TY - JOUR A1 - Zupok, Arkadiusz A1 - Iobbi-Nivol, Chantal A1 - Mejean, Vincent A1 - Leimkühler, Silke T1 - The regulation of Moco biosynthesis and molybdoenzyme gene expression by molybdenum and iron in bacteria JF - Metallomics : integrated biometal science N2 - Bacterial molybdoenzymes are key enzymes involved in the global sulphur, nitrogen and carbon cycles. These enzymes require the insertion of the molybdenum cofactor (Moco) into their active sites and are able to catalyse a large range of redox-reactions. Escherichia coli harbours nineteen different molybdoenzymes that require a tight regulation of their synthesis according to substrate availability, oxygen availability and the cellular concentration of molybdenum and iron. The synthesis and assembly of active molybdoenzymes are regulated at the level of transcription of the structural genes and of translation in addition to the genes involved in Moco biosynthesis. The action of global transcriptional regulators like FNR, NarXL/QP, Fur and ArcA and their roles on the expression of these genes is described in detail. In this review we focus on what is known about the molybdenum- and iron-dependent regulation of molybdoenzyme and Moco biosynthesis genes in the model organism E. coli. The gene regulation in E. coli is compared to two other well studied model organisms Rhodobacter capsulatus and Shewanella oneidensis. Y1 - 2019 U6 - https://doi.org/10.1039/c9mt00186g SN - 1756-5901 SN - 1756-591X VL - 11 IS - 10 SP - 1602 EP - 1624 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Zouhar, Jan A1 - Sauer, Michael T1 - Helping hands for budding prospects: ENTH/ANTH/VHS accessory proteins in endocytosis, vacuolar transport, and secretion JF - The plant cell N2 - Coated vesicles provide a major mechanism for the transport of proteins through the endomembrane system of plants. Transport between the endoplasmic reticulum and the Golgi involves vesicles with COPI and COPII coats, whereas clathrin is the predominant coat in endocytosis and post-Golgi trafficking. Sorting of cargo, coat assembly, budding, and fission are all complex and tightly regulated processes that involve many proteins. The mechanisms and responsible factors are largely conserved in eukaryotes, and increasing organismal complexity tends to be associated with a greater numbers of individual family members. Among the key factors is the class of ENTH/ANTH/VHS domain-containing proteins, which link membrane subdomains, clathrin, and other adapter proteins involved in early steps of clathrin coated vesicle formation. More than 30 Arabidopsis thaliana proteins contain this domain, but their generally low sequence conservation has made functional classification difficult. Reports from the last two years have greatly expanded our knowledge of these proteins and suggest that ENTH/ANTH/VHS domain proteins are involved in various instances of clathrin-related endomembrane trafficking in plants. This review aims to summarize these new findings and discuss the broader context of clathrin-dependent plant vesicular transport. Y1 - 2014 U6 - https://doi.org/10.1105/tpc.114.131680 SN - 1040-4651 SN - 1532-298X VL - 26 IS - 11 SP - 4232 EP - 4244 PB - American Society of Plant Physiologists CY - Rockville ER - TY - JOUR A1 - Zhang, Gong A1 - Ignatova, Zoya T1 - Folding at the birth of the nascent chain: coordinating translation with co-translational folding JF - Current opinion in structural biology : review of all advances ; evaluation of key references ; comprehensive listing of papers N2 - In the living cells, the folding of many proteins is largely believed to begin co-translationally, during their biosynthesis at the ribosomes. In the ribosomal tunnel, the nascent peptide may establish local interactions and stabilize alpha-helical structures. Long-range contacts are more likely outside the ribosomes after release of larger segments of the nascent chain. Examples suggest that domains can attain native-like structure on the ribosome with and without population of folding intermediates. The co-translational folding is limited by the speed of the gradual extrusion of the nascent peptide which imposes conformational restraints on its folding landscape. Recent experimental and in silico modeling studies indicate that translation kinetics fine-tunes co-translational folding by providing a time delay for sequential folding of distinct portions of the nascent chain. Y1 - 2011 U6 - https://doi.org/10.1016/j.sbi.2010.10.008 SN - 0959-440X VL - 21 IS - 1 SP - 25 EP - 31 PB - Elsevier CY - London ER - TY - JOUR A1 - Yokoyama, Kenichi A1 - Leimkühler, Silke T1 - The role of FeS clusters for molybdenum cofactor biosynthesis and molybdoenzymes in bacteria JF - Biochimica et biophysica acta : Molecular cell research N2 - The biosynthesis of the molybdenum cofactor (Moco) has been intensively studied, in addition to its insertion into molybdoenzymes. In particular, a link between the assembly of molybdoenzymes and the biosynthesis of FeS clusters has been identified in the recent years: 1) the synthesis of the first intermediate in Moco biosynthesis requires an FeS-cluster containing protein, 2) the sulfurtransferase for the dithiolene group in Moco is also involved in the synthesis of FeS clusters, thiamin and thiolated tRNAs, 3) the addition of a sulfido-ligand to the molybdenum atom in the active site additionally involves a sulfurtransferase, and 4) most molybdoenzymes in bacteria require FeS clusters as redox active cofactors. In this review we will focus on the biosynthesis of the molybdenum cofactor in bacteria, its modification and insertion into molybdoenzymes, with an emphasis to its link to FeS cluster biosynthesis and sulfur transfer. (C) 2014 Elsevier B.V. All rights reserved. KW - Molybdenum-iron-iron-sulfur cluster KW - Molybdenum cofactor KW - tRNA KW - Sulfur transfer KW - L-Cysteine desulfurase Y1 - 2015 U6 - https://doi.org/10.1016/j.bbamcr.2014.09.021 SN - 0167-4889 SN - 0006-3002 VL - 1853 IS - 6 SP - 1335 EP - 1349 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Yarman, Aysu A1 - Scheller, Frieder W. T1 - How reliable is the electrochemical readout of MIP sensors? JF - Sensors N2 - Electrochemical methods offer the simple characterization of the synthesis of molecularly imprinted polymers (MIPs) and the readouts of target binding. The binding of electroinactive analytes can be detected indirectly by their modulating effect on the diffusional permeability of a redox marker through thin MIP films. However, this process generates an overall signal, which may include nonspecific interactions with the nonimprinted surface and adsorption at the electrode surface in addition to (specific) binding to the cavities. Redox-active low-molecular-weight targets and metalloproteins enable a more specific direct quantification of their binding to MIPs by measuring the faradaic current. The in situ characterization of enzymes, MIP-based mimics of redox enzymes or enzyme-labeled targets, is based on the indication of an electroactive product. This approach allows the determination of both the activity of the bio(mimetic) catalyst and of the substrate concentration. KW - molecularly imprinted polymers KW - electropolymerization KW - direct electron KW - transfer KW - catalysis KW - redox marker KW - gate effect Y1 - 2020 U6 - https://doi.org/10.3390/s20092677 SN - 1424-8220 VL - 20 IS - 9 PB - MDPI CY - Basel ER - TY - JOUR A1 - Yarman, Aysu A1 - Jetzschmann, Katharina J. A1 - Neumann, Bettina A1 - Zhang, Xiaorong A1 - Wollenberger, Ulla A1 - Cordin, Aude A1 - Haupt, Karsten A1 - Scheller, Frieder W. T1 - Enzymes as Tools in MIP-Sensors JF - Chemosensors N2 - Molecularly imprinted polymers (MIPs) have the potential to complement antibodies in bioanalysis, are more stable under harsh conditions, and are potentially cheaper to produce. However, the affinity and especially the selectivity of MIPs are in general lower than those of their biological pendants. Enzymes are useful tools for the preparation of MIPs for both low and high-molecular weight targets: As a green alternative to the well-established methods of chemical polymerization, enzyme-initiated polymerization has been introduced and the removal of protein templates by proteases has been successfully applied. Furthermore, MIPs have been coupled with enzymes in order to enhance the analytical performance of biomimetic sensors: Enzymes have been used in MIP-sensors as tracers for the generation and amplification of the measuring signal. In addition, enzymatic pretreatment of an analyte can extend the analyte spectrum and eliminate interferences. KW - enzymatic MIP synthesis KW - template digestion KW - enzyme tracer KW - enzymatic analyte conversion KW - molecularly imprinted polymers Y1 - 2017 U6 - https://doi.org/10.3390/chemosensors5020011 SN - 2227-9040 VL - 5 PB - MDPI CY - Basel ER - TY - JOUR A1 - Yarman, Aysu A1 - Dechtrirat, Decha A1 - Bosserdt, Maria A1 - Jetzschmann, Katharina J. A1 - Gajovic-Eichelmann, Nenad A1 - Scheller, Frieder W. T1 - Cytochrome c-derived hybrid systems based on moleculary imprinted polymers JF - Electroanalysis : an international journal devoted to fundamental and practical aspects of electroanalysis N2 - Hybrid architectures which combine a MIP with an immobilized affinity ligand or a biocatalyst sum up the advantages of both components. In this paper, hybrid architectures combining a layer of a molecularly imprinted electropolymer with a mini-enzyme or a self-assembled monolayer will be presented. (i) Microperoxidase-11 (MP-11) catalyzed oxidation of the drug aminopyrine on a product-imprinted sublayer: The peroxide dependent conversion of the analyte aminopyrine takes place in the MP-11 containing layer on top of a product-imprinted electropolymer on the indicator electrode. The hierarchical architecture resulted in the elimination of interfering signals for ascorbic acid and uric acid. An advantage of the new hierarchical structure is the separation of MIP formation by electropolymerization and immobilization of the catalyst. In this way it was for the first time possible to integrate an enzyme with a MIP layer in a sensor configuration. This combination has the potential to be transferred to other enzymes, e.g. P450, opening the way to clinically important analytes. (ii) Epitope-imprinted poly-scopoletin layer for binding of the C-terminal peptide and cytochrome c (Cyt c): The MIP binds both the target peptide and the parent protein almost eight times stronger than the non-imprinted polymer with affinities in the lower micromolar range. Exchange of only one amino acid in the peptide decreases the binding by a factor of five. (iii) MUA-poly-scopoletin MIP for cytochrome c: Cyt c bound to the MIP covered gold electrode exhibits direct electron transfer with a redox potential and rate constant typical for the native protein. The MIP cover layer suppresses the displacement of the target protein by BSA or myoglobin. The combination of protein imprinted polymers with an efficient electron transfer is a new concept for characterizing electroactive proteins such as Cyt c. The competition with other proteins shows that the MIP binds its target Cyt c preferentially and that molecular shape and the charge of protein determine the binding of interfering proteins. KW - Molecularly imprinted polymers KW - Microperoxidase-11 KW - Cytochrome c KW - Catalytically active MIPs KW - Epitope imprinting KW - Monoclonal MIPs Y1 - 2015 U6 - https://doi.org/10.1002/elan.201400592 SN - 1040-0397 SN - 1521-4109 VL - 27 IS - 3 SP - 573 EP - 586 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Yan, Wenhao A1 - Chen, Dijun A1 - Kaufmann, Kerstin T1 - Molecular mechanisms of floral organ specification by MADS domain proteins JF - Current opinion in plant biology N2 - Flower development is a model system to understand organ specification in plants. The identities of different types of floral organs are specified by homeotic MADS transcription factors that interact in a combinatorial fashion. Systematic identification of DNA-binding sites and target genes of these key regulators show that they have shared and unique sets of target genes. DNA binding by MADS proteins is not based on ‘simple’ recognition of a specific DNA sequence, but depends on DNA structure and combinatorial interactions. Homeotic MADS proteins regulate gene expression via alternative mechanisms, one of which may be to modulate chromatin structure and accessibility in their target gene promoters. Y1 - 2016 U6 - https://doi.org/10.1016/j.pbi.2015.12.004 SN - 1369-5266 SN - 1879-0356 VL - 29 SP - 154 EP - 162 PB - Elsevier CY - London ER - TY - JOUR A1 - Yamamichi, Masato A1 - Klauschies, Toni A1 - Miner, Brooks E. A1 - van Velzen, Ellen T1 - Modelling inducible defences in predator-prey interactions BT - assumptions and dynamical consequences of three distinct approaches JF - Ecology letters N2 - Inducible defences against predation are widespread in the natural world, allowing prey to economise on the costs of defence when predation risk varies over time or is spatially structured. Through interspecific interactions, inducible defences have major impacts on ecological dynamics, particularly predator-prey stability and phase lag. Researchers have developed multiple distinct approaches, each reflecting assumptions appropriate for particular ecological communities. Yet, the impact of inducible defences on ecological dynamics can be highly sensitive to the modelling approach used, making the choice of model a critical decision that affects interpretation of the dynamical consequences of inducible defences. Here, we review three existing approaches to modelling inducible defences: Switching Function, Fitness Gradient and Optimal Trait. We assess when and how the dynamical outcomes of these approaches differ from each other, from classic predator-prey dynamics and from commonly observed eco-evolutionary dynamics with evolving, but non-inducible, prey defences. We point out that the Switching Function models tend to stabilise population dynamics, and the Fitness Gradient models should be carefully used, as the difference with evolutionary dynamics is important. We discuss advantages of each approach for applications to ecological systems with particular features, with the goal of providing guidelines for future researchers to build on. KW - Adaptive dynamics KW - fitness gradient KW - inducible defence KW - optimal trait KW - phenotypic plasticity KW - predator-prey dynamics KW - reaction norm KW - switching function Y1 - 2019 U6 - https://doi.org/10.1111/ele.13183 SN - 1461-023X SN - 1461-0248 VL - 22 IS - 2 SP - 390 EP - 404 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Wozniak, Natalia Joanna A1 - Sicard, Adrien T1 - Evolvability of flower geometry BT - Convergence in pollinator-driven morphological evolution of flowers JF - Seminars in cell & developmental biology N2 - Flowers represent a key innovation during plant evolution. Driven by reproductive optimization, evolution of flower morphology has been central in boosting species diversification. In most cases, this has happened through specialized interactions with animal pollinators and subsequent reduction of gene flow between specialized morphs. While radiation has led to an enormous variability in flower forms and sizes, recurrent evolutionary patterns can be observed. Here, we discuss the targets of selection involved in major trends of pollinator-driven flower evolution. We review recent findings on their adaptive values, developmental grounds and genetic bases, in an attempt to better understand the repeated nature of pollinator-driven flower evolution. This analysis highlights how structural innovation can provide flexibility in phenotypic evolution, adaptation and speciation. (C) 2017 Elsevier Ltd. All rights reserved. KW - Flower KW - Developmental evolution KW - Morphogenesis KW - Angiosperms KW - Co-evolution KW - Plant-pollinator interactions Y1 - 2018 U6 - https://doi.org/10.1016/j.semcdb.2017.09.028 SN - 1084-9521 VL - 79 SP - 3 EP - 15 PB - Elsevier CY - London ER -