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81.
From examination of the central axonal projections of sensory bristles on the notum of several species of Drosophilidae, we demonstrate different features that may indicate different functions for macro- and microchaetes. The large macrochaetes have conserved arborizations that correlate with their conserved position. Nevertheless, we find evidence for only two discrete projection patterns for bristles in the dorsocentral (DC) row, even when there may be four or five bristles present. We show that the small microchaetes of Drosophila melanogaster display regional specificity and subsets of contiguous bristles project to a common region in the thoracic ganglion. Interestingly, the axons of each of these subsets also form a specific fasciculation group on the scutum before joining the axon of a particular macrochaete. The positions of microchaetes on the scutum and the shape of the fasciculation groups vary between closely related species. There is no correlation between body size, bristle patterns, and fasciculation patterns. Furthermore, none of these traits correlate with the phylogenetic relationships between the species studied. We discuss the possibility that macro- and microchaetes may have different functions and that these have implications for evolutionary constraints on bristle patterns. 相似文献
82.
Furukawa N Ongusaha P Jahng WJ Araki K Choi CS Kim HJ Lee YH Kaibuchi K Kahn BB Masuzaki H Kim JK Lee SW Kim YB 《Cell metabolism》2005,2(2):119-129
Accumulating evidence indicates an important role for serine phosphorylation of IRS-1 in the regulation of insulin action. Recent studies suggest that Rho-kinase (ROK) is a mediator of insulin signaling, via interaction with IRS-1. Here we show that insulin stimulation of glucose transport is impaired when ROK is chemically or biologically inhibited in cultured adipocytes and myotubes and in isolated soleus muscle ex vivo. Inactivation of ROK also reduces insulin-stimulated IRS-1 tyrosine phosphorylation and PI3K activity. Moreover, inhibition of ROK activity in mice causes insulin resistance by reducing insulin-stimulated glucose uptake in skeletal muscle in vivo. Mass spectrometry analysis identifies IRS-1 Ser632/635 as substrates of ROK in vitro, and mutation of these sites inhibits insulin signaling. These results strongly suggest that ROK regulates insulin-stimulated glucose transport in vitro and in vivo. Thus, ROK is an important regulator of insulin signaling and glucose metabolism. 相似文献
83.
We have extended an earlier study, in which we characterized in detail the electrostatic potentials on the inner and outer surfaces of a group of carbon and BxNx model nanotubes, to include several additional ones with smaller diameters plus a new category, C2xBxNx. The statistical features of the surface potentials are presented and analyzed for a total of 19 tubes as well as fullerene and a small model graphene. The potentials on the surfaces of the carbon systems are relatively weak and rather bland; they are much stronger and more variable for the BxNx and C2xBxNx. A qualitative correlation with free energies of solvation indicates that the latter two categories should have considerably greater water solubilities. The inner surfaces are generally more positive than the corresponding outer ones, while both positive and negative potentials are strengthened by increasing curvature. The outsides of BxNx tubes have characteristic patterns of alternating positive and negative regions, while the insides are strongly positive. In the closed C2xBxNx systems, half of the C–C bonds are double-bond-like and have negative potentials above them; the adjacent rows of boron and nitrogens show the usual BxNx pattern. When the C2xBxNx tubes are open, with hydrogens at the ends, the surface potentials are dominated by the B+–H– and N––H+ linkages.Figure Calculated electrostatic potential on the molecular surface of closed (6,0) B48N48; a is an outside view, while b shows the interior. Color ranges, in kcal mol–1: red, greater than 20; yellow, between 20 and 0; green, between 0 and –10; blue, between –10 and –20; purple, more negative than –20 相似文献
84.
Orsini MJ Nesmelova I Young HC Hargittai B Beavers MP Liu J Connolly PJ Middleton SA Mayo KH 《The Journal of biological chemistry》2005,280(9):8134-8142
Nociceptin, a 17 amino acid opioid-like peptide that has an inhibitory effect on synaptic transmission in the nervous system, is involved in learning, memory, attention, and emotion and is also implicated in the perception of pain and visual, auditory, and olfactory functions. In this study, we investigated the NMR solution structure of nociceptin in membrane-like environments (trifluoroethanol and SDS micelles) and found it to have a relatively stable helix conformation from residues 4-17 with functionally important N-terminal residues being folded aperidoically on top of the helix. In functional assays for receptor binding and calcium flux, alanine-scanning variants of nociceptin indicated that functionally important residues generally followed helix periodicity, consistent with the NMR structural model. Structure-activity relationships allowed identification of pharmacophore sites that were used in small molecule data base searches, affording hits with demonstrated nociceptin receptor binding affinities. 相似文献
85.
T cells from TCR transgenic mice, expressing receptors specific for an allogeneic MHC class I peptide, were used to track T cell activation and migration in normal adoptive recipients that were subsequently transplanted with heterotopic hearts that were syngeneic except for a transgenic MHC class I antigen. T cells rapidly disappeared from the blood into the lymphoid tissues where they were activated within one day after transplantation. T cells initially formed discrete clusters in the spleen and lymph nodes. After proliferating for 2-4 days in lymphoid tissues, T cells reappeared in the blood and migrated to the heart and the intestines. The T cells underwent another round of proliferation in the heart, but not the intestines, and induced cardiac rejection uniformly on 6 day. 相似文献
86.
M. Linhová P. Patáková J. Lipovský P. Fribert L. Paulová M. Rychtera K. Melzoch 《Folia microbiologica》2010,55(4):340-344
Clostridium pasteurianum forms acetic and butyric acids in an initial growth phase, which is a typical feature of clostridial acetone-butanol fermentation
where an initial accumulation of acids is followed by production of solvents 1-butanol, acetone and ethanol. The initiation
of the solvent production coupled with endospore formation leads to decrease of cell-wall thickness; thinner cell wall is
more resistant against solvents and dyes. These changes can be observed by the method based on adaptation of Gram staining.
The cell wall of G+ bacteria allows the entry of hexidium iodide and rhodamine 123, whereas the outer membrane of G− bacteria does not allow the uptake and therefore G+ bacteria are stained with higher fluorescence intensity than G− bacteria. The ratio of fluorescence intensity (FI) to forward scatter (FSC) was determined to correspond to G+ bacteria when clostridia were producing less solvents. The significant drop of the ratio FI to FSC to the level corresponding
to G− bacteria is detected after initiation of solvent production. 相似文献
87.
Michelle Pacholec John E. Bleasdale Boris Chrunyk David Cunningham Declan Flynn Robert S. Garofalo David Griffith Matt Griffor Pat Loulakis Brandon Pabst Xiayang Qiu Brian Stockman Venkataraman Thanabal Alison Varghese Jessica Ward Jane Withka Kay Ahn 《The Journal of biological chemistry》2010,285(11):8340-8351
88.
Producing a robust phylogenetic reconstruction for Polychaeta using either morphological or molecular data sets has proven very difficult. There remain many conflicts between morphological analyses and hypotheses based on DNA data, the latter principally derived from 18S rRNA sequences. For the present study a data set covering a broad range of polychaete diversity was assembled, including 38 new sequences from 21 species. Besides available 18S rRNA data, five additional gene segments were examined: the D1 and D9-10 expansion regions of 28S rRNA, histone H3, snU2 RNA and cytochrome c oxidase subunit I. Maximum parsimony, maximum likelihood and Bayesian analyses were conducted.Annelida and Mollusca were reciprocally monophyletic in maximum likelihood analyses, but Polychaeta included a cephalopod in maximum parsimony analyses, and a patellogastropod in Bayesian analyses. When rooted on the Mollusca, optimal topologies from maximum likelihood analyses showed a recognisable basal group of taxa, including Oweniidae, Chaetopteridae and Amphinomidae. The six studied phyllodocidan families plus Orbiniidae (as the sister group of the scale-worms) formed the next most basal group. All analyses support the inclusion of Echiura, Clitellata and Siboglinidae within polychaetes. Bayesian analyses show Echiura as the sister group of Capitellidae, in agreement with previous 18S rRNA results, In contrast, Echiura formed the sister group to Trichobranchidae in maximum likelihood and maximum parsimony analyses.Supra-familial groupings consistently recovered within Polychaeta in the analyses are: (i) Terebellida without Ampharetidae; (ii) Scolecida (excepting Orbiniidae); (iii) Eunicidae, Lumbrineridae and Clitellata; and (iv) “Cirratuliformia” (including Sternaspidae) plus Sabellidae, Serpulidae and Spionidae. 相似文献
89.
90.
Zhang H Loriaux P Eng J Campbell D Keller A Moss P Bonneau R Zhang N Zhou Y Wollscheid B Cooke K Yi EC Lee H Peskind ER Zhang J Smith RD Aebersold R 《Genome biology》2006,7(8):R73-12
There has been considerable recent interest in proteomic analyses of plasma for the purpose of discovering biomarkers. Profiling N-linked glycopeptides is a particularly promising method because the population of N-linked glycosites represents the proteomes of plasma, the cell surface, and secreted proteins at very low redundancy and provides a compelling link between the tissue and plasma proteomes. Here, we describe UniPep http://www.unipep.org--a database of human N-linked glycosites--as a resource for biomarker discovery. 相似文献