Search results for " DOM"
showing 10 items of 2750 documents
Bio-Sintering/Bio-Fusion of Silica in Sponge Spicules
2012
The synthesis of siliceous spicules in both demosponges and hexactinellids is enzymatically driven via silicatein. This enzyme exists both intra-spicularly and in the extra-spicular space. It catalyzes the formation of bio-silica constituting the silica lamellae that are formed during the appositional (layer-by-layer) growth of the spicules. The extent of (bio-silica forming) activity of silicatein from the demosponge Suberites domuncula measured in vitro reflects the amount of bio-silica required for the formation of spicules in vivo. It is shown that during growth and maturation of the spicules in demosponges a bio-fusion process occurs that results in an intra-spicular sintering of the s…
Stimulus Perception in Bacterial Signal-Transducing Histidine Kinases
2006
SUMMARY Two-component signal-transducing systems are ubiquitously distributed communication interfaces in bacteria. They consist of a histidine kinase that senses a specific environmental stimulus and a cognate response regulator that mediates the cellular response, mostly through differential expression of target genes. Histidine kinases are typically transmembrane proteins harboring at least two domains: an input (or sensor) domain and a cytoplasmic transmitter (or kinase) domain. They can be identified and classified by virtue of their conserved cytoplasmic kinase domains. In contrast, the sensor domains are highly variable, reflecting the plethora of different signals and modes of sens…
Flashing light in sponges through their siliceous fiber network: A new strategy of “neuronal transmission” in animals
2012
Sponges (phylum Porifera) represent a successful animal taxon that evolved prior to the Ediacaran-Cambrian boundary (542 million years ago). They have developed an almost complete array of cell- and tissue-based interaction systems necessary for the establishment of a functional, multicellular body. However, a network of neurons, one cell/tissue-communication system is missing in sponges. This fact is puzzling and enigmatic, because these animals possess receptors known to be involved in the nervous system in evolutionary younger animal phyla. As an example, the metabotropic glutamate/GABA-like receptor has been identified and cloned by us. Recently, we have identified a novel light transmi…
The C-terminal domain of ParB is critical for dynamic DNA binding and bridging interactions which condense the bacterial centromere
2017
SUMMARYThe ParB protein forms DNA bridging interactions aroundparSto form networks which condense DNA and earmark the bacterial chromosome for segregation. The mechanism underlying the formation of ParB nucleoprotein complexes is unclear. We show here that the central DNA binding domain is essential for anchoring atparS, and that this interaction is not required for DNA condensation. Structural analysis of the C-terminal domain reveals a dimer with a lysine-rich surface that binds DNA non-specifically and is essential for DNA condensationin vitro. Mutation of either the dimerisation or the DNA binding interface eliminates ParB foci formationin vivo. Moreover, the free C-terminal domain can …
Sensory exploration of the freshness sensation in plain yoghurts and yoghurt-like products
2013
WOS: 000324008600021 ; http://www.sciencedirect.com/science/article/pii/S0950329313001092; International audience; The term "freshness sensation" is used by consumers for characterizing some plain yoghurts and yoghurt-like products. This study consisted in an investigation of this sensation aiming at determining its underlying sensory attributes. First, two focus groups of consumers were conducted to open up the framework. A set of plain yoghurts and yoghurt-like products, both commercial and experimental, was then subjected to sensory analysis. The samples were sorted by means of a free sorting task, and further scored for the intensity of their freshness sensation and their liking, by 72 …
Vanillin cell sensor
2007
Our project for iGEM 2006 consisted of designing a cellular vanillin biosensor. We used an EnvZ -E. coli strain as a chassis, and constructed two different devices: a sensor and an actuator, assembled using OmpR-P as a standardised mediator. The sensor device contained a computation- ally designed vanillin receptor and a synthetic two-component signal transduction protein (Trz). The receptor protein was based on a ribose-binding protein as scaffold. The Trz was built by fusion of the periplasmic and transmembrane domains of a Trg protein with an EnvZ kinase domain. When the receptor complex binds Trg, an allosteric motion is propagated to the cyto- plasmic EnvZ kinase domain, resulting in a…
Silicateins, silicatein interactors and cellular interplay in sponge skeletogenesis: formation of glass fiber-like spicules
2012
Biomineralization processes are characterized by controlled deposition of inorganic polymers/minerals mediated by functional groups linked to organic templates. One metazoan taxon, the siliceous sponges, has utilized these principles and even gained the ability to form these polymers/minerals by an enzymatic mechanism using silicateins. Silicateins are the dominant protein species present in the axial canal of the skeletal elements of the siliceous sponges, the spicules, where they form the axial filament. Silicateins also represent a major part of the organic components of the silica lamellae, which are cylindrically arranged around the axial canal. With the demosponge Suberites domuncula …
Antibacterial activity of the sponge Suberites domuncula and its primmorphs: potential basis for epibacterial chemical defense
2003
The epibacterial chemical defense of the marine sponge Suberites domuncula was explored by screening sponge extract, sponge primmorph (3-D aggregates containing proliferating cells) extract and sponge-associated as well as primmorph-associated bacteria for antibacterial activ- ity. 16S rDNA sequencing revealed that the antimicrobially active bacteria belonged to the α - and γ- subdivisions of Proteobacteria (α -Proteobacterium MBIC 3368, Idiomarina sp. and Pseudomonas sp., respectively). Moreover, a recombinant perforin-like protein was cloned from S. domuncula that dis- played strong antibacterial activity. Based on these observations, it is proposed that the sponge may be provided with a …
Salt and Aroma Compound Distributions Influence Flavour Release and Temporal Perception While Eating Hot-Served Flans.
2021
International audience; To counteract the negative effect of salt overconsumption on health, strategies have been developed to reduce the salt content in food products. Among them, two promising strategies based on odour-induced saltiness enhancement and the heterogeneous distribution of flavour compounds were combined and assessed in four-layer cream-based snacks. To investigate the relationship between saltiness enhancement, temporal release and perception of flavour compounds in hot snacks with heterogeneous distribution of salt and aroma compounds, complementary techniques were used: nose space PTR-Tof-MS (Proton Transfer Reaction-Time of Flight–Mass Spectrometry) to assess the release …
Invisibilization and Silencing as an Ethical and Sociological Challenge
2017
AbstractExcluded and/or marginalized social groups frequently face problems involving representation in the public sphere. Moreover, the very notion of exclusion typically refers to communicatively or discursively produced mechanisms of being considered irrelevant in public processes of communication. Exclusion and marginalization, understood as processes of silencing or invisibilizing social groups, are particularly serious in cases involving social suffering, i.e. socially produced suffering and/or suffering that can be eliminated or alleviated socially. Making silence heard, giving voice to the silenced and bringing the invisibilized back into the public domain are therefore fundamental …