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941.
942.
In Saccharomyces cerevisiae, a branched multistep phosphorelay signaling pathway regulates cellular adaptation to hyperosmotic stress. YPD1 functions as a histidine-phosphorylated protein intermediate required for phosphoryl group transfer from a membrane-bound sensor histidine kinase (SLN1) to two distinct response regulator proteins (SSK1 and SKN7). These four proteins are evolutionarily related to the well-characterized "two-component" regulatory proteins from bacteria. Although structural information is available for many two-component signaling proteins, there are very few examples of complexes between interacting phosphorelay partners. Here we report the first crystal structure of a prototypical monomeric histidine-containing phosphotransfer (HPt) protein YPD1 in complex with its upstream phosphodonor, the response regulator domain associated with SLN1. 相似文献
943.
Using an antibody specific and selective to mitochondrial uncoupling protein 1 (UCP1) peptide, this study confirms the observation that UCP 1 is present in thymocytes isolated from UCP 1 wild-type, but not UCP 1 knock-out mice. UCP 1 is also shown to be present in thymocytes isolated from rat. It was also demonstrated that an antibody raised to the full-length UCP 1 protein appears to be non-specific for UCP 1, as it detects protein in UCP 1 wild-type and UCP 1 knock-out mice, protein in mitochondria isolated from brown adipose tissue of both UCP 1 wild-type and UCP 1 knock-out mice, as well as detecting protein in mitochondria isolated from rat spleen, kidney, skeletal muscle and liver, tissues that do not express UCP 1. We were also able to show that CIDEA, a soluble protein with a suggested role in regulating UCP 1 function, is equally abundant in thymocytes from UCP 1 wild-type and UCP 1 knock-out mice. Taken together our data demonstrate that (a) UCP 1 is present in rat and mouse thymocytes, (b) that the antibody to full-length UCP 1 is not specific for UCP 1 and (c) that the absence of UCP 1 does not affect native expression of CIDEA in thymocytes. 相似文献
944.
Adams AE Hanrahan O Nolan DN Voorheis HP Fallon P Porter RK 《Biochimica et biophysica acta》2008,1777(2):115-117
The aim of this study was to demonstrate the constitutive expression of mitochondrial uncoupling protein 1 (UCP 1) in pure thymocytes using laser scanning confocal microscopic imagery. To that end we probed thymocytes from UCP 1 knock-out and wild-type mice. Mitochondrial location in thymocytes was determined using Mitotracker Red and the nucleus was labelled using Hoescht stain. We demonstrate that all cells investigated were thymocytes as determined by a monoclonal antibody specific for the thymocyte surface marker Thy 1 (CD90) pre-coupled to a fluorescent labelled (Alexa 448, green). Using a primary peptide antibody specific to UCP 1, and secondary fluorescently labelled (Alexa 647, magenta) antibody, we were able to demonstrate that UCP 1 is associated with mitochondria in thymocytes from UCP 1 wild-type mice but not thymocytes from UCP1-knock-out mice. These are the first images demonstrating the presence of UCP 1 in thymocyte mitochondria, in situ, and the first to clearly demonstrate UCP 1 expression in cells other than brown adipocytes. We conclude that mouse thymocytes contain UCP 1 in their mitochondria. 相似文献
945.
Kuffová L Netuková M Duncan L Porter A Stockinger B Forrester JV 《Journal of immunology (Baltimore, Md. : 1950)》2008,180(3):1353-1361
We investigated Ag trafficking from the cornea and T effector cell activation in secondary lymphoid tissue after corneal transplantation. In preliminary experiments, the central cornea was shown to contain a population of CD45(+), CD11b(+), CD11c- cells, with a few MHC class II(+) cells, and F4/80(+) cells. However, MHC class II(+) passenger leukocytes in donor cornea after allografting did not traffic to the draining lymph node. Instead, Ag (plasmid) delivered to the eye via the donor cornea during allograft was detected in host CD11c(+) and F4/80(+) APC in the draining lymph nodes and spleen. The earliest detection of APC-associated Ag was at 6 h in the draining lymph node and 24 h in the spleen. After 48 h Ag was not detected in the draining lymph node but was still present in the spleen. Ag applied to the donor corneal epithelium before allografting induced Ag-specific T cell activation and expansion in the draining lymph node with a peak response at 4-6 days, indicating that cross-presentation of Ag had occurred. We conclude therefore, that Ag is transported from the donor cornea within host APC and that this event occurs within hours after grafting. Ag is cross-presented to host CD4(+) T cells on MHC class II and leads to the activation of Ag-specific effector T cells and clonal expansion in the draining lymph node. 相似文献
946.
Simple and Safe Method for Simultaneous Isolation of Microbial RNA and DNA from Problematic Populations
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Simon McIlroy Kate Porter Robert J. Seviour Daniel Tillett 《Applied microbiology》2008,74(21):6806-6807
We describe a novel, rapid, and safe method for extracting RNA and DNA from refractory microbes, which avoids the use of phenol or chloroform. It has been used successfully to isolate high-quality nucleic acids from pure cultures and environmental populations known to resist widely used extraction protocols. 相似文献
947.
The skeletal system, while characterized by a hard tissue component, is in fact an extraordinarily dynamic system, with disparate functions ranging from structural support, movement and locomotion and soft-organ protection, to the maintenance of calcium homeostasis. Amongst these functions, it has long been known that mammalian bones house definitive hematopoiesis. In fact, several data demonstrate that the bone microenvironment provides essential regulatory cues to the hematopoietic system. In particular, interactions between the bone-forming cells, or osteoblasts, and the most primitive Hematopoietic Stem Cells (HSC) have recently been defined. This review will focus mainly on the role of osteoblasts as HSC regulatory cells, discussing the signaling mechanisms and molecules currently thought to be involved in their modulation of HSC behavior. We will then review additional cellular components of the HSC niche, including endothelial cells and osteoclasts. Finally, we will discuss the potential clinical implications of our emerging understanding of the complex HSC microenvironment. 相似文献
948.
D. A. Scruton C. J. Pennell C. E. Bourgeois R. F. Goosney L. King R. K. Booth W. Eddy T. R. Porter L. M. N. Ollerhead K. D. Clarke 《Hydrobiologia》2008,596(1):225-239
Microalgal biofilms are associated with considerable variability in the properties of natural sediments, yet little effort
has been made to isolate micro-scale spatial and temporal changes in sediment properties caused by the growth of a biofilm.
Understanding the changes associated with biofilm growth and quantifying the time scales over which these changes occur is
important for developing suitable experimental designs and for understanding how biofilms mediate sediment properties and
processes. The development of a microphytobenthic biofilm and associated changes in the sediment was investigated over 45 days
in the laboratory. The biogeochemical properties of the sediment: bulk density, water content, chlorophyll a concentration and colloidal carbohydrate concentration were measured on a sub-millimetre scale in the top 2 mm. The erosion
threshold was measured with a Cohesive Strength Meter (CSM). Biofilm development was rapid, with changes in the properties
occurring after 1 day and a visible film forming after just 3 days. The largest changes in sediment properties tended to occur
in the surface 200 μm through time, with some variables also showing a differing response with depth. There were significant
changes in water content, chlorophyll a concentration, colloidal carbohydrate concentration and erosion threshold in the surface 2 mm, with a general trend to increase
with time. Bulk density was highly variable and did not show a consistent pattern of change with time. Erosion threshold was
positively correlated with water content, chlorophyll a and colloidal carbohydrate in the surface 200 μm and these were also positively correlated with each other. Low Temperature
Scanning Electron Microscopy (LTSEM) images revealed changes in the surface sediment structure and the formation of a thick
multi-layer biofilm. The rapidity of biofilm growth and development and the associated changes to the sediment should be considered
when designing experiments that investigate biofilms and properties of sediments and/or that involve biocide treatments or
disturbance to the sediment. 相似文献
949.
In this article we present a biogeographical assessment of species diversity within the Mysida (Crustacea: Malacostraca: Peracarida)
from inland waters. Inland species represent 6.7% (72 species) of mysid diversity. These species represent three of the four
families within the Mysida (Lepidomysidae, Stygiomysidae, and Mysidae) and are concentrated in the Palaearctic and Neotropical
regions. The inland mysid species distributional patterns can be explained by four main groups representing different freshwater
invasion routes: (1) Subterranean Tethyan relicts (24 spp.); (2) Autochthonous Ponto-Caspian endemics (20 spp.); (3) Mysis spp. ‘Glacial Relicts’ (8 spp.); and (4) Euryhaline estuarine species (20 spp.). The center of inland mysid species diversity
is the Ponto-Caspian region, containing 24 species, a large portion of which are the results of a radiation in the genus Paramysis.
Electronic Supplementary Material The online version of this article (doi:) contains supplementary material, which is available to authorized users.
Guest editors: E. V. Balian, C. Lévêque, H. Segers and K. Martens
Freshwater Animal Diversity Assessment 相似文献
950.
The use of polyamino acids in asymmetric organic synthesis is reviewed. Particular emphasis is placed on the asymmetric epoxidation of alpha,beta-unsaturated ketones with hydrogen peroxide in the presence of polyalanine or polyleucine, and further transformations of the epoxide products. 相似文献