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231.
The origin and evolution of novel biochemical functions remains one of the key questions in molecular evolution. We study recently emerged methacrylate reductase function that is thought to have emerged in the last century and reported in Geobacter sulfurreducens strain AM-1. We report the sequence and study the evolution of the operon coding for the flavin-containing methacrylate reductase (Mrd) and tetraheme cytochrome с (Mcc) in the genome of G. sulfurreducens AM-1. Different types of signal peptides in functionally interlinked proteins Mrd and Mcc suggest a possible complex mechanism of biogenesis for chromoproteids of the methacrylate redox system. The homologs of the Mrd and Mcc sequence found in δ-Proteobacteria and Deferribacteres are also organized into an operon and their phylogenetic distribution suggested that these two genes tend to be horizontally transferred together. Specifically, the mrd and mcc genes from G. sulfurreducens AM-1 are not monophyletic with any of the homologs found in other Geobacter genomes. The acquisition of methacrylate reductase function by G. sulfurreducens AM-1 appears linked to a horizontal gene transfer event. However, the new function of the products of mrd and mcc may have evolved either prior or subsequent to their acquisition by G. sulfurreducens AM-1.  相似文献   
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233.
An effective procedure for the synthesis of ribonucleotide monomers containing a 2 ′-О-methoxymethyl-modifying group was developed. These monomers were used for the synthesis of RNA fragments by the solid-phase phosphotriester method under O-nucleophilic intramolecular catalysis. The properties of 2 ′-О-methoxymethyl-containing oligoribonucleotides were examined.  相似文献   
234.
1. New information identifying nucleotide alterations of human butyrylcholinesterase allows the use of more specific nomenclature for the variants commonly known as atypical, fluoride, silent, and K variant. 2. In addition to suggesting a system of trivial names and abbreviations, we provide a list of formal names that follow the guidelines of the Committee for Human Gene Nomenclature. 3. It is suggested that formal names be included in publications whenever possible.  相似文献   
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236.
This interdisciplinary study applies a series of environmental tests developed in Fennoscandia to elaborate the patterns created by contemporary and past reindeer husbandry along the Zhuia River, Bodaibo district, Irkutsk oblast’, Russian Federation. We successfully used pollen and fungal spore analysis to document the long-term use of one site by ungulates–although it remains unclear if these animals were ‘domestic’ reindeer or not. The date of occupation could go as far back as the fourteenth century. The on-site phosphate analysis, attempted for the first time in Eastern Siberia, proved a useful tool for locating the sites of animal action although failed to specify the boundaries of that action. It did emphasise the importance of accounting for the agency of wind in ordering reindeer behaviour. Finally, the combined phosphate, botanical, and pollen work documented a history of succession of types of land-use from the hunting of Rangifer, to holding Rangifer, to the maintenance of meadows for horses or cattle, to the formation of cereal crops and vegetable patches. The combined use of these methods and a discussion of the ambiguities they produced suggests that they are best employed to find distinctive sites in the landscape which attract both people and animals and are less effective in documenting a Euro-American vision of trust or domination in human-animal relations.  相似文献   
237.

Background

Effect of chlorocholine chloride (CCC) on phenolic acids composition and polyphenols accumulation in various anatomical parts (stems, leaves and inflorescences) of common buckwheat (Fagopyrum esculentum Moench) in the early stages of vegetation period were surveyed.

Results

Treatment of buckwheat seeds with 2% of CCC has been increased content of total phenolics in the stems, leaves and inflorescences. On analyzing the different parts of buckwheat plants, 9 different phenolic acids – vanilic acid, ferulic acid, trans-ferulic acid, chlorogenic acid, salycilic acid, cinamic acid, p-coumaric acid, p-anisic acid, methoxycinamic acid and catechins were identified. The levels of identified phenolic acids varied not only significantly among the plant organs but also between early stages of vegetation period. Same changes as in contents of chlorogenic acid, ferulic acid, trans-ferulic acid were found for content of salycilic acid. The content of these phenolic acids has been significant increased under effect of 2% CCC treatment at the phase I (formation of buds) in the stems and at the phase II (beginning of flowering) in the leaves and then inflorescences respectively. The content of catechins as potential buckwheat antioxidants has been increased at the early stages of vegetation period after treatment with 2% CCC.

Conclusions

The obtained results suggest that influence of CCC on the phenolics composition can be a result of various mechanisms of CCC uptake, transforming and/or its translocation in the buckwheat seedlings.  相似文献   
238.

Introduction

Syndecans are heparan sulphate proteoglycans expressed by endothelial cells. Syndecan-3 is expressed by synovial endothelial cells of rheumatoid arthritis (RA) patients where it binds chemokines, suggesting a role in leukocyte trafficking. The objective of the current study was to examine the function of syndecan-3 in joint inflammation by genetic deletion in mice and compare with other tissues.

Methods

Chemokine C-X-C ligand 1 (CXCL1) was injected in the joints of syndecan-3−/−and wild-type mice and antigen-induced arthritis performed. For comparison chemokine was administered in the skin and cremaster muscle. Intravital microscopy was performed in the cremaster muscle.

Results

Administration of CXCL1 in knee joints of syndecan-3−/−mice resulted in reduced neutrophil accumulation compared to wild type. This was associated with diminished presence of CXCL1 at the luminal surface of synovial endothelial cells where this chemokine clustered and bound to heparan sulphate. Furthermore, in the arthritis model syndecan-3 deletion led to reduced joint swelling, leukocyte accumulation, cartilage degradation and overall disease severity. Conversely, CXCL1 administration in the skin of syndecan-3 null mice provoked increased neutrophil recruitment and was associated with elevated luminal expression of E-selectin by dermal endothelial cells. Similarly in the cremaster, intravital microscopy showed increased numbers of leukocytes adhering and rolling in venules in syndecan-3−/−mice in response to CXCL1 or tumour necrosis factor alpha.

Conclusions

This study shows a novel role for syndecan-3 in inflammation. In the joint it is selectively pro-inflammatory, functioning in endothelial chemokine presentation and leukocyte recruitment and cartilage damage in an RA model. Conversely, in skin and cremaster it is anti-inflammatory.  相似文献   
239.
Construction of a mitotic spindle requires biochemical pathways to assemble spindle microtubules and structural proteins to organize these microtubules into a bipolar array. Through a complex with dynein, the receptor for hyaluronan-mediated motility (RHAMM) cross-links mitotic microtubules to provide structural support, maintain spindle integrity, and correctly orient the mitotic spindle. Here, we locate RHAMM to sites of microtubule assembly at centrosomes and non-centrosome sites near kinetochores and demonstrate that RHAMM is required for the activation of Aurora kinase A. Silencing of RHAMM delays the kinetics of spindle assembly, mislocalizes targeting protein for XKlp2 (TPX2), and attenuates the localized activation of Aurora kinase A with a consequent reduction in mitotic spindle length. The RHAMM–TPX2 complex requires a C-terminal basic leucine zipper in RHAMM and a domain that includes the nuclear localization signal in TPX2. Together, our findings identify RHAMM as a critical regulator for Aurora kinase A signaling and suggest that RHAMM ensures bipolar spindle assembly and mitotic progression through the integration of biochemical and structural pathways.  相似文献   
240.
Adipose tissue secretes a variety of bioactive factors, which can regulate cardiomyocyte hypertrophy via reactive oxygen species (ROS). In the present study we investigated whether apelin affects ROS-dependent cardiac hypertrophy. In cardiomyocytes apelin inhibited the hypertrophic response to 5-HT and oxidative stress induced by 5-HT- or H2O2 in a dose-dependent manner. These effects were concomitant to the increase in mRNA expression and activity of catalase. Chronic treatment of mice with apelin attenuated pressure-overload-induced left ventricular hypertrophy. The prevention of hypertrophy by apelin was associated with increased myocardial catalase activity and decreased plasma lipid hydroperoxide, as an index of oxidative stress. These results show that apelin behaves as a catalase activator and prevents cardiac ROS-dependent hypertrophy.  相似文献   
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