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排序方式: 共有71条查询结果,搜索用时 15 毫秒
1.
Sergio Porté Agrin Moeini Irene Reche Naeem Shafqat Udo Oppermann Jaume Farrés Xavier Parés 《Cellular and molecular life sciences : CMLS》2011,68(6):1065-1077
Human ζ-crystallin is a Zn2+-lacking medium-chain dehydrogenase/reductase (MDR) included in the quinone oxidoreductase (QOR) family because of its activity
with quinones. In the present work a novel enzymatic activity was characterized: the double bond α,β-hydrogenation of medium-chain
2-alkenals and 3-alkenones. The enzyme is especially active with lipid peroxidation products such as 4-hydroxyhexenal, and
a role in their detoxification is discussed. This specificity is novel in the QOR family, and it is similar to that described
in the distantly related alkenal/one reductase family. Moreover, we report the X-ray structure of ζ-crystallin, which represents
the first structure solved for a tetrameric Zn2+-lacking MDR, and which allowed the identification of the active-site lining residues. Docking simulations suggest a role
for Tyr53 and Tyr59 in catalysis. The kinetics of Tyr53Phe and Tyr59Phe mutants support the implication of Tyr53 in binding/catalysis
of alkenal/one substrates, while Tyr59 is involved in the recognition of 4-OH-alkenals. 相似文献
2.
DNA methylation is the major epigenetic modification and it is involved in the negative regulation of gene expression. Its alteration can lead to neoplastic transformation. Several biomolecular approaches are nowadays used to study this modification on DNA, but also on RNA molecules, which are known to play a role in different biological processes. RNA methylation is one of the most common RNA modifications and 5-methylcytosine presence has recently been suggested in mRNA. However, an analysis of nucleic acid methylation at electron microscope is still lacking. Therefore, we visualized DNA methylation status and RNA methylation sites in the interphase nucleus of HeLa cells and rat hepatocytes by ultrastructural immunocytochemistry and cytochemical staining. This approach represents an efficient alternative to study nucleic acid methylation. In particular, this ultrastructural method makes the visualization of this epigenetic modification on a single RNA molecule possible, thus overcoming the technical limitations for a (pre-)mRNA methylation analysis. 相似文献
3.
4.
Juliana L. Segadilha Priscila S. Nascimento Fábio M. Mauro Cristiana S. Serejo Taiara R. Ramos Irene A. Cardoso 《Journal of Natural History》2018,52(1-2):1-11
A total of 3109 crustaceans belonging to 50 taxa distributed in 42 families were found in 117 analysed stomachs of flying gurnard (Dactylopterus volitans). Samples were obtained in April 2008 by the R/V Gyre using a bottom trawl towed in 12 stations at 14–100 m depth on the continental shelf of the Campos Basin, Brazil. The carcinofauna was analysed and the order Calanoida (Copepoda) found to be the most important item in terms of relative abundance and frequency of occurrence, followed by the order Amphipoda (Peracarida), the infraorder Brachyura (Decapoda), the order Stomatopoda and the subclass Myodocopa (Ostracoda). In the order Calanoida, the species Pontellopsis cf. villosa (Pontellidae) represented 98.04% of total crustacean abundance. The diet of Dactylopterus volitans varied according to fish size, with higher diversity of Crustacea at smaller size classes, decreasing in larger fishes. A similar pattern regarding depth was obtained, with greater diversity of taxa in gurnard stomachs caught at shallower depths. Flying gurnard is considered a generalized carnivore of invertebrates, eating mobile macrobenthic organisms, such as crustaceans, and its diet varies with its life stage, without any specific group as its main food source. 相似文献
5.
Becker-Heck A Zohn IE Okabe N Pollock A Lenhart KB Sullivan-Brown J McSheene J Loges NT Olbrich H Haeffner K Fliegauf M Horvath J Reinhardt R Nielsen KG Marthin JK Baktai G Anderson KV Geisler R Niswander L Omran H Burdine RD 《Nature genetics》2011,43(1):79-84
Primary ciliary dyskinesia (PCD) is a genetically heterogeneous autosomal recessive disorder characterized by recurrent infections of the respiratory tract associated with the abnormal function of motile cilia. Approximately half of individuals with PCD also have alterations in the left-right organization of their internal organ positioning, including situs inversus and situs ambiguous (Kartagener's syndrome). Here, we identify an uncharacterized coiled-coil domain containing a protein, CCDC40, essential for correct left-right patterning in mouse, zebrafish and human. In mouse and zebrafish, Ccdc40 is expressed in tissues that contain motile cilia, and mutations in Ccdc40 result in cilia with reduced ranges of motility. We further show that CCDC40 mutations in humans result in a variant of PCD characterized by misplacement of the central pair of microtubules and defective assembly of inner dynein arms and dynein regulatory complexes. CCDC40 localizes to motile cilia and the apical cytoplasm and is required for axonemal recruitment of CCDC39, disruption of which underlies a similar variant of PCD. 相似文献
6.
Evidence for cultivar adoption and emerging complexity during the mid-Holocene in the La Plata basin
Iriarte J Holst I Marozzi O Listopad C Alonso E Rinderknecht A Montaña J 《Nature》2004,432(7017):614-617
Multidisciplinary investigations at the Los Ajos archaeological mound complex in the wetlands of southeastern Uruguay challenge the traditional view that the La Plata basin was inhabited by simple groups of hunters and gatherers for much of the pre-Hispanic era. Here we report new archaeological, palaeoecological and botanical data indicating that during an increasingly drier mid-Holocene, at around 4,190 radiocarbon (14C) years before present (bp), Los Ajos became a permanent circular plaza village, and its inhabitants adopted the earliest cultivars known in southern South America. The architectural plan of Los Ajos during the following Ceramic Mound Period (around 3,000-500 14C yr bp) is similar to, but earlier than, settlement patterns demonstrated in Amazonia, revealing a new and independent architectural tradition for South America. 相似文献
7.
Vissers LE van Ravenswaaij CM Admiraal R Hurst JA de Vries BB Janssen IM van der Vliet WA Huys EH de Jong PJ Hamel BC Schoenmakers EF Brunner HG Veltman JA van Kessel AG 《Nature genetics》2004,36(9):955-957
CHARGE syndrome is a common cause of congenital anomalies affecting several tissues in a nonrandom fashion. We report a 2.3-Mb de novo overlapping microdeletion on chromosome 8q12 identified by array comparative genomic hybridization in two individuals with CHARGE syndrome. Sequence analysis of genes located in this region detected mutations in the gene CHD7 in 10 of 17 individuals with CHARGE syndrome without microdeletions, accounting for the disease in most affected individuals. 相似文献
8.
Germline mutations in FH predispose to dominantly inherited uterine fibroids, skin leiomyomata and papillary renal cell cancer 总被引:26,自引:0,他引:26
Tomlinson IP Alam NA Rowan AJ Barclay E Jaeger EE Kelsell D Leigh I Gorman P Lamlum H Rahman S Roylance RR Olpin S Bevan S Barker K Hearle N Houlston RS Kiuru M Lehtonen R Karhu A Vilkki S Laiho P Eklund C Vierimaa O Aittomäki K Hietala M Sistonen P Paetau A Salovaara R Herva R Launonen V Aaltonen LA;Multiple Leiomyoma Consortium 《Nature genetics》2002,30(4):406-410
9.
Segal E Fondufe-Mittendorf Y Chen L Thåström A Field Y Moore IK Wang JP Widom J 《Nature》2006,442(7104):772-778
10.
Raghoebarsing AA Smolders AJ Schmid MC Rijpstra WI Wolters-Arts M Derksen J Jetten MS Schouten S Sinninghe Damsté JS Lamers LP Roelofs JG Op den Camp HJ Strous M 《Nature》2005,436(7054):1153-1156
Wetlands are the largest natural source of atmospheric methane, the second most important greenhouse gas. Methane flux to the atmosphere depends strongly on the climate; however, by far the largest part of the methane formed in wetland ecosystems is recycled and does not reach the atmosphere. The biogeochemical controls on the efficient oxidation of methane are still poorly understood. Here we show that submerged Sphagnum mosses, the dominant plants in some of these habitats, consume methane through symbiosis with partly endophytic methanotrophic bacteria, leading to highly effective in situ methane recycling. Molecular probes revealed the presence of the bacteria in the hyaline cells of the plant and on stem leaves. Incubation with (13)C-methane showed rapid in situ oxidation by these bacteria to carbon dioxide, which was subsequently fixed by Sphagnum, as shown by incorporation of (13)C-methane into plant sterols. In this way, methane acts as a significant (10-15%) carbon source for Sphagnum. The symbiosis explains both the efficient recycling of methane and the high organic carbon burial in these wetland ecosystems. 相似文献