Detection of Transglutaminase 2 conformational changes in living cell

Transglutaminase 2 (TG2) is a ubiquitous Ca(2+)-dependent protein cross-linking enzyme that is implicated in a variety of biological disorders. In in vitro experiments when Ca(2+) concentration was increased TG2 changed its conformation and was able to cross-link other proteins via formation of an isopeptide bond. However the mechanisms that regulate TG2 transamidation activity in cells are still unknown. In this study we have developed FRET-based method for monitoring TG2 conformation changes and, probably, cross-linking activity in living cells. Using this approach we have showed that a significant amount of TG2 within the cell is accumulated in perinuclear endosomes and has a cross-linking inactive conformation, while TG2 that is located beneath the cell membrane has a transamidation active conformation. After the induction of apoptosis cytoplasmic TG2 changed its conformation and activates while, TG2 in endosomes retained transamidation inactive conformation even at late stages of apoptosis.     

The influence of medium composition on alkaloid biosynthesis by Penicillium citrinum

The fungus P. citrinum produces secondary metabolites, clavine ergot alkaloids (EA), and quinoline alkaloids quinocitrinines (QA) in medium with various carbon and nitrogen sources and in the presence of iron, copper, and zinc additives. Mannitol and sucrose are most favorable for EA biosynthesis and mannitol is most favorable for QA. Maximum alkaloid production is observed on urea. Iron and copper additives in the medium containing zinc ions stimulated fungal growth but inhibited alkaloid biosynthesis. The production of these secondary metabolites does not depend on the physiological state of culture, probably due to the constitutive nature of the enzymes involved in biosynthesis of these substances.     

Photoregulation of Protochlorophyllide Oxidoreductase and Rubisco Large Subunit Accumulation in Phytochrome A-Deficient Transgenic Tobacco Plants

Some morphogenetic responses, induced by far red (FR) light in tobacco plants (Nicotiana tabacum L.), were studied. The inhibitory effect of FR irradiation on chlorophyll synthesis in transgenic plants with reduced phytochrome A content was almost absent. Phytochrome A-mediated repression of the por gene was demonstrated with the use of polyclonal antiserum against protochlorophyllide oxidoreductase. Continuous FR light induced the accumulation of Rubisco large subunits in wild-type but not in transgenic tobacco plants. Our data confirm the suggestion that phytochrome A mediates photoregulation of the synthesis of these proteins.     

土壤中棉花黄萎病菌SYBR Green Ⅰ荧光RT-PCR定量检测技术研究

为实现田间土壤棉花黄萎病菌的早期检测,建立了土壤中棉花黄萎病菌的SYBR GreenⅠ荧光定量PCR检测方法.以含342bp PCR扩增产物的阳性质粒为参考,构建了标准曲线,并对该曲线的特异性、敏感性、可重复性进行了评价.结果表明,该方法具有快速、特异性强、敏感度高等特点.检测范围在3.8×103-3.8×108cop...     

RedeR: R/Bioconductor package for representing modular structures, nested networks and multiple levels of hierarchical associations

Visualization and analysis of molecular networks are both central to systems biology. However, there still exists a large technological gap between them, especially when assessing multiple network levels or hierarchies. Here we present RedeR, an R/Bioconductor package combined with a Java core engine for representing modular networks. The functionality of RedeR is demonstrated in two different scenarios: hierarchical and modular organization in gene co-expression networks and nested structures in time-course gene expression subnetworks. Our results demonstrate RedeR as a new framework to deal with the multiple network levels that are inherent to complex biological systems. RedeR is available from http://bioconductor.org/packages/release/bioc/html/RedeR.html.     

The Effect of the Composition of a Liposomal Nanocomplex on the Antioxidant Activity of Murine Blood Plasma and Lipids of the Liver and Brain

Much attention is given to research and development of efficient systems for the delivery of essential omega-3-polyunsaturated fatty acids and other nutraceuticals to the human body with food. Nanocomplexes, which are based on soybean phosphatidylcholine liposomes with nutraceuticals included, are among the efficient delivery systems. The prolonged use of these nanocomplexes may affect the antioxidant status in various organs and tissues. In this work, thermo-initiated chemiluminescence was used to study changes in the antioxidant activity of the blood plasma, liver, and brain lipids in mice divided into six groups depending on the composition of liposomal nanocomplexes introduced into drinks substituted for water in a long-term (3 month) diet. The components of six types of liposomal nanocomplexes, except for phosphatidylcholine, in different combinations were clove essential oil, fish oil, and sodium caseinate. The results of the study showed that nanocomplexes containing liposomes made of phosphatidylcholine with the addition of fish oil and clove essential oil and encapsulated in milk protein (sodium caseinate) proved to be the most effective in increasing the antioxidant activity of the blood plasma and brain lipids in mice compared to the control.

     

Characteristics of the immunological reactivity of the body in the streptococcal carrier state

The use of the discrete dynamic method for the treatment of data obtained in the survey of streptococcus carriers has made it possible to find out that their immune status is determined not so much by the quantitative changes in the results of individual immunological tests (for the bactericidal activity of the blood serum, lysozyme, IgG, IgM, IgA and the phagocytic activity of neutrophils), but, to a greater extent, by the interrelations of these characteristics. Significant differences in the interrelations of various humoral characteristics and in their relationship to the phagocytic process have been detected in the group of carriers as compared with the control group.     

Candidate cell and matrix interaction domains on the collagen fibril, the predominant protein of vertebrates

Type I collagen, the predominant protein of vertebrates, polymerizes with type III and V collagens and non-collagenous molecules into large cable-like fibrils, yet how the fibril interacts with cells and other binding partners remains poorly understood. To help reveal insights into the collagen structure-function relationship, a data base was assembled including hundreds of type I collagen ligand binding sites and mutations on a two-dimensional model of the fibril. Visual examination of the distribution of functional sites, and statistical analysis of mutation distributions on the fibril suggest it is organized into two domains. The "cell interaction domain" is proposed to regulate dynamic aspects of collagen biology, including integrin-mediated cell interactions and fibril remodeling. The "matrix interaction domain" may assume a structural role, mediating collagen cross-linking, proteoglycan interactions, and tissue mineralization. Molecular modeling was used to superimpose the positions of functional sites and mutations from the two-dimensional fibril map onto a three-dimensional x-ray diffraction structure of the collagen microfibril in situ, indicating the existence of domains in the native fibril. Sequence searches revealed that major fibril domain elements are conserved in type I collagens through evolution and in the type II/XI collagen fibril predominant in cartilage. Moreover, the fibril domain model provides potential insights into the genotype-phenotype relationship for several classes of human connective tissue diseases, mechanisms of integrin clustering by fibrils, the polarity of fibril assembly, heterotypic fibril function, and connective tissue pathology in diabetes and aging.     

Nitrogen in global animal production and management options for improving nitrogen use efficiency

Animal production systems convert plant protein into animal protein. Depending on animal species, ration and management, between 5% and 45 % of the nitrogen (N) in plant protein is converted to and deposited in animal protein. The other 55%-95% is excreted via urine and feces, and can be used as nutrient source for plant (= often animal feed) production. The estimated global amount of N voided by animals ranges between 80 and 130 Tg N per year, and is as large as or larger than the global annual N fertilizer consumption. Cattle (60%), sheep (12%) and pigs (6%) have the largest share in animal manure N production. The conversion of plant N into animal N is on average more efficient in poultry and pork production than in dairy production, which is higher than in beef and sheep production. However, differences within a type of animal production system can be as large as differences between types of animal production systems, due to large effects of the genetic potential of animals, animal feed and management. The management of animals and animal feed, together with the genetic potential of the animals, are key factors to a high efficiency of conversion of plant protein into animal protein. The efficiency of the conversion of N from animal manure, following application to land, into plant protein ranges between 0 and 60%, while the estimated global mean is about 15%. The other 40%-100% is lost to the wider environment via NH3 volatilization, denitrification, leaching and run-off in pastures or during storage and/or following application of the animal manure to land. On a global scale, only 40%-50% of the amount of N voided is collected in barns, stables and paddocks, and only half of this amount is recycled to crop land. The N losses from animal manure collected in barns, stables and paddocks depend on the animal manure management system. Relative large losses occur in confined animal feeding operations, as these often lack the land base to utilize the N from animal manure effectively. Losses will be relatively low when all manure are collected rapidly in water-tight and covered basins, and when they are subsequently applied to the land in proper amounts and at the proper time, and using the proper method (low-emission techniques). There is opportunity for improving the N conversion in animal production systems by improving the genetic production potential of the herd, the composition of the animal feed, and the management of the animal manure. Coupling of crop and animal production systems, at least at a regional scale, is one way to high N use efficiency in the whole system. Clustering of confined animal production systems with other intensive agricultural production systems on the basis of concepts from industrial ecology with manure processing is another possible way to improve N use efficiency.