Eco-collective

Today’s architecture is no longer an isolated field of building design, but concerns human related issues including sociology and psychology and moreover climate adaptation, ecology, sustainability and technological innovation. Taking point of departure in intensification of precipitation due to the climate change in Denmark, this thesis project attempts to investigate the possibility of establishing a new type of community based on mutual respect and beneficial relationship between architecture, urbanism, human beings and nature. Throughout a set of rules concerning energy conserving landscape, rainwater runoff connected to the climate change and benefits of native vegetation, the project envisions building and landscape design equipped for environmental climate changes and encouraging social interaction. Located on wetlands between Søndersø lake and the old military air base in Værløse, outside of Copenhagen, the thesis proposes a living space for a community situated on top of a frequently flooded area and challenges the negative perception of humidity and intensified precipitation that is commonly associated with the Danish climate, in an attempt to embrace and enhance the subtle beauty of these natural conditions evident within the area

Intracellular shuttling of a Drosophila APC tumour suppressor homolog

RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are.Abstract Background The Adenomatous polyposis coli (APC) tumour suppressor is found in multiple discrete subcellular locations, which may reflect sites of distinct functions. In Drosophila epithelial cells, the predominant APC relative (E-APC) is concentrated at the apicolateral adherens junctions. Genetic analysis indicates that this junctional association is critical for the function of E-APC in Wnt signalling and in cellular adhesion. Here, we ask whether the junctional association of E-APC is stable, or whether E-APC shuttles between the plasma membrane and the cytoplasm. Results We generated a Drosophila strain that expresses E-APC (dAPC2) tagged with green fluorescent protein (GFP-E-APC) and we analysed its junctional association with fluorescence recovery after photobleaching (FRAP) experiments in live embryos. This revealed that the junctional association of GFP-E-APC in epithelial cells is highly dynamic, and is far less stable than that of the structural components of the adherens junctions, E-cadherin, α-catenin and Armadillo. The shuttling of GFP-E-APC to and from the plasma membrane is unaltered in mutants of Drosophila glycogen synthase kinase 3 (GSK3), which mimic constitutive Wingless signalling. However, the stability of E-APC is greatly reduced in these mutants, explaining their apparent delocalisation from the plasma membrane as previously observed. Finally, we show that GFP-E-APC forms dynamic patches at the apical plasma membrane of late embryonic epidermal cells that form denticles, and that it shuttles up and down the axons of the optic lobe. Conclusions We conclude that E-APC is a highly mobile protein that shuttles constitutively between distinct subcellular locations.Published versio

The Adenomatous polyposis coli tumour suppressor is essential for Axin complex assembly and function and opposes Axin's interaction with Dishevelled

Most cases of colorectal cancer are linked to mutational inactivation of the Adenomatous polyposis coli (APC) tumour suppressor. APC downregulates Wnt signalling by enabling Axin to promote the degradation of the Wnt signalling effector β-catenin (Armadillo in flies). This depends on Axin's DIX domain whose polymerization allows it to form dynamic protein assemblies (‘degradasomes’). Axin is inactivated upon Wnt signalling, by heteropolymerization with the DIX domain of Dishevelled, which recruits it into membrane-associated ‘signalosomes’. How APC promotes Axin's function is unclear, especially as it has been reported that APC's function can be bypassed by overexpression of Axin. Examining apc null mutant Drosophila tissues, we discovered that APC is required for Axin degradasome assembly, itself essential for Armadillo downregulation. Degradasome assembly is also attenuated in APC mutant cancer cells. Notably, Axin becomes prone to Dishevelled-dependent plasma membrane recruitment in the absence of APC, indicating a crucial role of APC in opposing the interaction of Axin with Dishevelled. Indeed, co-expression experiments reveal that APC displaces Dishevelled from Axin assemblies, promoting degradasome over signalosome formation in the absence of Wnts. APC thus empowers Axin to function in two ways—by enabling its DIX-dependent self-assembly, and by opposing its DIX-dependent copolymerization with Dishevelled and consequent inactivation

Analiza i projektowanie oscylatorów kwarcowych pracujących w układzie Pierce'a-Colpitts'a. Referaty Problemowe, 1980, zeszyt 28

W referacie przeprowadzono analizę pracy oscylatora kwarcowego (układ Pierce'a-Colpitts'a), z rezonatorem pracującym na częstotliwości podstawowej. Podana została również metoda projektowania układu oraz program w języku BASIC, za pomocą którego można obliczyć wartości elementów

Feedback control of Wnt signaling based on ultrastable histidine cluster co-aggregation between Naked/NKD and Axin.

Feedback control is a universal feature of cell signaling pathways. Naked/NKD is a widely conserved feedback regulator of Wnt signaling which controls animal development and tissue homeostasis. Naked/NKD destabilizes Dishevelled, which assembles Wnt signalosomes to inhibit the β-catenin destruction complex via recruitment of Axin. Here, we discover that the molecular mechanism underlying Naked/NKD function relies on its assembly into ultra-stable decameric core aggregates via its conserved C-terminal histidine cluster (HisC). HisC aggregation is facilitated by Dishevelled and depends on accumulation of Naked/NKD during prolonged Wnt stimulation. Naked/NKD HisC cores co-aggregate with a conserved histidine cluster within Axin, to destabilize it along with Dishevelled, possibly via the autophagy receptor p62, which binds to HisC aggregates. Consistent with this, attenuated Wnt responses are observed in CRISPR-engineered flies and human epithelial cells whose Naked/NKD HisC has been deleted. Thus, HisC aggregation by Naked/NKD provides context-dependent feedback control of prolonged Wnt responses

The kunitz domain protein BLI-5 plays a functionally conserved role in cuticle formation in a diverse range of nematodes

The cuticle of parasitic nematodes performs many critical functions and is essential for proper development and for protection from the host immune response. The biosynthesis, assembly, modification and turnover of this exoskeleton have been most extensively studied in the free-living nematode, Caenorhabditis elegans, where it represents a complex multi-step process involving a whole suite of enzymes. The biosynthesis of the cuticle has an additional level of complexity, as many of the enzymes also require additional proteins to aid their activation and selective inhibition. Blister-5 (BLI-5) represents a protein with a kunitz-type serine protease interacting domain and is involved in cuticle collagen biosynthesis in C. elegans, through its interaction with subtilisin-like processing enzymes (such as BLI-4). Mutation of the bli-5 gene causes blistering of the collagenous adult cuticle. Homologues of BLI-5 have been identified in several parasitic species that span different nematode clades. In this study, we molecularly and biochemically characterize BLI-5 homologues from the clade V nematodes C. elegans and Haemonchus contortus and from the clade III filarial nematode Brugia malayi. The nematode BLI-5 orthologues possess a shared domain structure and perform similar in vitro and in vivo functions, performing important proteolytic enzyme functions. The results demonstrate that the bli-5 genes from these diverse parasitic nematodes are able to complement a C. elegansbli-5 mutant and thereby support the use of the C. elegans model system to examine gene function in the experimentally less-amenable parasitic species

Selective function of the PDZ domain of Dishevelled in noncanonical Wnt signalling

Dishevelled is a cytoplasmic hub that transduces Wnt signals to cytoplasmic effectors, which can be broadly characterised as canonical (β-catenin dependent) and noncanonical, to specify cell fates and behaviours during development. To transduce canonical Wnt signals, Dishevelled binds to the intracellular face of Frizzled through its DEP domain and polymerises through its DIX domain to assemble dynamic signalosomes. Dishevelled also contains a PDZ domain, whose function remains controversial. Here, we use genome editing to delete the PDZ domain-encoding region from Drosophila dishevelled. Canonical Wingless signalling is entirely normal in these deletion mutants; however, they show defects in multiple contexts controlled by noncanonical Wnt signalling, such as planar polarity. We use nuclear magnetic resonance spectroscopy to identify bona fide PDZ-binding motifs at the C termini of different polarity proteins. Although deletions of these motifs proved aphenotypic in adults, we detected changes in the proximodistal distribution of the polarity protein Flamingo (also known as Starry night) in pupal wings that suggest a modulatory role of these motifs in polarity signalling. We also provide new genetic evidence that planar polarity relies on the DEP-dependent recruitment of Dishevelled to the plasma membrane by Frizzled

Anomalous Immunogenic Properties of Serine Proteases

It has previously been shown that a similar to 27 kDa serine protease of Schistosoma mansoni larvae, the cercarial elastase (CE), was a poor immunogen in as much as it failed to induce an antibody response. The CE has a critical role in enabling schistosome larvae to penetrate the skin of their definitive hosts, so the apparently poor immunogenicity of this enzyme is clearly of interest. To understand its lack of immunogenicity better and in particular to determine whether it is related to its proteolytic activity, we have measured antibody responses of mice to three different serine proteases. Groups of mice were immunized with porcine pancreatic trypsin (TRY), chymotrypsin (CHY) or elastase (ELA) and the resulting antibody response compared with antibody responses to two non-protease antigens, chicken egg albumin (OVA) and Schistosoma japonicum glutathione S-transferase (GST), all being administered with alum as an adjuvant. Of 12 mice that were injected five times at 14 day intervals with TRY, only one produced antibody reactive with this enzyme in ELISA. Immunizations with CHY or ELA induced somewhat better antibody responses than TRY, but the responses to the first and second injections of these two proteases nevertheless seemed comparatively lower than the responses to GST. Induction of antibody responses by OVA and GST was not affected when TRY was injected concomitantly. Thus, the antibody response to one of the serine proteases used in this study, mammalian trypsin, was anomalous