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Molecular plant 2014年第7期7卷 1252-1255页

作者： juan manuel pérez-ruiz manuel Guinea Leonor puerto-Galán Francisco Javier Cejudo Instituto de Bioquímica Vegetal y Fotosíntesis Universidad de Sevilla-Consejo Superior de Investigaciones Científicas 41092-Sevilla Spain Umea plant Science Centre Department of Plant Physiology Umea University S-901 87 Umea Sweden

Dear Editor, The synthesis of tetrapyrroles, including chlorophylls, is central for chloroplast function. The metabolic pathway of tetrapyrrole biosynthesis in Arabidopsis is initiated with the formation of amino levulinic acid （ALA）, which is con- verted by a series of common reactions to protoporphy- tin IX （proto IX）（Tanaka et al., 2011）. Then the pathway diverges into two branches： the synthesis of heme/bilin and chlorophylls. The insertion of Mg2＋ into proto IX, cata- lyzed by Mg-chelatase, is the first committed reaction of the chlorophyll branch and is considered a key step for the regulation of the whole pathway. Mg-chelatase is a het- erotrimeric enzyme composed of subunits CHLI, CHLD, and CHLH, the reaction mechanism of which has been estab- lished. It is a two-step process consisting in the Mg-ATp- dependent activation of the enzyme, which implies the formation of a ternary complex of subunits CHLI and CHLD with ATp-Mg2＋, and Mg2＋ chelation, which is catalyzed by CHLH driven by ATp hydrolysis, CHLI providing ATpase activity to the complex （Tanaka et al., 2011）. In Arabidopsis, CHLH and CHLD are encoded by single genes, whereas two genes, CHLI-I and CHLI-2, encode the two isoforms of CHLI.

关键词： synthesis of tetrapyrroles chlorophylls Arabidopsis

The Quaternary Structure of NADpH Thioredoxin Reductase C Is Redox-Sensitive

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Molecular plant 2009年第3期2卷 457-467页

作者： juan manuel pérez-ruiz Maricruz Gonzalez Maria Cristina Spinola Luisa Maria Sandalio Francisco Javier Cejudo Instituto de Bioqulmica Vegetal y Fotoslntesis Universidad de Sevilla y CSIC Avda Américo Vespucio 49 41092-Sevilla Spain present address: plant Biology Laboratory The Salk Institute 10010 N. Torrey Pines Rd La Jolla CA 92037 USA Estacion Experimental del Zaidin CSIC C/Prof Albareda 1 18008-Granada Spain

NADpH thioredoxin reductase C （NTRC） is a chloroplast enzyme able to conjugate NADpH thioredoxin reductase （NTR） and thioredoxin （TRX） activities for the efficient reduction of 2-Cys peroxiredoxin （2-Cys pRX）. Because NADpH can be produced in chloroplasts during darkness, NTRC plays a key role for plant peroxide detoxification during the night. Here, it is shown that the quaternary structure of NTRC is highly dependent on its redox status. In vitro, most of the enzyme adopted an oligomeric state that disaggregated in dimers upon addition of NADpH, NADH, or DTT. Gel filtration and Western blot analysis of protein extracts from Arabidopsis chloroplast stroma showed that native NTRC forms aggregates, which are sensitive to NADpH and DTT, suggesting that the aggregation state might be a significant aspect of NTRC activity in vivo. Moreover, the enzyme is localized in clusters in Arabidopsis chloroplasts. NTRC triple and double mutants, A164G- V182E-R183F and A164G-R183F, replacing key residues of NADpH binding site, showed reduced activity but were still able to dimerize though with an increase in intermediary forms. Based on these results, we propose that the catalytically active form of NTRC is the dimer, which formation is induced by NADpH.

关键词： Abiotic/environmental stress oxidative and photo-oxidative stress photosynthesis Arabidopsis rice.

Sequence-activated chemiluminescence probes: programmable illumination for high-contrast in vivo sensing and imaging

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Science China Chemistry 2025年第1期68卷 26-34页

作者： Yutao Zhang juan Li Wei-Hong Zhu Zhiqian Guo Shanghai Key Laboratory of Functional Materials Chemistry Joint International Research Laboratory of Precision Chemistry and Molecular Engineering Institute of Fine Chemicals School of Chemistry and Molecular Engineering East China University of Science and Technology State Key Laboratory of Bioreactor Engineering Shanghai Frontier Science Research Base of Optogenetic Techniques for Cell MetabolismEast China University of Science & Technology

Sequence-activated chemiluminescence(CL) technique offers a unique approach to detecting specific biomolecules or cellular events with high sensitivity and spatial resolution. The fundamental principle behind sequence-activated CL probes involves tailoring highly-controllable CL signals in response to specific sequences or events of interest, thus enabling high-contrast signals under complex physiological conditions. This sequential activation could be triggered by enzymes, reactive oxygen species(ROS), biothiols or changes in the microenvironment. These unique sequence-activated CL probes bestow several advantages, including minimal background, deep-tissue penetration, and the ability of non-invasive or minimally invasive detection. The sequence-activated CL techniques represent a significant advancement in molecular imaging and diagnostics. In this mini-review, we focus on the latest developments in sequential CL probes, addressing the technical challenges and discussing the future trajectory by harnessing CL signaling and molecular recognition.

关键词： chemiluminescnece sequence-activation in-vivo bioimaging cyclic peroxide

Functional explanation of extreme hatching asynchrony: Male Manipulation Hypothesis

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Zoological Research 2022年第5期43卷 843-850页

作者： manuel Soler Francisco ruiz-Raya Lucia Sanchez-perez juan Diego Ibanez-Álamo juan JoseSoler Departamento de Zoologia Facultad de CienciasUniversidad de GranadaGranada E-18071Spain Unidad Asociada Coevolucion:Cucos Hospedadores y Bacterias SimbiontesUniversidad de GranadaGranada E-18071Spain Centro de Investigacion Mariña Universidade de VigoGrupo de Ecoloxia AnimalVigo 36310Spain Departamento de Ecologia Funcional y Evolutiva Estacion Experimental de ZonasÁridas(CSIC)Almeria E-4120Spain

Hatching asynchrony in birds is considered an adaptation to facilitate brood reduction because under conditions of food scarcity, the smallest nestling usually dies soon after hatching, thereby minimizing parental effort. However, in species with extreme hatching asynchrony, the last hatchlings paradoxically experience a very low probability of survival and death can take so long that it can hardly be considered an adaptation. Here, we propose and experimentally tested a new adaptive hypothesis explaining the brood reduction paradox, namely the“Male Manipulation Hypothesis”. Our hypothesis suggests that by inducing asynchronous hatching,females increase the feeding requirements of the brood, which will induce males to increase provisioning effort. In addition, females may extend the period of male manipulation by feeding the smallest nestling just enough to sustain life. Our study showed that male common blackbirds(Turdus merula) increased their effort(i.e., number of food items per hour) in experimental asynchronous broods compared to synchronous broods, while females reduced their contribution, as predicted by the hypothesis.

关键词： Brood reduction Food allocation Hatchingasynchrony Malemanipulation hypothesis Sexual differences in food allocation Turdus merula

Beacon-Less Geographic Routing in Real Wireless Sensor Networks

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Journal of Computer Science & Technology 2008年第3期23卷 438-450页

作者： juan A.Sánchez Rafael Marín-pérez pedro M.ruiz Department of Information and Communications Engineering University of MurciaSpain

Geographic Routing （GR） algorithms require nodes to periodically transmit HELLO messages to allow neighbors to know their positions （beaconing mechanism）. Beacon-less routing algorithms have recently been proposed to reduce the control overheads due to these messages. However, existing beacon-less algorithms have not considered realistic physical layers. Therefore, those algorithms cannot work properly in realistic scenarios. In this paper we present a new beacon-less routing protocol called BOSS. Its design is based on the conclusions of our open-field experiments using Tmote-sky sensors. BOSS is adapted to error-prone networks and incorporates a new mechanism to reduce collisions and duplicate messages produced during the selection of the next forwarder node. We compare BOSS with Beacon-Less Routing （BLR） and Contention-Based Forwarding （CBF） algorithms through extensive simulations. The results show that our scheme is able to *** almost perfect packet delivery ratio （like BLR） while having a low bandwidth consumption （even lower than CBF）. Additionally, we carried out an empirical evaluation in a real testbed that shows the correctness of our simulation results.

关键词： geographic routing beacon-less forwarding performance evaluation real deployment

2-Cys peroxiredoxins participate in the Oxidation of Chloroplast Enzymes in the Dark

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Molecular plant 2018年第11期11卷 1377-1388页

作者： Valle Ojeda juan manuel perez-ruiz Francisco Javier Cejudo Instituto de Bioquimica Vegetaly Fotosintesis Universidad de Sevilla and Consejo Superior de lnvestigaciones CientificasAvenida Americo Vespucio 4941092SevillaSpain

Most redox-regulated chloroplast enzymes are reduced during the day and oxidized during the *** the reduction mechanism of light-dependent enzymes is well known,the mechanism mediating their oxidation in the dark remains *** thiol-dependent peroxidases,2-Cys peroxiredoxins (prxs),play a key role in light-dependent reduction of chloroplast *** transfer reducing equivalents of thiols to hydrogen peroxide,suggesting the participation of these peroxidases in enzyme oxidation in the ***,we have addressed this issue by analyzing the redox state of well-known redox-regulated chloroplast enzymes in response to darkness in Arabidopsis thaliana mutants deficient in chloroplastlocalized prxs (2-Cys prxs A and B,prx ⅡE,and prx Q).Mutant plants lacking 2-Cys prxs A and B,and plants overexpressing NADpH-dependent thioredoxin (Trx) reductase C showed delayed oxidation of chloroplast enzymes in the *** contrast,the deficiencies of prx ⅡE or prx Q exerted no *** vitro assays allowed the reconstitution of the pathway of reducing equivalents from reduced fructose 1,6-bisphosphatase to hydrogen peroxide mediated by Trxs and 2-Cys *** together,these results suggest that 2-Cys prxs participate in the short-term oxidation of chloroplast enzymes in the dark.

关键词： chloroplast enzyme oxidation peroxiredoxin thioredoxin hydrogen peroxide darkness

presynaptic endoplasmic reticulum architecture and hereditary spastic paraplegia

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Neural Regeneration Research 2024年第3期19卷 485-486页

作者： juan Josépérez-Moreno Instituto de Biomedicina de Sevilla(IBiS) Hospital Universitario Virgen Del Rocío/CSIC/Universidad de Sevillaand Departamento de Biología CelularFacultad de BiologíaUniversidad de SevillaSevilleSpain

Hereditary spastic paraplegia(HSp)is a clinically and genetically heterogeneous neurodegenerative disorder,characterized primarily by progressive spasticity and weakness in the lower *** ients can also experience peripheral neuropathy,cognitive impairment,and other neurological *** date,more than 80 genes have been implicated in HSp,encompassing various cellular components,although mutations in genes encoding endoplasmic reticulum(ER)-shaping proteins are the most prevalent(parodi et al.,2017).ER-shaping proteins are generally known for regulating the tubulation and curvation of the ER,but most of them show additional functions,including fusion of ER tubules,microtubule-severing,ER autophagy,lipid droplet synthesis,contact sites with other organelles(Öztürk et al.,2020).This highlights the complexity of studying the role of these proteins and the link between ER function and HSp.

关键词： reticulum endoplasmic

Rehabilitation of degraded areas in northeastern patagonia, Argentina: Effects of environmental conditions and plant functional traits on performance of native woody species

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Journal of Arid Land 2020年第4期12卷 653-665页

作者： juan M ZEBERIO Carolina A pÉrez National University of Río Negro Atlantic HeadquartersCenter for Environmental Studies from Norpatagonia(CEANPa)Viedma 8500Argentina National Council of Scientific and Technical Research(CONICET) Viedma 8500Argentina Ecological and Environmental Systems Research Laboratory(LISEA) National University of La PlataLa Plata 1900Argentina

Degradation processes affect a vast area of arid and semi-arid lands around the world and damage the environment and people′s health. Degradation processes are driven by human productive activities that cause direct and indirect effects on natural resources, such as species extinction at regional scale, reduction and elimination of vegetation cover, soil erosion, etc. In this context, ecological rehabilitation is an important tool to recover key aspects of the degraded ecosystem. Rehabilitation trials rely on the use of native plant species with characteristics that allow them to obtain high survival and growth rates. The aim of this work was to assess the survival and growth of native woody species in degraded areas of northeastern patagonia and relate them to plant functional traits and environmental variables. We observed high early and late survival rates, and growth rates in prosopis flexuosa DC. var. depressa F.A. Roig and Schinus johnstonii F.A. Barkley, and low values in Condalia microphylla Cav. and Geoffroea decorticans(Gillies ex Hook. & Arn.) Burkart. Early survival rates were positively associated with specific leaf area(SLA) and precipitation, but negatively associated with wood density, the maximum mean temperature of the warmest month and the minimum mean temperature of the coldest month. Late survival rates were positively associated with SLA and soil organic matter, but negatively associated with plant height and precipitation. The temperature had a positive effect on late survival rates once the plants overcame the critical period of the first summer after they were transplanted to the field. prosopis flexuosa and S. johnstonii were the most successful species in our study. This could be due to their functional traits that allow these species to acclimatize to the local environment. Further research should focus on C. microphylla and G. decorticans to determine how they relate to productive conditions, acclimation to environmental stress, auto-eco

关键词： arid lands Condalia microphylla Geoffroea decorticans prosopis flexuosa Schinus johnstonii survival rates height growth basal diameter growth

Stiffness-tunable biomaterials provide a good extracellular matrix environment for axon growth and regeneration

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Neural Regeneration Research 2025年第5期20卷 1364-1376页

作者： Ronglin Han Lanxin Luo Caiyan Wei Yaru Qiao Jiming Xie Xianchao pan juan Xing Department of pathophysiology School of Basic Medical SciencesSouthwest Medical UniversityLuzhouSichuan ProvinceChina Department of Medicinal Chemistry School of PharmacySouthwest Medical UniversityLuzhouSichuan ProvinceChina

Neuronal growth, extension, branching, and formation of neural networks are markedly influenced by the extracellular matrix—a complex network composed of proteins and carbohydrates secreted by cells. In addition to providing physical support for cells, the extracellular matrix also conveys critical mechanical stiffness cues. During the development of the nervous system, extracellular matrix stiffness plays a central role in guiding neuronal growth, particularly in the context of axonal extension, which is crucial for the formation of neural networks. In neural tissue engineering, manipulation of biomaterial stiffness is a promising strategy to provide a permissive environment for the repair and regeneration of injured nervous tissue. Recent research has fine-tuned synthetic biomaterials to fabricate scaffolds that closely replicate the stiffness profiles observed in the nervous system. In this review, we highlight the molecular mechanisms by which extracellular matrix stiffness regulates axonal growth and regeneration. We highlight the progress made in the development of stiffness-tunable biomaterials to emulate in vivo extracellular matrix environments, with an emphasis on their application in neural repair and regeneration, along with a discussion of the current limitations and future prospects. The exploration and optimization of the stiffness-tunable biomaterials has the potential to markedly advance the development of neural tissue engineering.

关键词： alginate axon growth biomaterials extracellular matrix neural repair neurons neuroregeneration polyacrylamide polydimethylsiloxane stiffness

Anti-amyloid antibodies in Alzheimer’s disease: what did clinical trials teach us?

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Neural Regeneration Research 2025年第4期20卷 1092-1093页

作者： Danko Jeremic Lydia Jiménez-Díaz juan D.Navarro-López Neurophysiology&Behavior Lab University of Castilla-La ManchaBiomedical Research Center(CRIB)School of Medicine of Ciudad RealCiudad RealSpain

Although many causes of Alzheimer’s disease(AD)may exist,both the original amyloid cascade and tau hypotheses posit that abnormal misfolding and accumulation of amyloid-β(Aβ)and tau protein is the central event causing the ***,that conclusion could be only partly true,and there is conflicting evidence about the role of both proteins in AD,being able to precede and influence one *** researchers argue that these proteins are mere executors rather than primary causes of ***,there have been continuing refinements of both hypotheses,with alternative explanations proposed.Aβand tau proteins may be independently involved in specific neurotoxic pathways;yet there may be other crucial processes going on in early ***,accumulating evidence suggests that Aβand tau act synergistically,rather than additively in disease onset(Jeremic et al.,2021,2023a).

关键词： amyloid Alzheimer additive