Time-resolved fluorescence imaging reveals differential interactions of N-glycan processing enzymes across the Golgi stack in planta

N-glycan processing is one of the most important cellular protein modifications in plants and as such is essential for plant development and defense mechanisms. The accuracy of Golgi-located processing steps is governed by the strict intra-Golgi localization of sequentially acting glycosidases and glycosyltransferases. Their differential distribution goes hand in hand with the compartmentalization of the Golgi stack into cis-, medial and trans-cisternae, which separate early from late processing steps. The mechanisms that direct differential enzyme concentration are still unknown, but formation of multi-enzyme complexes is considered a feasible Golgi protein localization strategy. In this study we used two-photon (2P)-excitation Förster resonance energy transfer (FRET)-fluorescence lifetime imaging microscopy (FLIM) to determine the interaction of N-glycan processing enzymes with differential intra-Golgi locations. Following the coexpression of fluorescent protein-tagged N-terminal Golgi targeting sequences (cytoplasmic-transmembrane-stem region, designated CTS) of enzyme pairs in leaves of tobacco (Nicotiana tabacum or Nicotiana benthamiana), we observed that all tested cis- and medial-Golgi enzymes, namely MNS1, GnTI, GMII and XylT, form homo- and heterodimers, whereas among the late-acting enzymes GALT1, FUT13 and ST (a non-plant Golgi marker) only GALT1 and GMII were found to form a heterodimer. Furthermore, the efficiency of energy transfer indicating the formation of interactions decreased considerably in a cis-to-trans fashion. The comparative 2P-FRET-FLIM analysis of several full-length cis- and medial-Golgi enzymes and their respective catalytic domain-deleted CTS clones further suggested that the formation of protein-protein interactions can occur through their N-terminal CTS region

Химические элементы в воде объектов водопользования бывшего Семипалатинского испытательного полигона как фактор экологического воздействия

Изучен элементный состав вод объектов водопользования расположенных на территории бывшего Семипалатинского испытательного полигона. Содержание U, Mo и Sr в изученных водах имеют превышения над средним составом подземных вод зон гипергенеза и континентального засоления. Выделены химические показатели и элементы превышающие ПДК это минерализация, общая жесткость, сульфаты, натрий и уран.The elemental composition of the water of odjects of water use in the territory of the former Semey test site was studied. The content of U, Mo and Sr in the studied waters has an excess over the average composition of groundwater in the areas of hypergenesis and continental salinization. Chemical indices and elements above MPC are identified as mineralization, total hardness, sulfates, sodium and uranium

Economic prospects of helium industry development in Russia

In this article authors examine the global and local Russian helium market and future helium trade trends; perform the analysis of helium industry development in East Siberia, its prospects and benefits, possible consumers of Russian helium; make several suggestions on its economic stimulation. The amounts of helium deposits in leading producing countries, geographical location of Russian helium resource base, technological problems on storage and transportation are also reviewed. As East Siberian gas fields are rich in helium and located near Asia-Pacific region - the main consumers of this high-technological associated gas - the problem of helium industry becomes topical. Moreover, annual losses of this rеsourсе will grow rapidly from East Siberia - Расifiс Oсеаn рiреlinе systеm is сommissionеd, so the quick protective actions are strongly required

The transmembrane domain of N-acetylglucosaminyltransferase I is the key determinant for its Golgi subcompartmentation

Golgi-resident type–II membrane proteins are asymmetrically distributed across the Golgi stack. The intrinsic features of the protein that determine its subcompartment-specific concentration are still largely unknown. Here, we used a series of chimeric proteins to investigate the contribution of the cytoplasmic, transmembrane and stem region of Nicotiana benthamiana N–acetylglucosaminyltransferase I (GnTI) for its cis/medial-Golgi localization and for protein–protein interaction in the Golgi. The individual GnTI protein domains were replaced with those from the well-known trans-Golgi enzyme α2,6–sialyltransferase (ST) and transiently expressed in Nicotiana benthamiana. Using co-localization analysis and N–glycan profiling, we show that the transmembrane domain of GnTI is the major determinant for its cis/medial-Golgi localization. By contrast, the stem region of GnTI contributes predominately to homomeric and heteromeric protein complex formation. Importantly, in transgenic Arabidopsis thaliana, a chimeric GnTI variant with altered sub-Golgi localization was not able to complement the GnTI-dependent glycosylation defect. Our results suggest that sequence-specific features in the transmembrane domain of GnTI account for its steady-state distribution in the cis/medial-Golgi in plants, which is a prerequisite for efficient N–glycan processing in vivo

Unraveling the function of Arabidopsis thaliana OS9 in the endoplasmic reticulum-associated degradation of glycoproteins

In the endoplasmic reticulum, immature polypeptides coincide with terminally misfolded proteins. Consequently, cells need a well-balanced quality control system, which decides about the fate of individual proteins and maintains protein homeostasis. Misfolded and unassembled proteins are sent for destruction via the endoplasmic reticulum-associated degradation (ERAD) machinery to prevent the accumulation of potentially toxic protein aggregates. Here, we report the identification of Arabidopsis thaliana OS9 as a component of the plant ERAD pathway. OS9 is an ER-resident glycoprotein containing a mannose-6-phosphate receptor homology domain, which is also found in yeast and mammalian lectins involved in ERAD. OS9 fused to the C-terminal domain of YOS9 can complement the ERAD defect of the corresponding yeast Δyos9 mutant. An A. thaliana OS9 loss-of-function line suppresses the severe growth phenotype of the bri1-5 and bri1-9 mutant plants, which harbour mutated forms of the brassinosteroid receptor BRI1. Co-immunoprecipitation studies demonstrated that OS9 associates with Arabidopsis SEL1L/HRD3, which is part of the plant ERAD complex and with the ERAD substrates BRI1-5 and BRI1-9, but only the binding to BRI1-5 occurs in a glycan-dependent way. OS9-deficiency results in activation of the unfolded protein response and reduces salt tolerance, highlighting the role of OS9 during ER stress. We propose that OS9 is a component of the plant ERAD machinery and may act specifically in the glycoprotein degradation pathway

Interprofessional Consensus Regarding Design Requirements for Liquid-Based Perinatal Life Support (PLS) Technology

Liquid-based perinatal life support (PLS) technology will probably be applied in a first-in-human study within the next decade. Research and development of PLS technology should not only address technical issues, but also consider socio-ethical and legal aspects, its application area, and the corresponding design implications. This paper represents the consensus opinion of a group of healthcare professionals, designers, ethicists, researchers and patient representatives, who have expertise in tertiary obstetric and neonatal care, bio-ethics, experimental perinatal animal models for physiologic research, biomedical modeling, monitoring, and design. The aim of this paper is to provide a framework for research and development of PLS technology. These requirements are considering the possible respective user perspectives, with the aim to co-create a PLS system that facilitates physiological growth and development for extremely preterm born infants

Early inhaled budesonide for the prevention of bronchopulmonary dysplasia

BACKGROUND Systemic glucocorticoids reduce the incidence of bronchopulmonary dysplasia among extremely preterm infants, but they may compromise brain development. The effects of inhaled glucocorticoids on outcomes in these infants are unclear. METHODS We randomly assigned 863 infants (gestational age, 23 weeks 0 days to 27 weeks 6 days) to early (within 24 hours after birth) inhaled budesonide or placebo until they no longer required oxygen and positive-pressure support or until they reached a postmenstrual age of 32 weeks 0 days. The primary outcome was death or bronchopulmonary dysplasia, confirmed by means of standardized oxygen-saturation monitoring, at a postmenstrual age of 36 weeks. RESULTS A total of 175 of 437 infants assigned to budesonide for whom adequate data were available (40.0%), as compared with 194 of 419 infants assigned to placebo for whom adequate data were available (46.3%), died or had bronchopulmonary dysplasia (relative risk, stratified according to gestational age, 0.86; 95% confidence interval [CI], 0.75 to 1.00; P = 0.05). The incidence of bronchopulmonary dysplasia was 27.8% in the budesonide group versus 38.0% in the placebo group (relative risk, stratified according to gestational age, 0.74; 95% CI, 0.60 to 0.91; P = 0.004); death occurred in 16.9% and 13.6% of the patients, respectively (relative risk, stratified according to gestational age, 1.24; 95% CI, 0.91 to 1.69; P = 0.17). The proportion of infants who required surgical closure of a patent ductus arteriosus was lower in the budesonide group than in the placebo group (relative risk, stratified according to gestational age, 0.55; 95% CI, 0.36 to 0.83; P = 0.004), as was the proportion of infants who required reintubation (relative risk, stratified according to gestational age, 0.58; 95% CI, 0.35 to 0.96; P = 0.03). Rates of other neonatal illnesses and adverse events were similar in the two groups. CONCLUSIONS Among extremely preterm infants, the incidence of bronchopulmonary dysplasia was lower among those who received early inhaled budesonide than among those who received placebo, but the advantage may have been gained at the expense of increased mortality