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排序方式: 共有481条查询结果,搜索用时 15 毫秒
51.
Identification of novel mutations of the human N-acetylglutamate synthase gene and their functional investigation by expression studies 总被引:1,自引:0,他引:1
Schmidt E Nuoffer JM Häberle J Pauli S Guffon N Vianey-Saban C Wermuth B Koch HG 《Biochimica et biophysica acta》2005,1740(1):54-59
The mitochondrial enzyme N-acetylglutamate synthase (NAGS) produces N-acetylglutamate serving as an allosteric activator of carbamylphosphate synthetase 1, the first enzyme of the urea cycle. Autosomal recessively inherited NAGS deficiency (NAGSD) leads to severe neonatal or late-onset hyperammonemia. To date few patients have been described and the gene involved was described only recently. In this study, another three families affected by NAGSD were analyzed for NAGS gene mutations resulting in the identification of three novel missense mutations (C200R [c.598T > C], S410P [c.1228T > C], A518T [c.1552G > A]). In order to investigate the effects of these three and two additional previously published missense mutations on enzyme activity, the mutated proteins were overexpressed in a bacterial expression system using the NAGS deficient E. coli strain NK5992. All mutated proteins showed a severe decrease in enzyme activity providing evidence for the disease-causing nature of the mutations. In addition, we expressed the full-length NAGS wild type protein including the mitochondrial leading sequence, the mature protein as well as a highly conserved core protein. NAGS activity was detected in all three recombinant proteins but varied regarding activity levels and response to stimulation by l-arginine. In conclusion, overexpression of wild type and mutated NAGS proteins in E. coli provides a suitable tool for functional analysis of NAGS deficiency. 相似文献
52.
Mustonen H Lepistö A Lehtonen S Lehtonen E Puolakkainen P Kivilaakso E 《Biochemical and biophysical research communications》2005,332(2):426-432
The potential association of CD2AP with the adherens junction protein E-cadherin, co-localization with the actin cytoskeleton, and involvement in cell migration was investigated in cultured rat gastric mucosal cells. In stationary cells, CD2AP was localized perinuclearly while E-cadherin was expressed along cell-cell contacts and F-actin formed a branched network and adhesion belts. In migrating cells, CD2AP appeared as thread-like accumulations in the leading edges, colocalizing with F-actin and occasionally with E-cadherin. Intracellular injection of anti-CD2AP significantly retarded the migration speed of the cells suggesting a crucial role for CD2AP in mucosal cell migration, possibly as a scaffolding protein between cell membrane proteins and actin cytoskeleton. Co-immunoprecipitation assays revealed that CD2AP and E-cadherin are in a complex in HGF stimulated cells. It is concluded that CD2AP interacts with E-cadherin and co-localizes with F-actin in the leading edge of migrating cells, and significantly contributes to cell migration in restituting gastric epithelium. 相似文献
53.
Wojciech Walkusz Joclyn E. Paulić Sławomir Kwaśniewski William J. Williams Sally Wong Michael H. Papst 《Polar Biology》2010,33(3):321-335
Composition, abundance, biomass and distribution of zooplankton in the coastal Canadian Beaufort Sea were studied in the summer
of 2005 and 2006. Data were collected from two cross-shelf transects (11 stations in each). Sampling was conducted with vertical
hauls using a conical net of 153-μm mesh size. Our results revealed that there are three ecological zones, Intense Plume,
Diffuse Plume and oceanic, which are primarily shaped by the highly variable Mackenzie River plume. The Intense Plume Grouping
was located at stations influenced greatly by the Mackenzie River, where Podon leuckarti, Pseudocalanus spp., Copepoda nauplii and Limnocalanus macrurus were most abundant. The Diffuse Plume Grouping, that was located in the transitional zone between the river plume and the
ocean, had the highest diversity. This grouping was characterised by high abundance of Copepoda nauplii, Polychaeta larvae,
Pseudocalanus and L. macrurus. The Oceanic Grouping, located farthest from shore beyond the 85-m depth contour, was mainly inhabited by marine taxa—Calanus
glacialis, C. hyperboreus, Triconia (Oncea) borealis and Microcalanus spp.—and had the greatest overall zooplankton abundance and biomass of all groupings. 相似文献
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Leendertz FH Lankester F Guislain P Néel C Drori O Dupain J Speede S Reed P Wolfe N Loul S Mpoudi-Ngole E Peeters M Boesch C Pauli G Ellerbrok H Leroy EM 《American journal of primatology》2006,68(9):928-933
During the period of December 2004 to January 2005, Bacillus anthracis killed three wild chimpanzees (Pan troglodytes troglodytes) and one gorilla (Gorilla gorilla gorilla) in a tropical forest in Cameroon. While this is the second anthrax outbreak in wild chimpanzees, this is the first case of anthrax in gorillas ever reported. The number of great apes in Central Africa is dramatically declining and the populations are seriously threatened by diseases, mainly Ebola. Nevertheless, a considerable number of deaths cannot be attributed to Ebola virus and remained unexplained. Our results show that diseases other than Ebola may also threaten wild great apes, and indicate that the role of anthrax in great ape mortality may have been underestimated. These results suggest that risk identification, assessment, and management for the survival of the last great apes should be performed with an open mind, since various pathogens with distinct characteristics in epidemiology and pathogenicity may impact the populations. An animal mortality monitoring network covering the entire African tropical forest, with the dual aims of preventing both great ape extinction and human disease outbreaks, will create necessary baseline data for such risk assessments and management plans. 相似文献
57.
Maria Ciofani Aviv Madar Carolina GalanMacLean Sellars Kieran MaceFlorencia Pauli Ashish AgarwalWendy Huang Christopher N. ParkurstMichael Muratet Kim M. NewberrySarah Meadows Alex GreenfieldYi Yang Preti JainFrancis K. Kirigin Carmen BirchmeierErwin F. Wagner Kenneth M. Murphy Richard M. MyersRichard Bonneau Dan R. Littman 《Cell》2012,151(2):289-303
58.
Soboliphyme baturini, a stomach-dwelling nematode of American martens (Martes Americana), reaches high levels of infection; however, its effects on the nutritional condition of the host are unknown. To understand the effects of this parasite on American martens, we collected S. baturini and measured abdominal fat deposits from 155 marten carcasses on Prince of Wales Island, southeastern Alaska, in the winter 2006-2007. We analyzed how the dried mass of abdominal fat varied as a function of S. baturini intensity. Parasite intensity and nutritional condition were not correlated; these results suggest that American martens were able to withstand even very high levels of S. baturini infection (up to 178 parasites per host). 相似文献
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Yuan H He R Wan B Wang Y Pauli GF Franzblau SG Kozikowski AP 《Bioorganic & medicinal chemistry letters》2008,18(19):5311-5315
This paper describes a series of modifications of the side chain of micromolide, an anti-tuberculosis natural product. Most of the synthesized compounds showed significantly decreased activities, which suggests that the long aliphatic side chain of micromolide and its double bond are essential to its activity. 相似文献