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1.
Harriet E. Nilsson Daniel Ambort Malin Bäckström Elisabeth Thomsson Philip J.B. Koeck Gunnar C. Hansson Hans Hebert 《Journal of molecular biology》2014
MUC2 is the major gel-forming mucin of the colon forming a protective gel barrier organized into an inner stratified and an outer loose layer. The MUC2 N-terminus (D1-D2-D′D3 domains) has a dual function in building a net-like structure by disulfide-bonded trimerization and packing the MUC2 polymer into an N-terminal concatenated polygonal platform with the C-termini extending perpendicularly by pH- and calcium-dependent interactions. We studied the N-terminal D′D3 domain by producing three recombinant variants, with or without Myc tag and GFP (green fluorescent protein), and analyzed these by gel filtration, electron microscopy and single particle image processing. The three variants were all trimers when analyzed upon denaturing conditions but eluted as hexamers upon gel filtration under native conditions. Studies by electron microscopy and three-dimensional maps revealed cage-like structures with 2- and 3-fold symmetries. The structure of the MUC2 D3 domain confirms that the MUC2 mucin forms branched net-like structures. This suggests that the MUC2 mucin is stored with two N-terminal concatenated ring platforms turned by 180° against each other, implicating that every second unfolded MUC2 net in mature mucus is turned upside down. 相似文献
2.
Fletcher Warren-Myers Tim Dempster Per Gunnar Fjelldal Tom Hansen Stephen E. Swearer 《PloS one》2015,10(3)
Farmed fish escape and enter the environment with subsequent effects on wild populations. Reducing escapes requires the ability to trace individuals back to the point of escape, so that escape causes can be identified and technical standards improved. Here, we tested if stable isotope otolith fingerprint marks delivered during routine vaccination could be an accurate, feasible and cost effective marking method, suitable for industrial-scale application. We tested seven stable isotopes, 134Ba, 135Ba, 136Ba, 137Ba, 86Sr, 87Sr and 26Mg, on farmed Atlantic salmon reared in freshwater, in experimental conditions designed to reflect commercial practice. Marking was 100% successful with individual Ba isotopes at concentrations as low as 0.001 µg. g-1 fish and for Sr isotopes at 1 µg. g-1 fish. Our results suggest that 63 unique fingerprint marks can be made at low cost using Ba (0.0002 – 0.02 $US per mark) and Sr (0.46 – 0.82 $US per mark) isotopes. Stable isotope fingerprinting during vaccination is feasible for commercial application if applied at a company level within the world’s largest salmon producing nations. Introducing a mass marking scheme would enable tracing of escapees back to point of origin, which could drive greater compliance, better farm design and improved management practices to reduce escapes. 相似文献
3.
Juliane Dinter Jessica Mühlhaus Carolin Leonie Wienchol Chun-Xia Yi Daniela Nürnberg Silke Morin Annette Grüters Josef K?hrle Torsten Sch?neberg Matthias Tsch?p Heiko Krude Gunnar Kleinau Heike Biebermann 《PloS one》2015,10(2)
ObjectiveApplication of 3-iodothyronamine (3-T1AM) results in decreased body temperature and body weight in rodents. The trace amine-associated receptor (TAAR) 1, a family A G protein-coupled receptor, is a target of 3-T1AM. However, 3-T1AM effects still persist in mTaar1 knockout mice, which suggest so far unknown further receptor targets that are of physiological relevance. TAAR5 is a highly conserved TAAR subtype among mammals and we here tested TAAR5 as a potential 3-T1AM target. First, we investigated mouse Taar5 (mTaar5) expression in several brain regions of the mouse in comparison to mTaar1. Secondly, to unravel the full spectrum of signaling capacities, we examined the distinct Gs-, Gi/o-, G12/13-, Gq/11- and MAP kinase-mediated signaling pathways of mouse and human TAAR5 under ligand-independent conditions and after application of 3-T1AM. We found overlapping localization of mTaar1 and mTaar5 in the amygdala and ventromedial hypothalamus of the mouse brain. Second, the murine and human TAAR5 (hTAAR5) display significant basal activity in the Gq/11 pathway but show differences in the basal activity in Gs and MAP kinase signaling. In contrast to mTaar5, 3-T1AM application at hTAAR5 resulted in significant reduction in basal IP3 formation and MAP kinase signaling. In conclusion, our data suggest that the human TAAR5 is a target for 3-T1AM, exhibiting inhibitory effects on IP3 formation and MAP kinase signaling pathways, but does not mediate Gs signaling effects as observed for TAAR1. This study also indicates differences between TAAR5 orthologs with respect to their signaling profile. In consequence, 3-T1AM-mediated effects may differ between rodents and humans. 相似文献
4.
High-pH anion-exchange chromatography with pulsed amperometric detection is a highly sensitive technique that can be used
for detecting changes in sialylation and fucosylation, as well as different branching patterns of N-linked oligosaccharides
in glycoproteins. We examined the N-glycans of α1-acid glycoprotein obtained from twelve patients with various inflammatory
conditions with this technique, as well as traditional concanavalin A crossed affinity immunoelectrophoresis. We found the
chromatographic profiles of N-glycans in all patients with rheumatoid arthritis to be very similar, but significantly different
from normal controls. N-glycans from patients with ulcerative colitis also showed specific alterations in their chromatographic
profiles. However, some heterogeneity was found between these patients, perhaps reflecting changes in glycosylation secondary
to certain states of the disease, or to medical treatment. We conclude that this technique is useful for detailed mapping
of glycosylation changes in α1-acid glycoprotein in clinical samples, and that it may be used to further increase our knowledge
about glycosylation changes in response to inflammatory disease. Abbreviations: AC, acute cholangitis; AGP, α1-acid glycoprotein;
CAIE, crossed affinity immunoelectrophoresis; Con A, concanavalin A; HPAEC-PAD, high-pH anion-exchange chromatography with
pulsed amperometric detection; IEC, ion exchange chromatography; RA, rheumatoid arthritis; SLex, sialyl Lex; UC, ulcerative
colitis
This revised version was published online in November 2006 with corrections to the Cover Date. 相似文献
5.
It is difficult to study the breakdown of lumbar disc tissue over several years of exposure to bending and lifting by experimental methods. In our earlier published study we have shown how a finite element model of a healthy lumbar motion segment was used to predict the damage accumulation location and number of cyclic to failure under different loading conditions. The aim of the current study was to extend the continuum damage mechanics formulation to the degenerated discs and investigate the initiation and progression of mechanical damage. Healthy disc model was modified to represent degenerative discs (Thompson grade III and IV) by incorporating both geometrical and biochemical changes due to degeneration. Analyses predicted decrease in the number of cycles to failure with increasing severity of disc degeneration. The study showed that the damage initiated at the posterior inner annulus adjacent to the endplates and propagated outwards towards its periphery in healthy and grade III degenerated discs. The damage accumulated preferentially in the posterior region of the annulus. However in grade IV degenerated disc damage initiated at the posterior outer periphery of the annulus and propagated circumferentially. The finite element model predictions were consistent with the infrequent occurrence of rim lesions at early age but a much higher incidence in severely degenerated discs. 相似文献
6.
Histone H4K20 tri‐methylation at late‐firing origins ensures timely heterochromatin replication 下载免费PDF全文
Charlotte Grimaud Paulina Prorok Christelle Cayrou Gunnar Schotta Alhassan F Abdelsamie Jérôme Déjardin Marcel Méchali Giuseppe Baldacci Claude Sardet Jean‐Charles Cadoret Aloys Schepers Eric Julien 《The EMBO journal》2017,36(18):2726-2741
Among other targets, the protein lysine methyltransferase PR‐Set7 induces histone H4 lysine 20 monomethylation (H4K20me1), which is the substrate for further methylation by the Suv4‐20h methyltransferase. Although these enzymes have been implicated in control of replication origins, the specific contribution of H4K20 methylation to DNA replication remains unclear. Here, we show that H4K20 mutation in mammalian cells, unlike in Drosophila, partially impairs S‐phase progression and protects from DNA re‐replication induced by stabilization of PR‐Set7. Using Epstein–Barr virus‐derived episomes, we further demonstrate that conversion of H4K20me1 to higher H4K20me2/3 states by Suv4‐20h is not sufficient to define an efficient origin per se, but rather serves as an enhancer for MCM2‐7 helicase loading and replication activation at defined origins. Consistent with this, we find that Suv4‐20h‐mediated H4K20 tri‐methylation (H4K20me3) is required to sustain the licensing and activity of a subset of ORCA/LRWD1‐associated origins, which ensure proper replication timing of late‐replicating heterochromatin domains. Altogether, these results reveal Suv4‐20h‐mediated H4K20 tri‐methylation as a critical determinant in the selection of active replication initiation sites in heterochromatin regions of mammalian genomes. 相似文献
7.
Mulugeta Belay Mengistu Legesse Adane Mihret Yonas Bekele Tom H. M. Ottenhoff Kees L. M. C. Franken Gunnar Bjune Fekadu Abebe 《PloS one》2015,10(4)
Tuberculosis (TB) is among the leading causes of morbidity and mortality. The causative agent, Mycobacterium tuberculosis (Mtb), has evolved virulent factors for entry, survival, multiplication and immune evasion. Rv2031 (also called alpha crystallin, hspX, 16-kDa antigen), one of the most immunogenic latency antigens, is believed to play a key role in long-term viability of Mtb. Here, we report the dynamics of pro-inflammatory (IFN-γ, TNF-α) and anti-inflammatory (IL-10) cytokines against Rv2031 using whole blood assay in human cohorts in a TB endemic setting. Cytokine responses to ESAT-6-CFP-10 were also measured for comparison. Blood samples were collected from smear positive pulmonary TB patients and their contacts at baseline, 6 and 12 months, and from community controls at entry. At baseline, 54.4% of controls and 73.2% of contacts were QFT-GIT test positive. Baseline IFN-γ, TNF-α and IL-10 responses to Rv2031 were significantly higher in controls compared to contacts and untreated patients (p<0.001). Furthermore, untreated patients had significantly higher TNF-α and IL-10 responses to Rv2031 compared to contacts (p<0.001). In contacts and treated patients, IFN-γ, TNF-α and IL-10 responses to Rv2031 significantly increased over 12 months (p<0.0001) and became comparable with the corresponding levels in controls. There was a positive and significant correlation between Rv2031 and ESAT-6-CFP-10 specific cytokine responses in each study group. The fact that the levels of IFN-γ, TNF-α and IL-10 against Rv2031 were highest during latent TB infection may indicate their potential as markers of protection against TB. Taken together, the findings of this study suggest the potential of IFN-γ, TNF-α and IL-10 against Rv2031 as biomarkers of the host response to Mtb during convalescence from, and the absence of, active tuberculosis. 相似文献
8.
The phylogenetic relationships among nine Drosophila species belonging to the obscura group were investigated by establishing the segments displaying banding homologies in their element B (equivalent to the U element of D. subobscura). The phylogenetic ordering of the species was accomplished using overlapping inversions. Two African species, D. kitumensis and D. microlabis, were investigated. These species are homosequential for their element B gene arrangement but differ from that of D. obscura by several rearrangements. Drosophila obscura seems to be most closely related to D. subsilvestris, from which the respective element B gene arrangements differ at least by six inversions. Three species, D. obscura, D. ambigua, and D. tristis, are closely related and form a cluster. Drosophila obscura displays an element B polymorphism for a pericentric inversion for which D. ambigua is fixed for one gene arrangement and D. tristis for the other. Both D. ambigua and D. tristis share a short distal inversion in the small arm of the chromosome, and differ in this respect from D. obscura. Drosophila madeirensis, D. guanche, and D. subobscura all share the same element B gene arrangement, which is acrocentric, but metacentric in all the other species mentioned. It was found that the gene arrangements of the species from the obscura cluster seem to occupy an intermediate position between those of the species of the D. subobscura cluster and those of the African one. The data reported generally are in good agreement with information provided in the literature. 相似文献
9.
Dan -E. Nilsson Kurt Hamdorf Gunnar Höglund 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1992,170(2):217-226
Summary In the superposition eyes of the sphingid moth Deilephila and the neuropteran Ascalaphus, adjustment to different intensities is subserved by longitudinal migrations of screening pigment in specialized pigment cells. Using ophthalmoscopic techniques we have localized the light-sensitive trigger that controls pigment position.In both species, local illumination of a small spot anywhere within the eye glow of a dark-adapted eye evokes local light adaptation in the ommatidia whose facets receive the light. Details of the response pattern demonstrate that a distal light-sensitive trigger is located axially in the ommatidium, just beneath the crystalline cone, and extends with less sensitivity deep into the clear zone. The distal trigger in Deilephila was shown to be predominantly UV sensitive, and a UV-absorbing structure, presumably the distal trigger, was observed near the proximal tip of the crystalline cone.In Ascalaphus we also found another trigger located more proximally, which causes local pigment reaction in the ommatidia whose rhabdoms are illuminated (the centre of the eye glow). The light-sensitive trigger for this response appears to be the rhabdom itself. 相似文献
10.
Stanislaw Karpinski Gunnar Wingsle Olof Olsson Jan -Erik Hällgren 《Plant molecular biology》1992,18(3):545-555
A Scots pine (Pinus sylvestris L.) cDNA library was screened with two heterologous cDNA probes (P31 and T10) encoding cytosolic and chloroplastic superoxide dismutases (SOD) from tomato. Several positive clones for cytosolic and chloroplastic superoxide dismutases were isolated, subcloned, mapped and sequenced. One of the cDNA clones (PS3) had a full-length open reading frame of 465 bp corresponding to 154 amino acid residues and showed approximately 85% homology with the amino acid sequences of angiosperm cytosolic SOD counterparts. Another cDNA clone (PST13) was incomplete, but encoded a putative protein with 93% homology to pea and tomato chloroplastic superoxide dismutase. The derived amino acid sequence from both cDNA clones matched the corresponding N-terminal amino acid sequence of the purified mature SOD isozymes. Northern blot hybridizations showed that, cytosolic and chloroplastic CuZn-SOD are expressed at different levels in Scots pine organs. Sequence data and Southern blot hybridization confirm that CuZn-SODs in Scots pine belong to a multigene family. The results are discussed in relation to earlier observations of CuZn-SODs in plants. 相似文献