Lack of evidence for direct phosphorylation of recombinantly expressed P2X2 and P2X3 receptors by protein kinase C

P2X3 and P2X2+3 receptors are present on sensory neurons, where they contribute not only to transient nociceptive responses, but also to hypersensitivity underlying pathological pain states elicited by nerve injuries. Increased signalling through P2X3 and P2X2+3 receptors may arise from an increased routing to the plasma membrane and/or gain of function of pre-existing receptors. An obvious effector mechanism for functional modulation is protein kinase C (PKC)-mediated phosphorylation, since all P2X family members share a conserved consensus sequence for PKC, TXR/K, within the intracellularly located N-terminal domain. Contradictory reports have been published regarding the exact role of this motif. In the present study, we confirm that site-directed elimination of the potential phosphor-acceptor threonine or the basic residue in the P+2 position of the TXR/K sequence accelerates desensitization of P2X2 receptors and abolishes P2X3 receptor function. Moreover, the PKC activator phorbol 12-myristate 13-acetate increased P2X3 (but not P2X2) receptor-mediated currents. Biochemically, however, we were unable to demonstrate by various experimental approaches a direct phosphorylation of wild-type P2X2 and P2X3 receptors expressed in both Xenopus laevis oocytes and HEK293 cells. In conclusion, our data support the view that the TXR/K motif plays an important role in P2X function and that phorbol 12-myristate 13-acetate is capable of modulating some P2X receptor subtypes. The underlying mechanism, however, is unlikely to involve direct PKC-mediated P2X receptor phosphorylation

The Nitrogen Content in the Fruiting Body and Mycelium of Pleurotus Ostreatus and Its Utilization as a Medium Component in Thraustochytrid Fermentation

Following the idea of a circular bioeconomy, the use of side streams as substitutes for cultivation media (components) in bioprocesses would mean an enormous economic and ecological advantage. Costly compounds in conventional media for the production of the triterpene squalene in thraustochytrids are the main carbon source and complex nitrogen sources. Among other side streams examined, extracts from the spent mycelium of the basidiomycete Pleurotus ostreatus were best-suited to acting as alternative nitrogen sources in cultivation media for thraustochytrids. The total nitrogen (3.76 ± 0.01 and 4.24 ± 0.04%, respectively) and protein (16.47 ± 0.06 and 18.57 ± 0.18%, respectively) contents of the fruiting body and mycelium were determined. The fungal cells were hydrolyzed and extracted to generate accessible nitrogen sources. Under preferred conditions, the extracts from the fruiting body and mycelium contained 73.63 ± 1.19 and 89.93 ± 7.54 mM of free amino groups, respectively. Cultivations of Schizochytrium sp. S31 on a medium using a mycelium extract as a complex nitrogen source showed decelerated growth but a similar squalene yield (123.79 ± 14.11 mg/L after 216 h) compared to a conventional medium (111.29 ± 19.96 mg/L, although improvable by additional complex nitrogen source)

Проектирование комплекса геофизических исследований скважин для определения коллекторских свойств на Яунлорском месторождении (ХМАО-Югра)

Объектом исследования является проектная скважина №7200 глубиной 3100 м со вскрытием юрских отложений – пласты ЮС1, ЮС2, ЮС3. Скважина заложена в пределах Яунлорского куполовидного поднятия. Цель работы: проектирование комплекса геофизических исследований в открытом стволе скважины №1400 для оценки коллекторских свойств пластов-коллекторов в среднеюрском нефтегазоносном комплексе на Яунлорском месторождении.The object of the study is project well No. 7200 with a depth of 3100 m with the discovery of Jurassic deposits - formations J1, J2, J3. The well is within the domed uplift of Jaunlor. Purpose of work: designing a complex of geophysical surveys in an open well of well No. 1400 for assessing the reservoir properties of the formation in the middle Jurassic of the oil and gas complex at the Yaunlor field

Structural basis for m7G-cap hypermethylation of small nuclear, small nucleolar and telomerase RNA by the dimethyltransferase TGS1

The 5′-cap of spliceosomal small nuclear RNAs, some small nucleolar RNAs and of telomerase RNA was found to be hypermethylated in vivo. The Trimethylguanosine Synthase 1 (TGS1) mediates this conversion of the 7-methylguanosine-cap to the 2,2,7-trimethylguanosine (m3G)-cap during maturation of the RNPs. For mammalian UsnRNAs the generated m2,2,7G-cap is one part of a bipartite import signal mediating the transport of the UsnRNP-core complex into the nucleus. In order to understand the structural organization of human TGS1 as well as substrate binding and recognition we solved the crystal structure of the active TGS1 methyltransferase domain containing both, the minimal substrate m7GTP and the reaction product S-adenosyl-l-homocysteine (AdoHcy). The methyltransferase of human TGS1 harbors the canonical class 1 methyltransferase fold as well as an unique N-terminal, α-helical domain of 40 amino acids, which is essential for m7G-cap binding and catalysis. The crystal structure of the substrate bound methyltransferase domain as well as mutagenesis studies provide insight into the catalytic mechanism of TGS1

Klimawandel und Teichwirtschaft: Auswirkungen des Klimawandels auf die Perspektiven in der sächsischen Teichwirtschaft

Die Veröffentlichung enthält differenzierte Analysen für die Entwicklung von Temperatur, Niederschlag und Sonnenscheindauer sowie deren Schwankungen für die sieben Gebiete in Sachsen, in denen sich die meisten Karpfenteichwirtschaften befinden. Dabei werden sowohl die Vergangenheit als auch die mögliche zukünftige Klimaentwicklung betrachtet. Die Broschüre richtet sich an Teichwirte, Fach- und Förderverwaltungen, Planer, Naturschutz-, Heimatschutz- und Tourismusverbände sowie die interessierte Öffentlichkeit

Role of the podocyte in proteinuria

In recent years, the podocyte, with its elaborate cytoarchitecture and slit diaphragm, has been the focus of extensive research, yet its precise role in the glomerular filtration barrier is still debated. There are puzzling observations indicating that a comprehensive mechanistic model for glomerular filtration is still necessary. There is no doubt that podocytes are essential for glomerular filtration barrier integrity. However, most albumin never reaches the podocyte because it is prevented from entering the glomerular filter at the endothelium level. Another puzzling observation is that the glomerular filter never clogs despite its high load of several kilograms of plasma proteins per day. Recently, we proposed a novel model in which an electrical potential difference is generated across the glomerular filtration barrier by filtration. The model offers novel potential solutions to some of the riddles regarding the glomerular filter