Reciprocal regulation of protein synthesis and carbon metabolism for thylakoid membrane biogenesis

Metabolic control of gene expression coordinates the levels of specific gene products to meet cellular demand for their activities. This control can be exerted by metabolites acting as regulatory signals and/or a class of metabolic enzymes with dual functions as regulators of gene expression. However, little is known about how metabolic signals affect the balance between enzymatic and regulatory roles of these dual functional proteins. We previously described the RNA binding activity of a 63 kDa chloroplast protein from Chlamydomonas reinhardtii, which has been implicated in expression of the psbA mRNA, encoding the D1 protein of photosystem II. Here, we identify this factor as dihydrolipoamide acetyltransferase (DLA2), a subunit of the chloroplast pyruvate dehydrogenase complex (cpPDC), which is known to provide acetyl-CoA for fatty acid synthesis. Analyses of RNAi lines revealed that DLA2 is involved in the synthesis of both D1 and acetyl-CoA. Gel filtration analyses demonstrated an RNP complex containing DLA2 and the chloroplast psbA mRNA specifically in cells metabolizing acetate. An intrinsic RNA binding activity of DLA2 was confirmed by in vitro RNA binding assays. Results of fluorescence microscopy and subcellular fractionation experiments support a role of DLA2 in acetate-dependent localization of the psbA mRNA to a translation zone within the chloroplast. Reciprocally, the activity of the cpPDC was specifically affected by binding of psbA mRNA. Beyond that, in silico analysis and in vitro RNA binding studies using recombinant proteins support the possibility that RNA binding is an ancient feature of dihydrolipoamide acetyltransferases. Our results suggest a regulatory function of DLA2 in response to growth on reduced carbon energy sources. This raises the intriguing possibility that this regulation functions to coordinate the synthesis of lipids and proteins for the biogenesis of photosynthetic membranes

ACUTE EFFECTS OF DIFFERENT CUSHIONED FOOTWEAR ON THE BIOMECHANICS OF RUNNING

The purpose of this study was to investigate how different footwear (highly cushioned, standard, minimalist shoes) affect peak ground reaction forces, average loading rates and joint kinematics during running. Nine participants ran at a self-selected speed across all shod conditions, minimalist, highly cushioned and standard running shoe. Vicon Nexus was used to analyze joint kinematics of the ankle and knee, a Bertec Instrumented Treadmill was used to analyze the average loading rate and peak ground reaction forces. Results show consist of reductions in ankle and knee joint motion in the minimalist shoe during the stance phase with the standard and highly cushioned shoe being more similar to each other. Evidence suggests that a change in footwear alone, at least in the short-term, will not reducing injury rates in runners

The online inverted classroom model (oICM): a blueprint to adapt the inverted classroom to an online learning setting in medical and health education [version 2]

This article was migrated. The article was marked as recommended. The idea of this paper is to offer a blueprint, to guide educators setting up a complete digital teaching scenario according to the latest insights of educational research. The COVID-19 pandemic forced higher education institutions all around the world to radically shift their curricula from a mix of face-to-face and remote teaching methods to a fully remote curriculum. Though challenging, this time provides opportunities to implement new educational methods and to improve the quality of digital teaching. The concept of the inverted classroom was modified to meet the special needs of the new online settings. The proposed online Inverted Classroom Model (oICM) includes the following phases: (1) pre-phase, (2) self-learning-phase, (3) synchronous online phase, (4) transfer-phase, and (5) evaluation. Recommendations and potential tools are provided for each phase. The oICM is an innovative and easy to use approach to shape digital teaching and learning processes during and after the COVID-19 pandemic. This blueprint is developed by the committee “Digitalization” of the German Association for Medical Education (GMA), mainly for educators who are familiar with the Inverted Classroom Model (ICM) or similar blended learning formats

Structure of the Extracellular Portion of CD46 Provides Insights into Its Interactions with Complement Proteins and Pathogens

The human membrane cofactor protein (MCP, CD46) is a central component of the innate immune system. CD46 protects autologous cells from complement attack by binding to complement proteins C3b and C4b and serving as a cofactor for their cleavage. Recent data show that CD46 also plays a role in mediating acquired immune responses, and in triggering autophagy. In addition to these physiologic functions, a significant number of pathogens, including select adenoviruses, measles virus, human herpes virus 6 (HHV-6), Streptococci, and Neisseria, use CD46 as a cell attachment receptor. We have determined the crystal structure of the extracellular region of CD46 in complex with the human adenovirus type 11 fiber knob. Extracellular CD46 comprises four short consensus repeats (SCR1-SCR4) that form an elongated structure resembling a hockey stick, with a long shaft and a short blade. Domains SCR1, SCR2 and SCR3 are arranged in a nearly linear fashion. Unexpectedly, however, the structure reveals a profound bend between domains SCR3 and SCR4, which has implications for the interactions with ligands as well as the orientation of the protein at the cell surface. This bend can be attributed to an insertion of five hydrophobic residues in a SCR3 surface loop. Residues in this loop have been implicated in interactions with complement, indicating that the bend participates in binding to C3b and C4b. The structure provides an accurate framework for mapping all known ligand binding sites onto the surface of CD46, thereby advancing an understanding of how CD46 acts as a receptor for pathogens and physiologic ligands of the immune system

Plasticity of the β-Trefoil Protein Fold in the Recognition and Control of Invertebrate Predators and Parasites by a Fungal Defence System

Discrimination between self and non-self is a prerequisite for any defence mechanism; in innate defence, this discrimination is often mediated by lectins recognizing non-self carbohydrate structures and so relies on an arsenal of host lectins with different specificities towards target organism carbohydrate structures. Recently, cytoplasmic lectins isolated from fungal fruiting bodies have been shown to play a role in the defence of multicellular fungi against predators and parasites. Here, we present a novel fruiting body lectin, CCL2, from the ink cap mushroom Coprinopsis cinerea. We demonstrate the toxicity of the lectin towards Caenorhabditis elegans and Drosophila melanogaster and present its NMR solution structure in complex with the trisaccharide, GlcNAcβ1,4[Fucα1,3]GlcNAc, to which it binds with high specificity and affinity in vitro. The structure reveals that the monomeric CCL2 adopts a β-trefoil fold and recognizes the trisaccharide by a single, topologically novel carbohydrate-binding site. Site-directed mutagenesis of CCL2 and identification of C. elegans mutants resistant to this lectin show that its nematotoxicity is mediated by binding to α1,3-fucosylated N-glycan core structures of nematode glycoproteins; feeding with fluorescently labeled CCL2 demonstrates that these target glycoproteins localize to the C. elegans intestine. Since the identified glycoepitope is characteristic for invertebrates but absent from fungi, our data show that the defence function of fruiting body lectins is based on the specific recognition of non-self carbohydrate structures. The trisaccharide specifically recognized by CCL2 is a key carbohydrate determinant of pollen and insect venom allergens implying this particular glycoepitope is targeted by both fungal defence and mammalian immune systems. In summary, our results demonstrate how the plasticity of a common protein fold can contribute to the recognition and control of antagonists by an innate defence mechanism, whereby the monovalency of the lectin for its ligand implies a novel mechanism of lectin-mediated toxicity

Development and analysis of the Soil Water Infiltration Global database

In this paper, we present and analyze a novel global database of soil infiltration measurements, the Soil Water Infiltration Global (SWIG) database. In total, 5023 infiltration curves were collected across all continents in the SWIG database. These data were either provided and quality checked by the scientists who performed the experiments or they were digitized from published articles. Data from 54 different countries were included in the database with major contributions from Iran, China, and the USA. In addition to its extensive geographical coverage, the collected infiltration curves cover research from 1976 to late 2017. Basic information on measurement location and method, soil properties, and land use was gathered along with the infiltration data, making the database valuable for the development of pedotransfer functions (PTFs) for estimating soil hydraulic properties, for the evaluation of infiltration measurement methods, and for developing and validating infiltration models. Soil textural information (clay, silt, and sand content) is available for 3842 out of 5023 infiltration measurements ( ∼ 76%) covering nearly all soil USDA textural classes except for the sandy clay and silt classes. Information on land use is available for 76% of the experimental sites with agricultural land use as the dominant type ( ∼ 40%). We are convinced that the SWIG database will allow for a better parameterization of the infiltration process in land surface models and for testing infiltration models. All collected data and related soil characteristics are provided online in *.xlsx and *.csv formats for reference, and we add a disclaimer that the database is for public domain use only and can be copied freely by referencing it. Supplementary data are available at https://doi.org/10.1594/PANGAEA.885492 (Rahmati et al., 2018). Data quality assessment is strongly advised prior to any use of this database. Finally, we would like to encourage scientists to extend and update the SWIG database by uploading new data to it

Das Projekt eines Umweltgesetzbuchs 2009

Der Band dokumentiert eine von der Humboldt-Universität zu Berlin, dem Forschungs-zentrum Umweltrecht (Berlin) und von der Deutschen Hochschule für Verwaltungswissen-schaften Speyer organisierte wissenschaftliche Tagung zum ministeriellen Entwurf eines Umweltgesetzbuchs 2009 (UGB 2009). Mit diesem in der Tradition anderer großer Kodifika-tionen wie dem Bürgerlichen Gesetzbuch oder den Büchern des Sozialgesetzbuchs stehen-den Gesetzbuch sollte das zersplitterte deutsche Umweltrecht jedenfalls teilweise zusam-mengefasst und damit anwenderfreundlicher gestaltet werden. Zwar konnte das UGB in der 16. Legislaturperiode als Gesamtvorhaben politisch wegen des im Frühjahr 2009 aufziehen-den Wahlkampfs nicht mehr realisiert werden. Auf Grund der nach wie vor bestehenden Umweltrechtszersplitterung und der damit einhergehenden Unübersichtlichkeit der Rechts-materie hat das Projekt eines Umweltgesetzbuchs gleichwohl nicht an Aktualität verloren. Der Tagungsband enthält Beiträge aus Rechtswissenschaft, Verwaltung, Ministerien und Politik. Von den Autoren werden darin die Notwendigkeit einer Kodifikation als Mittel zur guten Gesetzgebung und als Beitrag zur Entbürokratisierung, aber auch politische und verfassungsrechtliche Rahmenbedingungen für eine Umweltrechtskodifikation beleuchtet. Andere Autoren befassen sich mit der während der Entwurfserarbeitung besonders um-strittenen integrierten Vorhabengenehmigung. Daneben werden die besonderen Teile des Entwurfs z. B. über das Wasserrecht und das Naturschutzrecht sowie die Folgen einer Umweltrechtskodifikation für das nicht-kodifizierte Umweltrecht und das Umweltrecht der Länder diskutiert. Zuletzt bietet der Band mit dem Protokoll der abschließenden Podiums-diskussion einen Einblick in die Standpunkte der Industrie- und Umweltverbände zum Projekt eines Umweltgesetzbuchs

Avalanches keep habitats open and species-rich in the montane and subalpine belt. eco.mont (Journal on Protected Mountain Areas Research)|eco.mont Vol. 2 No. 1 2 1|

From a conservation point of view, avalanches are a natural ecological process. However, they can also endanger people and cause serious damage to buildings and infrastructure. From an anthropocentric point of view, protective measures in the form of avalanche barriers are necessary. Avalanche barriers in the starting zone of avalanches can prevent avalanche events. Hence there is a conflict between nature conservation and protection against natural hazards. This study aimed primarily at assessing the conservation value of active avalanche tracks. To this end we examined 16 plant stands on three different avalanche tracks in the Gesäuse National Park (Styria, Austria) and recorded butterfly species at the same time. On the investigated avalanche tracks, the soils are very shallow, stony, periodically dry, nutrient-poor, base-rich rendzinas developed over limestone debris. The sites are scree-covered, steep and mainly east-facing slopes located in the montane belt. The plant stands investigated belong mainly to the Origano-Calamagrostietum variae community. This study of biodiversity concludes that under these conditions the vegetation in active avalanche tracks is characterized by a high richness of vascular plant species. On average, a plot size of 20 m² contains 71 vascular plant species and 5 bryophyte species. The species-rich plant stands, colourful when in bloom, are dominated by herbs, resulting in a high aesthetic value and an increased diversity of butterflies. The avalanche tracks investigated have a high conservation value because natural ecological processes continue to happen, leading to near-natural and species-rich disclimax communities