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Svietlova N, Zhyr L, Reichelt M, Grabe V, Mithöfer A. Glutamine as sole nitrogen source prevents induction of nitrate transporter gene NRT2.4 and affects amino acid metabolism in Arabidopsis. Front Plant Sci 2024; 15:1369543. [PMID: 38633457 PMCID: PMC11022244 DOI: 10.3389/fpls.2024.1369543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Accepted: 03/14/2024] [Indexed: 04/19/2024]
Abstract
Plants assimilate inorganic nitrogen (N) to glutamine. Glutamine is the most abundant amino acid in most plant species, the N-supplying precursor of all N-containing compounds in the cell and the first organic nitrogen molecule formed from inorganic nitrogen taken up by the roots. In addition to its role in plant nutrition, glutamine most likely also has a function as a signaling molecule in the regulation of nitrogen metabolism. We investigated whether glutamine influences the high-affinity transporter system for nitrate uptake. Therefore, we analyzed the expression of the nitrate transporter NRT2.4, which is inducible by N deficiency, in Arabidopsis thaliana grown under different nitrogen starvation scenarios, comparing nitrate or glutamine as the sole nitrogen source. Using the reporter line ProNRT2.4:GFP and two independent knockout lines, nrt2.4-1 and nrt2.4-2, we analyzed gene expression and amino acid profiles. We showed that the regulation of NRT2.4 expression depends on available nitrogen in general, for example on glutamine as a nitrogen source, and not specifically on nitrate. In contrast to high nitrate concentrations, amino acid profiles changed to an accumulation of amino acids containing more than one nitrogen during growth in high glutamine concentrations, indicating a switch to nitrogen storage metabolism. Furthermore, we demonstrated that the nrt2.4-2 line shows unexpected effects on NRT2.5 gene expression and the amino acids profile in shoots under high glutamine supply conditions compared to Arabidopsis wild type and nrt2.4-1, suggesting non-NRT2.4-related metabolic consequences in this knockout line.
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Affiliation(s)
- Nataliia Svietlova
- Research Group Plant Defense Physiology, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Liza Zhyr
- Research Group Plant Defense Physiology, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Michael Reichelt
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Veit Grabe
- Microscopic Imaging Service Group, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Axel Mithöfer
- Research Group Plant Defense Physiology, Max Planck Institute for Chemical Ecology, Jena, Germany
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Wang X, Wu C, Wang Z, Liu W. When do tripdoublet states fluoresce? A theoretical study of copper(II) porphyrin. Front Chem 2023; 11:1259016. [PMID: 38025061 PMCID: PMC10667454 DOI: 10.3389/fchem.2023.1259016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 10/23/2023] [Indexed: 12/01/2023] Open
Abstract
Open-shell molecules rarely fluoresce, due to their typically faster non-radiative relaxation rates compared to closed-shell ones. Even rarer is the fluorescence from states that have two more unpaired electrons than the open-shell ground state, since they involve excitations from closed-shell orbitals to vacant-shell orbitals, which are typically higher in energy compared to excitations from or out of open-shell orbitals. States that are dominated by the former type of excitations are known as tripdoublet states when they can be described as a triplet excitation antiferromagnetically coupled to a doublet state, and their description by unrestricted single-reference methods (e.g., U-TDDFT) is notoriously inaccurate due to large spin contamination. In this work, we applied our spin-adapted TDDFT method, X-TDDFT, and the efficient and accurate static-dynamic-static second order perturbation theory (SDSPT2), to the study of the excited states as well as their relaxation pathways of copper(II) porphyrin; previous experimental works suggested that the photoluminescence of some substituted copper(II) porphyrins originate from a tripdoublet state, formed by a triplet ligand π → π* excitation antiferromagnetically coupled with the unpaired d electron. Our results demonstrated favorable agreement between the X-TDDFT, SDSPT2 and experimental excitation energies, and revealed noticeable improvements of X-TDDFT compared to U-TDDFT, not only for vertical excitation energies but also for adiabatic energy differences. These suggest that X-TDDFT is a reliable tool for the study of tripdoublet state fluorescence. Intriguingly, we showed that the aforementioned tripdoublet state is only slightly above the lowest doublet excited state and lies only slightly higher than the lowest quartet state, which suggests that the tripdoublet of copper(II) porphyrin is long-lived enough to fluoresce due to a lack of efficient non-radiative relaxation pathways; an explanation for this unusual state ordering is given. Indeed, thermal vibration correlation function (TVCF)-based calculations of internal conversion, intersystem crossing, and radiative transition rates confirm that copper(II) porphyrin emits thermally activated delayed fluorescence (TADF) and a small amount of phosphorescence at low temperature (83 K), in accordance with experiment. The present contribution is concluded by a few possible approaches of designing new molecules that fluoresce from tripdoublet states.
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Affiliation(s)
- Xingwen Wang
- Qingdao Institute for Theoretical and Computational Sciences, Shandong University, Qingdao, China
| | - Chenyu Wu
- Qingdao Institute for Theoretical and Computational Sciences, Shandong University, Qingdao, China
| | - Zikuan Wang
- Qingdao Institute for Theoretical and Computational Sciences, Shandong University, Qingdao, China
- Max-Planck-Institut für Kohlenforschung, Mülheim an der Ruhr, Germany
| | - Wenjian Liu
- Qingdao Institute for Theoretical and Computational Sciences, Shandong University, Qingdao, China
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Zhang X, Penkov S, Kurzchalia TV, Zaburdaev V. Periodic ethanol supply as a path toward unlimited lifespan of Caenorhabditis elegans dauer larvae. Front Aging 2023; 4:1031161. [PMID: 37731965 PMCID: PMC10507685 DOI: 10.3389/fragi.2023.1031161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 08/14/2023] [Indexed: 09/22/2023]
Abstract
The dauer larva is a specialized stage of worm development optimized for survival under harsh conditions that have been used as a model for stress resistance, metabolic adaptations, and longevity. Recent findings suggest that the dauer larva of Caenorhabditis elegans may utilize external ethanol as an energy source to extend their lifespan. It was shown that while ethanol may serve as an effectively infinite source of energy, some toxic compounds accumulating as byproducts of its metabolism may lead to the damage of mitochondria and thus limit the lifespan of larvae. A minimal mathematical model was proposed to explain the connection between the lifespan of a dauer larva and its ethanol metabolism. To explore theoretically if it is possible to extend even further the lifespan of dauer larvae, we incorporated two natural mechanisms describing the recovery of damaged mitochondria and elimination of toxic compounds, which were previously omitted in the model. Numerical simulations of the revised model suggested that while the ethanol concentration is constant, the lifespan still stays limited. However, if ethanol is supplied periodically, with a suitable frequency and amplitude, the dauer could survive as long as we observe the system. Analytical methods further help to explain how feeding frequency and amplitude affect lifespan extension. Based on the comparison of the model with experimental data for fixed ethanol concentration, we proposed the range of feeding protocols that could lead to even longer dauer survival and it can be tested experimentally.
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Affiliation(s)
- Xingyu Zhang
- Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
- Max-Planck-Zentrum für Physik und Medizin, Erlangen, Germany
| | - Sider Penkov
- Center of Membrane Biochemistry and Lipid Research, University Clinic and Faculty of Medicine, Dresden, Germany
- Institute for Clinical Chemistry and Laboratory Medicine, University Clinic and Faculty of Medicine, Dresden, Germany
| | | | - Vasily Zaburdaev
- Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
- Max-Planck-Zentrum für Physik und Medizin, Erlangen, Germany
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Herget U, Ryu S, De Marco RJ. Altered glucocorticoid reactivity and behavioral phenotype in rx3-/- larval zebrafish. Front Endocrinol (Lausanne) 2023; 14:1187327. [PMID: 37484970 PMCID: PMC10358986 DOI: 10.3389/fendo.2023.1187327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 06/21/2023] [Indexed: 07/25/2023] Open
Abstract
Introduction The transcription factor rx3 is important for the formation of the pituitary and parts of the hypothalamus. Mutant animals lacking rx3 function have been well characterized in developmental studies, but relatively little is known about their behavioral phenotypes. Methods We used cell type staining to reveal differences in stress axis architecture, and performed cortisol measurements and behavior analysis to study both hormonal and behavioral stress responses in rx3 mutants. Results and Discussion Consistent with the role of rx3 in hypothalamus and pituitary development, we show a distinct loss of corticotrope cells involved in stress regulation, severe reduction of pituitary innervation by hypothalamic cells, and lack of stress-induced cortisol release in rx3 mutants. Interestingly, despite these deficits, we report that rx3-/- larval zebrafish can still display nominal behavioral responses to both stressful and non-stressful stimuli. However, unlike wildtypes, mutants lacking proper pituitary-interrenal function do not show enhanced behavioral performance under moderate stress level, supporting the view that corticotroph cells are not required for behavioral responses to some types of stressful stimuli but modulate subtle behavioral adjustments under moderate stress.
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Affiliation(s)
- Ulrich Herget
- Research Group Developmental Genetics of the Nervous System, Max Planck Institute for Medical Research, Heidelberg, Germany
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, United States
| | - Soojin Ryu
- Research Group Developmental Genetics of the Nervous System, Max Planck Institute for Medical Research, Heidelberg, Germany
- Living Systems Institute, College of Medicine and Health, University of Exeter, Exeter, United Kingdom
| | - Rodrigo J. De Marco
- Research Group Developmental Genetics of the Nervous System, Max Planck Institute for Medical Research, Heidelberg, Germany
- School of Biological and Environmental Sciences, Faculty of Science, Liverpool John Moores University, Liverpool, United Kingdom
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Schott S, Scheuer R, Ermoli F, Glatter T, Evguenieva-Hackenberg E, Diepold A. A ParDE toxin-antitoxin system is responsible for the maintenance of the Yersinia virulence plasmid but not for type III secretion-associated growth inhibition. Front Cell Infect Microbiol 2023; 13:1166077. [PMID: 37228670 PMCID: PMC10203498 DOI: 10.3389/fcimb.2023.1166077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 04/20/2023] [Indexed: 05/27/2023] Open
Abstract
Many Gram-negative pathogens utilize the type III secretion system (T3SS) to translocate virulence-promoting effector proteins into eukaryotic host cells. The activity of this system results in a severe reduction of bacterial growth and division, summarized as secretion-associated growth inhibition (SAGI). In Yersinia enterocolitica, the T3SS and related proteins are encoded on a virulence plasmid. We identified a ParDE-like toxin-antitoxin system on this virulence plasmid in genetic proximity to yopE, encoding a T3SS effector. Effectors are strongly upregulated upon activation of the T3SS, indicating a potential role of the ParDE system in the SAGI or maintenance of the virulence plasmid. Expression of the toxin ParE in trans resulted in reduced growth and elongated bacteria, highly reminiscent of the SAGI. Nevertheless, the activity of ParDE is not causal for the SAGI. T3SS activation did not influence ParDE activity; conversely, ParDE had no impact on T3SS assembly or activity itself. However, we found that ParDE ensures the presence of the T3SS across bacterial populations by reducing the loss of the virulence plasmid, especially under conditions relevant to infection. Despite this effect, a subset of bacteria lost the virulence plasmid and regained the ability to divide under secreting conditions, facilitating the possible emergence of T3SS-negative bacteria in late acute and persistent infections.
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Affiliation(s)
- Saskia Schott
- Department of Ecophysiology, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Robina Scheuer
- Department of Microbiology and Molecular Biology, Justus Liebig University Gießen, Gießen, Germany
| | - Francesca Ermoli
- Department of Ecophysiology, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Timo Glatter
- Core Facility for Mass spectrometry & Proteomics, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | | | - Andreas Diepold
- Department of Ecophysiology, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
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Biswas T, Yuvaraj JK, Hansson BS, Löfstedt C, Anderbrant O, Andersson MN. Characterization of olfactory sensory neurons in the striped ambrosia beetle Trypodendron lineatum. Front Physiol 2023; 14:1155129. [PMID: 37020460 PMCID: PMC10067612 DOI: 10.3389/fphys.2023.1155129] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 03/10/2023] [Indexed: 04/07/2023] Open
Abstract
Introduction: The striped ambrosia beetle Trypodendron lineatum (Coleoptera, Curculionidae, Scolytinae) is a major forest pest in the Holarctic region. It uses an aggregation pheromone and host and non-host volatiles to locate suitable host trees, primarily stressed or dying conifer trees. The beetles bore into the xylem and inoculate spores of their obligate fungal mutualist Phialophoropsis ferruginea inside their excavated egg galleries, with the fungus serving as the main food source for the developing larvae. Olfactory sensory neuron (OSN) responses to pheromones and host volatiles are poorly understood in T. lineatum and other ambrosia beetles, and nothing is known about potential responses to fungal volatiles. Methods: We screened responses of OSNs present in 170 antennal olfactory sensilla using single sensillum recordings (SSR) and 57 odor stimuli, including pheromones, host and non-host compounds, as well as volatiles produced by P. ferruginea and fungal symbionts of other scolytine beetles. Results and Discussion: Thirteen OSN classes were characterized based on their characteristic response profiles. An OSN class responding to the aggregation pheromone lineatin was clearly the most abundant on the antennae. In addition, four OSN classes responded specifically to volatile compounds originating from the obligate fungal mutualist and three responded to non-host plant volatiles. Our data also show that T. lineatum has OSN classes tuned to pheromones of other bark beetles. Several OSN classes showed similar response profiles to those previously described in the sympatric bark beetle Ips typographus, which may reflect their shared ancestry.
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Affiliation(s)
- Twinkle Biswas
- Department of Biology, Lund University, Lund, Sweden
- *Correspondence: Twinkle Biswas,
| | | | - Bill S. Hansson
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Jena, Germany
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Levario-Diaz V, Alvarado RE, Rodriguez-Quinteros CM, Fink A, Christian J, Feng W, Cavalcanti-Adam EA. 1D micro-nanopatterned integrin ligand surfaces for directed cell movement. Front Cell Dev Biol 2022; 10:972624. [PMID: 36531964 PMCID: PMC9755580 DOI: 10.3389/fcell.2022.972624] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2022] [Accepted: 11/21/2022] [Indexed: 12/23/2023] Open
Abstract
Cell-extracellular matrix (ECM) adhesion mediated by integrins is a highly regulated process involved in many vital cellular functions such as motility, proliferation and survival. However, the influence of lateral integrin clustering in the coordination of cell front and rear dynamics during cell migration remains unresolved. For this purpose, we describe a novel protocol to fabricate 1D micro-nanopatterned stripes by integrating the block copolymer micelle nanolithography (BCMNL) technique and maskless near UV lithography-based photopatterning. The photopatterned 10 μm-wide stripes consist of a quasi-perfect hexagonal arrangement of gold nanoparticles, decorated with the RGD (arginine-glycine-aspartate) motif for single integrin heterodimer binding, and placed at a distance of 50, 80, and 100 nm to regulate integrin clustering and focal adhesion dynamics. By employing time-lapse microscopy and immunostaining, we show that the displacement and speed of fibroblasts changes according to the nanoscale spacing of adhesion sites. We found that as the lateral spacing of adhesive peptides increased, fibroblast morphology was more elongated. This was accompanied by a decreased formation of mature focal adhesions and stress fibers, which increased cell displacement and speed. These results provide new insights into the migratory behavior of fibroblasts in 1D environments and our protocol offers a new platform to design and manufacture confined environments in 1D for integrin-mediated cell adhesion.
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Affiliation(s)
- Victoria Levario-Diaz
- Department of Cellular Biophysics, Max Planck Institute for Medical Research, Heidelberg, Germany
| | | | | | - Andreas Fink
- Department of Cellular Biophysics, Max Planck Institute for Medical Research, Heidelberg, Germany
| | - Joel Christian
- Department of Cellular Biophysics, Max Planck Institute for Medical Research, Heidelberg, Germany
| | - Wenqian Feng
- Department of Cellular Biophysics, Max Planck Institute for Medical Research, Heidelberg, Germany
- College of Polymer Science and Engineering, Sichuan University, Chengdu, China
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Kraemer Y, Ghiazza C, Ragan AN, Ni S, Lutz S, Neumann EK, Fettinger JC, Nöthling N, Goddard R, Cornella J, Pitts CR. Strain-Release Pentafluorosulfanylation and Tetrafluoro(aryl)sulfanylation of [1.1.1]Propellane: Reactivity and Structural Insight. Angew Chem Int Ed Engl 2022; 61:e202211892. [PMID: 36137228 PMCID: PMC9828730 DOI: 10.1002/anie.202211892] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Indexed: 01/12/2023]
Abstract
We leveraged the recent increase in synthetic accessibility of SF5 Cl and Ar-SF4 Cl compounds to combine chemistry of the SF5 and SF4 Ar groups with strain-release functionalization. By effectively adding SF5 and SF4 Ar radicals across [1.1.1]propellane, we accessed structurally unique bicyclopentanes, bearing two distinct elements of bioisosterism. Upon evaluating these "hybrid isostere" motifs in the solid state, we measured exceptionally short transannular distances; in one case, the distance rivals the shortest nonbonding C⋅⋅⋅C contact reported to date. This prompted SC-XRD and DFT analyses that support the notion that a donor-acceptor interaction involving the "wing" C-C bonds is playing an important role in stabilization. Thus, these heretofore unknown structures expand the palette for highly coveted three-dimensional fluorinated building blocks and provide insight to a more general effect observed in bicyclopentanes.
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Affiliation(s)
- Yannick Kraemer
- Department of ChemistryUniversity of California, Davis1 Shields AvenueDavisCA 95616USA
| | - Clément Ghiazza
- Max-Planck-Institut für KohlenforschungKaiser-Wilhelm-Platz 145470Mülheim an der RuhrGermany
| | - Abbey N. Ragan
- Department of ChemistryUniversity of California, Davis1 Shields AvenueDavisCA 95616USA
| | - Shengyang Ni
- Max-Planck-Institut für KohlenforschungKaiser-Wilhelm-Platz 145470Mülheim an der RuhrGermany
| | - Sigrid Lutz
- Max-Planck-Institut für KohlenforschungKaiser-Wilhelm-Platz 145470Mülheim an der RuhrGermany
| | - Elizabeth K. Neumann
- Department of ChemistryUniversity of California, Davis1 Shields AvenueDavisCA 95616USA
| | - James C. Fettinger
- Department of ChemistryUniversity of California, Davis1 Shields AvenueDavisCA 95616USA
| | - Nils Nöthling
- Max-Planck-Institut für KohlenforschungKaiser-Wilhelm-Platz 145470Mülheim an der RuhrGermany
| | - Richard Goddard
- Max-Planck-Institut für KohlenforschungKaiser-Wilhelm-Platz 145470Mülheim an der RuhrGermany
| | - Josep Cornella
- Max-Planck-Institut für KohlenforschungKaiser-Wilhelm-Platz 145470Mülheim an der RuhrGermany
| | - Cody Ross Pitts
- Department of ChemistryUniversity of California, Davis1 Shields AvenueDavisCA 95616USA
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Kaim V, Joshi M, Stein M, Kaur-Ghumaan S. Mononuclear manganese complexes as hydrogen evolving catalysts. Front Chem 2022; 10:993085. [PMID: 36277350 PMCID: PMC9585328 DOI: 10.3389/fchem.2022.993085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 08/05/2022] [Indexed: 12/04/2022] Open
Abstract
Molecular hydrogen (H2) is one of the pillars of future non-fossil energy supply. In the quest for alternative, non-precious metal catalysts for hydrogen generation to replace platinum, biological systems such as the enzyme hydrogenase serve as a blueprint. By taking inspiration from the bio-system, mostly nickel- or iron-based catalysts were explored so far. Manganese is a known oxygen-reducing catalyst but has received much less attention for its ability to reduce protons in acidic media. Here, the synthesis, characterization, and reaction mechanisms of a series of four mono-nuclear Mn(I) complexes in terms of their catalytic performance are reported. The effect of the variation of equatorial and axial ligands in their first and second coordination spheres was assessed pertaining to their control of the turnover frequencies and overpotentials. All four complexes show reactivity and reduce protons in acidic media to release molecular hydrogen H2. Quantum chemical studies were able to assign and interpret spectral characterizations from UV–Vis and electrochemistry and rationalize the reaction mechanism. Two feasible reaction mechanisms of electrochemical (E) and protonation (C) steps were compared. Quantum chemical studies can assign peaks in the cyclic voltammetry to structural changes of the complex during the reaction. The first one-electron reduction is essential to generate an open ligand-based site for protonation. The distorted octahedral Mn complexes possess an inverted second one-electron redox potential which is a pre-requisite for a swift and facile release of molecular hydrogen. This series on manganese catalysts extends the range of elements of the periodic table which are able to catalyze the hydrogen evolution reaction and will be explored further.
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Affiliation(s)
- Vishakha Kaim
- Department of Chemistry, University of Delhi, Delhi,India
| | - Meenakshi Joshi
- Max-Planck-Institute for Dynamics of Complex Technical Systems, Molecular Simulations and Design Group, Magdeburg, Germany
| | - Matthias Stein
- Max-Planck-Institute for Dynamics of Complex Technical Systems, Molecular Simulations and Design Group, Magdeburg, Germany
- *Correspondence: Matthias Stein, ; Sandeep Kaur-Ghumaan,
| | - Sandeep Kaur-Ghumaan
- Department of Chemistry, University of Delhi, Delhi,India
- *Correspondence: Matthias Stein, ; Sandeep Kaur-Ghumaan,
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Abstract
The nine membrane-delimited eukaryotic adenylyl cyclases are pseudoheterodimers with an identical domain order of seven (nine) distinct subdomains. Bioinformatics show that the protein evolved from a monomeric bacterial progenitor by gene duplication and fusion probably in a primordial eukaryotic cell around 1.5 billion years ago. Over a timespan of about 1 billion years, the first fusion product diverged into nine highly distinct pseudoheterodimeric isoforms. The evolutionary diversification ended approximately 0.5 billion years ago because the present isoforms are found in the living fossil coelacanth, a fish. Except for the two catalytic domains, C1 and C2, the mAC isoforms are fully diverged. Yet, within each isoform a high extent of conservation of respective subdomains is found. This applies to the C- and N-termini, a long linker region between the protein halves (C1b), two short cyclase-transducing-elements (CTE) and notably to the two hexahelical membrane domains TM1 and TM2. Except for the membrane anchor all subdomains were previously implicated in regulatory modalities. The bioinformatic results unequivocally indicate that the membrane anchors must possess an important regulatory function specifically tailored for each mAC isoform.
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Renahan T, Sommer RJ. Multidimensional competition of nematodes affects plastic traits in a beetle ecosystem. Front Cell Dev Biol 2022; 10:985831. [PMID: 36092706 PMCID: PMC9449363 DOI: 10.3389/fcell.2022.985831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 08/01/2022] [Indexed: 12/03/2022] Open
Abstract
Resource competition has driven the evolution of novel polyphenisms in numerous organisms, enhancing fitness in constantly changing environmental conditions. In natural communities, the myriad interactions among diverse species are difficult to disentangle, but the multidimensional microscopic environment of a decaying insect teeming with bacteria and fighting nematodes provides pliable systems to investigate. Necromenic nematodes of the family Diplogastridae live on beetles worldwide, innocuously waiting for their hosts’ deaths to feast on the blooming bacteria. Often, more than one worm species either affiliates with the insect or joins the microbial meal; thus, competition over limited food ensues, and phenotypic plasticity provides perks for species capable of employing polyphenisms. The recently established system of cockchafer Gymnogaster bupthalma and its occasional co-infestation of Pristionchus mayeri and Acrostichus spp. has revealed that these worms will simultaneously utilize two polyphenisms to thrive in a competitive environment. While both genera maintain plastic capacities in mouth form (strictly bacterial-feeding and omnivorous predation) and developmental pathway (direct and arrested development, dauer), P. mayeri employs both when faced with competition from Acrostichus. Here, we took advantage of the malleable system and added a third competitor, model nematode Pristionchus pacificus. Intriguingly, with a third competitor, P. mayeri is quicker to exit dauer and devour available food, while Acrostichus hides in dauer, waiting for the two Pristionchus species to leave the immediate environment before resuming development. Thus, experimental manipulation of short-lived ecosystems can be used to study the roles of polyphenisms in organismal interactions and their potential significance for evolution.
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Mihlan M, Glaser KM, Epple MW, Lämmermann T. Neutrophils: Amoeboid Migration and Swarming Dynamics in Tissues. Front Cell Dev Biol 2022; 10:871789. [PMID: 35478973 PMCID: PMC9038224 DOI: 10.3389/fcell.2022.871789] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Accepted: 03/03/2022] [Indexed: 01/02/2023] Open
Abstract
Neutrophils are key cells of our innate immune response with essential roles for eliminating bacteria and fungi from tissues. They are also the prototype of an amoeboid migrating leukocyte. As one of the first blood-recruited immune cell types during inflammation and infection, these cells can invade almost any tissue compartment. Once in the tissue, neutrophils undergo rapid shape changes and migrate at speeds higher than most other immune cells. They move in a substrate-independent manner in interstitial spaces and do not follow predetermined tissue paths. Instead, neutrophil navigation is largely shaped by the chemokine and chemoattractant milieu around them. This highlights the decisive role of attractant-sensing G-protein coupled receptors (GPCRs) and downstream molecular pathways for controlling amoeboid neutrophil movement in tissues. A diverse repertoire of cell-surface expressed GPCRs makes neutrophils the perfect sentinel cell type to sense and detect danger-associated signals released from wounds, inflamed interstitium, dying cells, complement factors or directly from tissue-invading microbes. Moreover, neutrophils release attractants themselves, which allows communication and coordination between individual cells of a neutrophil population. GPCR-mediated positive feedback mechanisms were shown to underlie neutrophil swarming, a population response that amplifies the recruitment of amoeboid migrating neutrophils to sites of tissue injury and infection. Here we discuss recent findings and current concepts that counteract excessive neutrophil accumulation and swarm formation. In particular, we will focus on negative feedback control mechanisms that terminate neutrophil swarming to maintain the delicate balance between tissue surveillance, host protection and tissue destruction.
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Affiliation(s)
- Michael Mihlan
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
| | - Katharina M. Glaser
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
- International Max Planck Research School for Immunobiology, Epigenetics and Metabolism (IMPRS-IEM), Freiburg, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Maximilian W. Epple
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
- International Max Planck Research School for Immunobiology, Epigenetics and Metabolism (IMPRS-IEM), Freiburg, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Tim Lämmermann
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
- *Correspondence: Tim Lämmermann,
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13
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Endo T, Ziems KM, Richter M, Fröbel FG, Hishikawa A, Gräfe S, Légaré F, Ibrahim H. Post-Ionization Dynamics of the Polar Molecule OCS in Asymmetric Laser Fields. Front Chem 2022; 10:859750. [PMID: 35464205 PMCID: PMC9023801 DOI: 10.3389/fchem.2022.859750] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 03/07/2022] [Indexed: 11/20/2022] Open
Abstract
We have investigated the dissociation mechanisms of the prototypical heavy polar molecule OCS into the two break-up channels of the dication, OCS2+ → O+ + CS+ and OC+ + S+, in phase-locked two-color intense laser fields. The branching ratio of the breaking of the C–O and C–S bonds followed a pronounced 2π-oscillation with a modulation depth of 11%, depending on the relative phase of the two-color laser fields. The fragment ejection direction of both break-up channels reflects the anisotropy of the tunneling ionization rate, following a 2π-periodicity, as well. The two dissociation pathways in the C–S bond breaking channel show different phase dependencies of the fragment ejection direction, which are assigned to post-ionization dynamics. These observations, resulting from the excitation with asymmetric two-color intense laser fields, supported by state-of-the-art theoretical simulations, reveal the importance of post-ionization population dynamics in addition to tunneling ionization in the molecular fragmentation processes, even for heavy polar molecules.
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Affiliation(s)
- Tomoyuki Endo
- Institut national de la recherche scientifique, Centre Énergie Matériaux et Télécommunications, Varennes, QC, Canada
- Kansai Photon Science Institute, National Institutes for Quantum Science and Technology, Kizugawa, Japan
| | - Karl Michael Ziems
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich Schiller University Jena, Jena, Germany
- Max Planck School of Photonics, Jena, Germany
| | - Martin Richter
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich Schiller University Jena, Jena, Germany
| | - Friedrich G. Fröbel
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich Schiller University Jena, Jena, Germany
| | - Akiyoshi Hishikawa
- Department of Chemistry, Graduate School of Science, Nagoya University, Nagoya, Japan
- Research Center for Materials Science, Nagoya University, Nagoya, Japan
| | - Stefanie Gräfe
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich Schiller University Jena, Jena, Germany
- Max Planck School of Photonics, Jena, Germany
| | - François Légaré
- Institut national de la recherche scientifique, Centre Énergie Matériaux et Télécommunications, Varennes, QC, Canada
- *Correspondence: François Légaré, ; Heide Ibrahim,
| | - Heide Ibrahim
- Institut national de la recherche scientifique, Centre Énergie Matériaux et Télécommunications, Varennes, QC, Canada
- *Correspondence: François Légaré, ; Heide Ibrahim,
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14
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Cronan MR. In the Thick of It: Formation of the Tuberculous Granuloma and Its Effects on Host and Therapeutic Responses. Front Immunol 2022; 13:820134. [PMID: 35320930 PMCID: PMC8934850 DOI: 10.3389/fimmu.2022.820134] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 02/15/2022] [Indexed: 12/19/2022] Open
Abstract
The defining pathology of tuberculosis is the granuloma, an organized structure derived from host immune cells that surrounds infecting Mycobacterium tuberculosis. As the location of much of the bacteria in the infected host, the granuloma is a central point of interaction between the host and the infecting bacterium. This review describes the signals and cellular reprogramming that drive granuloma formation. Further, as a central point of host-bacterial interactions, the granuloma shapes disease outcome by altering host immune responses and bacterial susceptibility to antibiotic treatment, as discussed herein. This new understanding of granuloma biology and the signaling behind it highlights the potential for host-directed therapies targeting the granuloma to enhance antibiotic access and tuberculosis-specific immune responses.
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15
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Abstract
Sulfation is poorly understood in most invertebrates and a potential role of sulfation in the regulation of developmental and physiological processes of these organisms remains unclear. Also, animal model system approaches did not identify many sulfation-associated mechanisms, whereas phosphorylation and ubiquitination are regularly found in unbiased genetic and pharmacological studies. However, recent work in the two nematodes Caenorhabditis elegans and Pristionchus pacificus found a role of sulfatases and sulfotransferases in the regulation of development and phenotypic plasticity. Here, we summarize the current knowledge about the role of sulfation in nematodes and highlight future research opportunities made possible by the advanced experimental toolkit available in these organisms.
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Affiliation(s)
- Catia Igreja
- *Correspondence: Catia Igreja, ; Ralf J. Sommer,
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16
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Lewis CA, Kimmig ACS, Kroemer NB, Pooseh S, Smolka MN, Sacher J, Derntl B. No Differences in Value-Based Decision-Making Due to Use of Oral Contraceptives. Front Endocrinol (Lausanne) 2022; 13:817825. [PMID: 35528016 PMCID: PMC9075610 DOI: 10.3389/fendo.2022.817825] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Accepted: 03/11/2022] [Indexed: 12/17/2022] Open
Abstract
Fluctuating ovarian hormones have been shown to affect decision-making processes in women. While emerging evidence suggests effects of endogenous ovarian hormones such as estradiol and progesterone on value-based decision-making in women, the impact of exogenous synthetic hormones, as in most oral contraceptives, is not clear. In a between-subjects design, we assessed measures of value-based decision-making in three groups of women aged 18 to 29 years, during (1) active oral contraceptive intake (N = 22), (2) the early follicular phase of the natural menstrual cycle (N = 20), and (3) the periovulatory phase of the natural menstrual cycle (N = 20). Estradiol, progesterone, testosterone, and sex-hormone binding globulin levels were assessed in all groups via blood samples. We used a test battery which measured different facets of value-based decision-making: delay discounting, risk-aversion, risk-seeking, and loss aversion. While hormonal levels did show the expected patterns for the three groups, there were no differences in value-based decision-making parameters. Consequently, Bayes factors showed conclusive evidence in support of the null hypothesis. We conclude that women on oral contraceptives show no differences in value-based decision-making compared to the early follicular and periovulatory natural menstrual cycle phases.
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Affiliation(s)
- Carolin A. Lewis
- Department of Psychiatry and Psychotherapy, Tübingen Center for Mental Health (TüCMH), University of Tuebingen, Tuebingen, Germany
- Emotion Neuroimaging Lab, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
- International Max Planck Research School on Neuroscience of Communication: Function, Structure, and Plasticity, Leipzig, Germany
- *Correspondence: Carolin A. Lewis,
| | - Ann-Christin S. Kimmig
- Department of Psychiatry and Psychotherapy, Tübingen Center for Mental Health (TüCMH), University of Tuebingen, Tuebingen, Germany
- International Max Planck Research School for Cognitive and Systems Neuroscience, University of Tuebingen, Tuebingen, Germany
| | - Nils B. Kroemer
- Department of Psychiatry and Psychotherapy, Tübingen Center for Mental Health (TüCMH), University of Tuebingen, Tuebingen, Germany
| | - Shakoor Pooseh
- Department of Psychiatry, Technische Universität Dresden, Dresden, Germany
- Freiburg Center for Data Analysis and Modeling, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Michael N. Smolka
- Department of Psychiatry, Technische Universität Dresden, Dresden, Germany
| | - Julia Sacher
- Emotion Neuroimaging Lab, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
- Clinic for Cognitive Neurology, University of Leipzig, Leipzig, Germany
| | - Birgit Derntl
- Department of Psychiatry and Psychotherapy, Tübingen Center for Mental Health (TüCMH), University of Tuebingen, Tuebingen, Germany
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17
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Kaithal A, Chatterjee B, Werlé C, Leitner W. Acceptorless Dehydrogenation of Methanol to Carbon Monoxide and Hydrogen using Molecular Catalysts. Angew Chem Int Ed Engl 2021; 60:26500-26505. [PMID: 34596302 PMCID: PMC9299216 DOI: 10.1002/anie.202110910] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 09/23/2021] [Indexed: 12/16/2022]
Abstract
The acceptorless dehydrogenation of methanol to carbon monoxide and hydrogen was investigated using homogeneous molecular complexes. Complexes of ruthenium and manganese comprising the MACHO ligand framework showed promising activities for this reaction. The molecular ruthenium complex [RuH(CO)(BH4 )(HN(C2 H4 PPh2 )2 )] (Ru-MACHO-BH) achieved up to 3150 turnovers for carbon monoxide and 9230 turnovers for hydrogen formation at 150 °C reaching pressures up to 12 bar when the decomposition was carried out in a closed vessel. Control experiments affirmed that the metal complex mediates the initial fast dehydrogenation of methanol to formaldehyde and methyl formate followed by subsequent slow decarbonylation. Depending on the catalyst and reaction conditions, the CO/H2 ratio in the gas mixture thus varies over a broad range from almost pure hydrogen to the stoichiometric limit of 1:2.
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Affiliation(s)
- Akash Kaithal
- Max Planck Institute for Chemical Energy ConversionStiftstraße 34–3645470Mülheim a.d. RuhrGermany
| | - Basujit Chatterjee
- Max Planck Institute for Chemical Energy ConversionStiftstraße 34–3645470Mülheim a.d. RuhrGermany
| | - Christophe Werlé
- Max Planck Institute for Chemical Energy ConversionStiftstraße 34–3645470Mülheim a.d. RuhrGermany
- Ruhr University BochumUniversitätsstr. 15044801BochumGermany
| | - Walter Leitner
- Max Planck Institute for Chemical Energy ConversionStiftstraße 34–3645470Mülheim a.d. RuhrGermany
- Institut für Technische und Makromolekulare ChemieRWTH Aachen UniversityWorringer Weg 252074AachenGermany
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18
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Zhang S, Seeberger PH. Total Syntheses of Conjugation-Ready Repeating Units of Acinetobacter baumannii AB5075 for Glycoconjugate Vaccine Development. Chemistry 2021; 27:17444-17451. [PMID: 34665908 PMCID: PMC9298076 DOI: 10.1002/chem.202103234] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Indexed: 12/16/2022]
Abstract
Acinetobacter baumannii is an opportunistic pathogen that causes serious nosocomial infections. One of the multidrug-resistant strains, AB5075, can result in bacteremia, pneumonia and wound infections associated with high morbidity and mortality. The structurally unique glycans on the surface of these bacteria are attractive targets for the development of glycoconjugate vaccines. Here, we report the first total synthesis of the densely functionalized trisaccharide repeating unit of A. baumannii AB5075 as well as two analogues. The construction of 1,2-cis linkages between the rare sugars relies on a double-serial inversion strategy. The judicious selection of building blocks and reaction conditions allowed for stereoselective glycosylations, the installation of acetamido groups and the (S)-3-hydroxybutanoyl chain.
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Affiliation(s)
- Shuo Zhang
- Department of Biomolecular SystemsMax Planck Institute of Colloids and InterfacesAm Mühlenberg 114476PotsdamGermany
- Institute of Chemistry and BiochemistryFreie Universität BerlinArnimallee 2214195BerlinGermany
| | - Peter H. Seeberger
- Department of Biomolecular SystemsMax Planck Institute of Colloids and InterfacesAm Mühlenberg 114476PotsdamGermany
- Institute of Chemistry and BiochemistryFreie Universität BerlinArnimallee 2214195BerlinGermany
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19
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Oesinghaus L, Simmel FC. Controlling Gene Expression in Mammalian Cells Using Multiplexed Conditional Guide RNAs for Cas12a*. Angew Chem Int Ed Engl 2021; 60:23894-23902. [PMID: 34533878 PMCID: PMC8596743 DOI: 10.1002/anie.202107258] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 08/13/2021] [Indexed: 12/26/2022]
Abstract
Spatiotemporal control of the activity of CRISPR-associated (Cas) proteins is of considerable interest for basic research and therapeutics. Here, we show that conditional guide RNAs (gRNAs) for Cas12a can be transcribed in mammalian cells by RNA polymerase II, followed by activation via input-dependent processing of the 3' tail of the gRNA transcript. We demonstrate processing using an RNA strand displacement mechanism, as well as microRNA-dependent processing, and cleavage by a guanine-responsive ribozyme. We further demonstrate that Cas12a along with several independently switchable gRNAs can be compactly integrated on a single transcript using stabilizing RNA triplexes, providing a route towards Cas12a-based gene regulation constructs with multi-input switching capabilities. The principle is shown to work in HEK and mouse fibroblast cells using luminescence, fluorescence, and is also demonstrated for the conditional upregulation of an endogenous gene.
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Affiliation(s)
- Lukas Oesinghaus
- Physics Department, E14TU MunichAm Coulombwall 4a85748GarchingGermany
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20
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Markushyna Y, Schüßlbauer CM, Ullrich T, Guldi DM, Antonietti M, Savateev A. Chromoselective Synthesis of Sulfonyl Chlorides and Sulfonamides with Potassium Poly(heptazine imide) Photocatalyst. Angew Chem Int Ed Engl 2021; 60:20543-20550. [PMID: 34223699 PMCID: PMC8457082 DOI: 10.1002/anie.202106183] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 06/22/2021] [Indexed: 12/20/2022]
Abstract
Among external stimuli used to promote a chemical reaction, photocatalysis possesses a unique one-light. Photons are traceless reagents that provide an exclusive opportunity to alter chemoselectivity of the photocatalytic reaction varying the color of incident light. This strategy may be implemented by using a sensitizer capable to activate a specific reaction pathway depending on the excitation light. Herein, we use potassium poly(heptazine imide) (K-PHI), a type of carbon nitride, to generate selectively three different products from S-arylthioacetates simply varying the excitation light and otherwise identical conditions. Namely, arylchlorides are produced under UV/purple, sulfonyl chlorides with blue/white, and diaryldisulfides at green to red light. A combination of the negatively charged polyanion, highly positive potential of the valence band, presence of intraband states, ability to sensitize singlet oxygen, and multi-electron transfer is shown to enable this chromoselective conversion of thioacetates.
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Affiliation(s)
- Yevheniia Markushyna
- Department of Colloid ChemistryMax Planck Institute of Colloids and InterfacesAm Mühlenberg 114476PotsdamGermany
| | - Christoph M. Schüßlbauer
- Department of Chemistry and PharmacyInterdisciplinary Center for Molecular Materials(ICMM)Friedrich-Alexander University of Erlangen-NürnbergEgerlandstrasse 391058ErlangenGermany
| | - Tobias Ullrich
- Department of Chemistry and PharmacyInterdisciplinary Center for Molecular Materials(ICMM)Friedrich-Alexander University of Erlangen-NürnbergEgerlandstrasse 391058ErlangenGermany
| | - Dirk M. Guldi
- Department of Chemistry and PharmacyInterdisciplinary Center for Molecular Materials(ICMM)Friedrich-Alexander University of Erlangen-NürnbergEgerlandstrasse 391058ErlangenGermany
| | - Markus Antonietti
- Department of Colloid ChemistryMax Planck Institute of Colloids and InterfacesAm Mühlenberg 114476PotsdamGermany
| | - Aleksandr Savateev
- Department of Colloid ChemistryMax Planck Institute of Colloids and InterfacesAm Mühlenberg 114476PotsdamGermany
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21
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Abstract
The electronic and geometric structures of the water-oxidizing complex of photosystem II in the steps of the catalytic cycle that precede dioxygen evolution remain hotly debated. Recent structural and spectroscopic investigations support contradictory redox formulations for the active-site Mn4 CaOx cofactor in the final metastable S3 state. These range from the widely accepted MnIV 4 oxo-hydroxo model, which presumes that O-O bond formation occurs in the ultimate transient intermediate (S4 ) of the catalytic cycle, to a MnIII 2 MnIV 2 peroxo model representative of the contrasting "early-onset" O-O bond formation hypothesis. Density functional theory energetics of suggested S3 redox isomers are inconclusive because of extreme functional dependence. Here, we use the power of the domain-based local pair natural orbital approach to coupled cluster theory, DLPNO-CCSD(T), to present the first correlated wave function theory calculations of relative stabilities for distinct redox-isomeric forms of the S3 state. Our results enabled us to evaluate conflicting models for the S3 state of the oxygen-evolving complex (OEC) and to quantify the accuracy of lower-level theoretical approaches. Our assessment of the relevance of distinct redox-isomeric forms for the mechanism of biological water oxidation strongly disfavors the scenario of early-onset O-O formation advanced by literal interpretations of certain crystallographic models. This work serves as a case study in the application of modern coupled cluster implementations to redox isomerism problems in oligonuclear transition metal systems.
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Affiliation(s)
- Maria Drosou
- Inorganic Chemistry LaboratoryNational and Kapodistrian University of AthensPanepistimiopolisZografou15771Greece
| | - Dimitrios A. Pantazis
- Max-Planck-Institut für KohlenforschungKaiser-Wilhelm-Platz 145470Mülheim an derRuhrGermany
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22
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Fernandes SA, Demetriades C. The Multifaceted Role of Nutrient Sensing and mTORC1 Signaling in Physiology and Aging. Front Aging 2021; 2:707372. [PMID: 35822019 PMCID: PMC9261424 DOI: 10.3389/fragi.2021.707372] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Accepted: 08/12/2021] [Indexed: 01/10/2023]
Abstract
The mechanistic Target of Rapamycin (mTOR) is a growth-related kinase that, in the context of the mTOR complex 1 (mTORC1), touches upon most fundamental cellular processes. Consequently, its activity is a critical determinant for cellular and organismal physiology, while its dysregulation is commonly linked to human aging and age-related disease. Presumably the most important stimulus that regulates mTORC1 activity is nutrient sufficiency, whereby amino acids play a predominant role. In fact, mTORC1 functions as a molecular sensor for amino acids, linking the cellular demand to the nutritional supply. Notably, dietary restriction (DR), a nutritional regimen that has been shown to extend lifespan and improve healthspan in a broad spectrum of organisms, works via limiting nutrient uptake and changes in mTORC1 activity. Furthermore, pharmacological inhibition of mTORC1, using rapamycin or its analogs (rapalogs), can mimic the pro-longevity effects of DR. Conversely, nutritional amino acid overload has been tightly linked to aging and diseases, such as cancer, type 2 diabetes and obesity. Similar effects can also be recapitulated by mutations in upstream mTORC1 regulators, thus establishing a tight connection between mTORC1 signaling and aging. Although the role of growth factor signaling upstream of mTORC1 in aging has been investigated extensively, the involvement of signaling components participating in the nutrient sensing branch is less well understood. In this review, we provide a comprehensive overview of the molecular and cellular mechanisms that signal nutrient availability to mTORC1, and summarize the role that nutrients, nutrient sensors, and other components of the nutrient sensing machinery play in cellular and organismal aging.
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Affiliation(s)
- Stephanie A. Fernandes
- Max Planck Institute for Biology of Ageing (MPI-AGE), Cologne, Germany
- Cologne Graduate School for Ageing Research (CGA), Cologne, Germany
| | - Constantinos Demetriades
- Max Planck Institute for Biology of Ageing (MPI-AGE), Cologne, Germany
- Cologne Graduate School for Ageing Research (CGA), Cologne, Germany
- University of Cologne, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne, Germany
- *Correspondence: Constantinos Demetriades,
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Boehm P, Martini T, Lee YH, Cacherat B, Morandi B. Palladium-Catalyzed Decarbonylative Iodination of Aryl Carboxylic Acids Enabled by Ligand-Assisted Halide Exchange. Angew Chem Int Ed Engl 2021; 60:17211-17217. [PMID: 34013616 PMCID: PMC8362116 DOI: 10.1002/anie.202103269] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 05/05/2021] [Indexed: 11/08/2022]
Abstract
We report an efficient and broadly applicable palladium-catalyzed iodination of inexpensive and abundant aryl and vinyl carboxylic acids via in situ activation to the acid chloride and formation of a phosphonium salt. The use of 1-iodobutane as iodide source in combination with a base and a deoxychlorinating reagent gives access to a wide range of aryl and vinyl iodides under Pd/Xantphos catalysis, including complex drug-like scaffolds. Stoichiometric experiments and kinetic analysis suggest a unique mechanism involving C-P reductive elimination to form the Xantphos phosphonium chloride, which subsequently initiates an unusual halogen exchange by outer sphere nucleophilic substitution.
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Affiliation(s)
- Philip Boehm
- Laboratorium für Organische ChemieETH ZürichVladimir-Prelog-Weg 3, HCI8093ZürichSwitzerland
| | - Tristano Martini
- Laboratorium für Organische ChemieETH ZürichVladimir-Prelog-Weg 3, HCI8093ZürichSwitzerland
| | - Yong Ho Lee
- Laboratorium für Organische ChemieETH ZürichVladimir-Prelog-Weg 3, HCI8093ZürichSwitzerland
- Max-Planck-Institut für KohlenforschungKaiser-Wilhelm-Platz 145470Mülheim an der RuhrGermany
| | - Bastien Cacherat
- Max-Planck-Institut für KohlenforschungKaiser-Wilhelm-Platz 145470Mülheim an der RuhrGermany
| | - Bill Morandi
- Laboratorium für Organische ChemieETH ZürichVladimir-Prelog-Weg 3, HCI8093ZürichSwitzerland
- Max-Planck-Institut für KohlenforschungKaiser-Wilhelm-Platz 145470Mülheim an der RuhrGermany
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