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Classical zinc fingers domains (ZFs) bind Zn(II) ion by a pair of cysteine and histidine residues to adopt a characteristic and stable ββα fold containing a small hydrophobic core. As a component of transcription factors, they recognize specific DNA sequences to transcript particular genes. The loss of Zn(II) disrupts the unique structure and function of the whole protein. It has been shown that the saturation of ZFs under cellular conditions is strictly related to their affinity for Zn(II). High affinity warrants their constant saturation, while medium affinity results in their transient structurization depending on cellular zinc availability. Therefore, there must be factors hidden in the sequence and structure of ZFs that impact Zn(II)-to-protein affinities to control their function. Using molecular dynamics simulations and experimental spectroscopic and calorimetric approaches, we showed that particular non-conserved residues derived from ZF sequences impact hydrogen bond formation. Our in silico and in vitro studies show that non-conserved residues can alter metal-coupled folding mechanisms and overall ZF stability. Furthermore, we show that Zn(II) binding to ZFs can also be entropically driven. This preference does not correlate either with Zn(II) binding site or with the extent of the secondary structure but is strictly related to a reservoir of interactions within the second coordination shell, which may loosen or tighten up the structure. Our findings shed new light on how the functionality of ZFs is modulated by non-coordinating residues diversity under cellular conditions. Moreover, they can be helpful for systematic backbone alteration of native ZF ββα scaffold to create artificial foldamers and proteins with improved stability.

International audience; Silver (Ag(I)) binding to consensus zinc fingers (ZFs) causes Zn(II) release inducing a gradual disruption of the hydrophobic core, followed by an overall conformational change and formation of highly stable AgnSn clusters. A compact eight-membered Ag4S4 structure formed by a CCCC ZF is the first cluster example reported for a single biological molecule. Ag(I)-induced conformational changes of ZFs can, as a consequence, affect transcriptional regulation and other cellular processes.

High Ambrosia pollen concentrations in Poland rather rarely come from the local sources. The aim of this study was to define the temporal and spatial differences of the high Ambrosia pollen concentrations by creating models for the pollen transport from the distant sources. This study was thought to determine the direction of the air masses inflow into Poland, carrying Ambrosia pollen, from areas of the bordering countries with the pollen concentrations higher than iSTOTEN_n Poland. Pollen and meteorological datasets at 8 monitoring sites in Poland, and daily pollen concentrations at 11 sites in the Czech Republic, 5 sites in Slovakia and 3 sites in Ukraine were analysed recently. Days with concentrations ≥10 Pollen/m3 and concurrent meteorological situations were analysed in great deal. The HYSPLIT model was applied to compute backward trajectories up to 4 days backward (96 h) and at three altitudes: 20, 500 and 1000 m above ground level (a.g.l.). High pollen concentrations occur most frequently when the air masses inflow into Poland from southerly (S, SE, SW, 44%) and easterly (E, 6%) directions and in no advection situations (25%). In years with the highest frequency of days over 10 Pollen/m3, the prevailing directions of the pollen influx into Poland were from the South (2004–2006, 2008, 2011) but in one year (2014) from the East. Trajectories for the studied period show that air masses come most frequently from Slovakia and the Czech Republic. Sometimes, the Ambrosia pollen transport happens from Ukraine.

Silver (Ag(i)) binding to consensus zinc fingers (ZFs) causes Zn(ii) release inducing a gradual disruption of the hydrophobic core, followed by an overall conformational change and formation of highly stable Ag

Urban green spaces, especially urban parks, are essential for the proper functioning of cities, but they can be a serious source of airborne fungal spores. Aerobiological monitoring was carried out in urban parks of different typology to estimate the risk associated with fungal spores for citizens. Volumetric method was applied with the use of portable Burkard Sampler. In the air of the studied parks, the most dominant spores are strong allergenic or considered as potentially allergenic. Cladosporium spores were found in enormous concentrations in all studied parks, and it affected the low biodiversity of fungal spores in the parks. Compared to Cladosporium, concentrations of Alternaria spores in the air were several dozen times lower, but still a risk for people who are allergic. The fungal spores spectra and their seasonal occurrence in each park were similar. The highest similarities in the patterns of the season were found in the case of Cladosporium, Alternaria, Epicoccum, and the lowest in the case of Torula and Drechslera type. Due to the fact that allergy sufferers are most often polysensitized, the period when they should limit long visits in the urban parks is July–August, when the concentration of allergenic fungal spores of many taxa is the highest.

Atmospheric precipitation removes the majority of biological and chemical pollutants from the lower parts of the troposphere. However, some studies infer increasing atmospheric pollen concentrations during precipitation events and/or thunderstorms, which are known to trigger allergic reactions (referred to as thunderstorm-triggered asthma). The aim of this study was to determine the impacts of precipitation on the diurnal variability of airborne pollen concentrations, with particular focus on the timing and intensity of precipitation events. We also considered the impacts of other meteorological elements on atmospheric pollen concentrations. The research was conducted in Rzeszow (SE Poland) from 2016 to 2018. We used two aerobiological and two meteorological stations in this study to determine potential spatial variability in the pollen response to rainfall, the diurnal precipitation changes, and the precipitation intensity in the city area. We determined the pollen response of four pollen types: Betula, Pinus, Poaceae, and Urtica, and we only included data from days that fulfilled restrictive criteria throughout all pollen seasons. We analysed a total of 81 days, which were divided into five groups according to precipitation intensity, the time of day of a precipitation event, and the type of pollen response to precipitation. Our results suggest that precipitation intensity was the dominant control on pollen concentrations; concentrations only decreased clearly under rainfall intensities of at least 5 mm•h−1 and this value we recommended as threshold value for long lasting decrease of pollen concentrations in our region. Lower intensity rainfall events resulted in no change in atmospheric pollen concentrations throughout the day. We noted the occurrence of increased pollen concentration immediately before and during rainfall events. Further, other parameters were also found to influence pollen concentrations in the atmosphere, including relative humidity, the time of day, and biological factors such as the plant phenophase or the phase of a pollen season.

Unidad de excelencia María de Maeztu CEX2019-000940-M Annually variable and synchronous seed production, or masting, is often correlated with environmental factors and in oaks involves differential pollination success that depends on phenological synchrony in flowering. The synchronization of phenology of flowering was thought to be driven by temperature during flowering (microclimatic hypothesis). We tested an alternative, whereby phenological synchronization is driven by the timing of the onset of flowering (photoperiod-sensitivity hypothesis). This hypothesis assumes that flowering synchrony is driven by interaction between daylength and temperature, and individual variation in sensitivity to daylength as a phenological cue. We used long-term (23-26 years) records of airborne pollen in Quercus robur, Q. petraea, Q. ilex, and Q. humilis. Late pollen seasons were short, as predicted by photoperiod-sensitivity hypothesis. The onset of pollen seasons was delayed as preseason temperatures cooled over the last three decades at our Mediterranean sites, which was paralleled by shortening in pollen seasons, providing additional support for the photoperiod-sensitivity hypothesis. Global warming under the microclimatic hypothesis is predicted to lead to less frequent reproductive failures and thus decreased variability and synchrony of mast seeding. In contrast, warming under the photoperiod-sensitivity hypothesis should advance the onset of and desynchronize flowering, a pattern supported by our data. This pattern suggests that global warming will lead to more frequent vetoes and more stochastic and variable patterns of oak reproduction.

Zinc fingers (ZFs) are among the most structurally diverse protein domains. They interact with nucleic acids, other proteins and lipids to facilitate a multitude of biological processes. Currently, there are more than 10 known classes of ZFs, with various architectures, metal binding modes, functions and reactivity. The versatility, selectivity and stability of these short amino acid sequences is achieved mainly by (i) residues participating in Zn(II) coordination (mostly Cys and His), (ii) hydrophobic core and ZF structure formation, and (iii) variable residues responsible for inter- and intramolecular interactions. Since their discovery, ZFs have been extensively studied in terms of their structure, stability and recognition targets by the application of various methodologies. Studies based on interactions with other metal ions and their complexes have contributed to the understanding of their chemical properties and the discovery of new types of ZF complexes, such as gold fingers or lead fingers. Moreover, due to the presence of nucleophilic thiolates, ZFs are targets for reactive oxygen and nitrogen species as well as alkylating agents. Interactions with many reactive molecules lead to disturb the native Zn(II) coordination site which further result in structural and functional damage of the ZFs. The post-translational modifications including phosphorylation, acetylation, methylation or nitrosylation frequently affect ZFs function via changes in the protein structure and dynamics. Even though the literature is replete with structural and stability data regarding classical (ββα) ZFs, there is still a huge gap in the knowledge on physicochemical properties and reactivity of other ZF types. In this review, metal binding properties of ZFs and stability factors that modulate their functions are reviewed. These include interactions of ZFs with biogenic and toxic metal ions as well as damage occurring upon reaction with reactive oxygen and nitrogen species, the methodology used for ZFs characterization, and aspects related to coordination chemistry.

Urban water bodies are an important asset in terms of climate change. The accompanying vegetation is an integral part of the waterside space system and a source of ecosystem services and disservices. The composition of greenery in waterside spaces should therefore be preceded by detailed research. This research would be the basis for the development of recommendations for enhancement of the positive impact of vegetation on humans and minimisation of its negative effect. The aim of the study was to identify ecosystem services and disservices of vegetation in the four most important waterside recreation spaces in the city of Rzeszów, Poland, and to develop plant composition guidelines. A detailed inventory of vegetation and aerobiological monitoring of the presence of airborne allergenic pollen grains and fungal spores were carried out. Next, the ecosystem services and disservices of the vegetation were determined based on literature data and on our expert judgement. Additionally, a counting of the number of visitors to waterside areas was conducted. All these steps were used to develop recommendations for shaping the vegetation of study areas. The results of the investigations show that the boulevards along the artificial lake function completely differently than other investigated places as the area resembles an urban park, and the water is not the main attraction in this space. The vegetation of the boulevards and the nearby gravel-pit bathing area has mostly a spontaneous character and offers the widest range of ecosystem services and disservices. The management of the vegetation should focus on its health-enhancing values. The vegetation growing near the outdoor swimming pools has been designed by man. Nevertheless, it requires recomposing and is targeted specifically at the enhancement of the visual attractiveness. Additionally, there is a need for planting compact deciduous trees that will provide shade at the multi-media fountain.

Metal ions are essential elements present in biological systems able to facilitate many cellular processes including proliferation, signaling, DNA synthesis and repair. Zinc ion (Zn(II)) is an important cofactor for numerous biochemical reactions. Commonly, structural zinc sites demonstrate high Zn(II) affinity and compact architecture required for sequence-specific macromolecule binding. However, how Zn(II)-dependent proteins fold, how their dissociation occurs, and which factors modulate zinc protein affinity as well as stability remains not fully understood. The molecular rules governing precise regulation of zinc proteins function are hidden in the relationship between sequence and structure, and hence require deep understanding of their folding mechanism under metal load, reactivity and metal-to-protein affinity. Even though, this sequence-structure relationship has an impact on zinc proteins function, it has been shown that other biological factors including cellular localization and Zn(II) availability influence overall protein behavior. Taking into account all of the mentioned factors, in this review, we aim to describe the relationship between structure-function-stability of zinc structural sites, found in a zinc finger, zinc hook and zinc clasps, and reach far beyond a structural point of view in order to appreciate the balance between chemistry and biology that govern the protein world.

Zinc fingers (ZFs) are among the most abundant motifs found in proteins, and are commonly known for their structural role. Classical ZFs (CCHH) are part of the transcription factors that participate in DNA binding. Although biochemical studies of classical ZFs have a long history, there is limited knowledge about the sequential and structural diversity of ZFs. We have found that classical ZFs, with metal binding sites consisting of amino acids other than conserved Cys or His residues, are frequently encoded in the human genome, and we refer to these peptides as ZFs with a naturally altered metal binding site. The biological role of the altered ZFs remains undiscovered. In this study, we characterized nine natural XCHH, CXHH, CCXH and CCHX ZFs in terms of their Zn(ii) and Co(ii) binding properties, such as complex stoichiometry, spectroscopic properties and metal-to-peptide affinity. We revealed that XCHH and CXHH ZFs form ML complexes that are 4-5 orders of magnitude weaker in comparison to CCHH ZFs. Nevertheless, spectroscopic studies demonstrate that, depending on the altered position, they may adopt an open coordination geometry with one or two water molecules bound to a central metal ion, which has not been demonstrated in natural ZFs before. Stability data show that both CCXH and CCHX peptides have high Zn(ii) affinity (with a Kd of 10-9 to 10-11 M), suggesting their potential biological function. This study is a comprehensive overview of the relationship between the sequence, structure, and stability of ZFs.