Sciences, Beijing, China (X.C., G.F., P.L., L.Z., J.-D.R.)
| | - Jean-David Rochaix
- Departments of Molecular Biology and Plant Biology, University of Geneva, Geneva, Switzerland (A.S.); and Photosynthesis Research Center, Institute of Botany, Chinese Academy of Sciences, Beijing, China (X.C., G.F., P.L., L.Z., J.-D.R.)
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Structural Modeling Insights into Human VKORC1 Phenotypes. Nutrients 2015; 7:6837-51. [PMID: 26287237 PMCID: PMC4555152 DOI: 10.3390/nu7085313] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Revised: 08/03/2015] [Accepted: 08/06/2015] [Indexed: 11/17/2022] Open
Abstract
Vitamin K 2,3-epoxide reductase complex subunit 1 (VKORC1) catalyses the reduction of vitamin K and its 2,3-epoxide essential to sustain γ-carboxylation of vitamin K-dependent proteins. Two different phenotypes are associated with mutations in human VKORC1. The majority of mutations cause resistance to 4-hydroxycoumarin- and indandione-based vitamin K antagonists (VKA) used in the prevention and therapy of thromboembolism. Patients with these mutations require greater doses of VKA for stable anticoagulation than patients without mutations. The second phenotype, a very rare autosomal-recessive bleeding disorder caused by combined deficiency of vitamin K dependent clotting factors type 2 (VKCFD2) arises from a homozygous Arg98Trp mutation. The bleeding phenotype can be corrected by vitamin K administration. Here, we summarize published experimental data and in silico modeling results in order to rationalize the mechanisms of VKA resistance and VKCFD2.
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