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191.
192.
Moeller JB Nielsen MJ Reichhardt MP Schlosser A Sorensen GL Nielsen O Tornøe I Grønlund J Nielsen ME Jørgensen JS Jensen ON Mollenhauer J Moestrup SK Holmskov U 《Journal of immunology (Baltimore, Md. : 1950)》2012,188(5):2399-2409
CD163-L1 belongs to the group B scavenger receptor cysteine-rich family of proteins, where the CD163-L1 gene arose by duplication of the gene encoding the hemoglobin scavenger receptor CD163 in late evolution. The current data demonstrate that CD163-L1 is highly expressed and colocalizes with CD163 on large subsets of macrophages, but in contrast to CD163 the expression is low or absent in monocytes and in alveolar macrophages, glia, and Kupffer cells. The expression of CD163-L1 increases when cultured monocytes are M-CSF stimulated to macrophages, and the expression is further increased by the acute-phase mediator IL-6 and the anti-inflammatory mediator IL-10 but is suppressed by the proinflammatory mediators IL-4, IL-13, TNF-α, and LPS/IFN-γ. Furthermore, we show that CD163-L1 is an endocytic receptor, which internalizes independently of cross-linking through a clathrin-mediated pathway. Two cytoplasmic splice variants of CD163-L1 are differentially expressed and have different subcellular distribution patterns. Despite its many similarities to CD163, CD163-L1 does not possess measurable affinity for CD163 ligands such as the haptoglobin-hemoglobin complex or various bacteria. In conclusion, CD163-L1 exhibits similarity to CD163 in terms of structure and regulated expression in cultured monocytes but shows clear differences compared with the known CD163 ligand preferences and expression pattern in the pool of tissue macrophages. We postulate that CD163-L1 functions as a scavenger receptor for one or several ligands that might have a role in resolution of inflammation. 相似文献
193.
Heidarsson PO Bjerrum-Bohr IJ Jensen GA Pongs O Finn BE Poulsen FM Kragelund BB 《Journal of molecular biology》2012,417(1-2):51-64
Neuronal calcium sensor 1 (NCS-1) and orthologs are expressed in all organisms from yeast to humans. In the latter, NCS-1 plays an important role in neurotransmitter release and interacts with a plethora of binding partners mostly through a large solvent-exposed hydrophobic crevice. The structural basis behind the multispecific binding profile is not understood. To begin to address this, we applied NMR spectroscopy to determine the solution structure of calcium-bound human NCS-1. The structure in solution demonstrates interdomain flexibility and, in the absence of a binding partner, the C-terminal tail residues occupy the hydrophobic crevice as a ligand mimic. A variant with a C-terminal tail deletion shows lack of a defined structure but maintained cooperative unfolding and dramatically reduced global stability. The results suggest that the C-terminal tail is important for regulating the conformational stability of the Ca(2+)-activated state. Furthermore, a single amino acid mutation that was recently diagnosed in a patient with autistic spectrum disorder was seen to affect the C-terminal tail and binding crevice in NCS-1. 相似文献
194.
Kosenko A Kang S Smith IM Greene DL Langeberg LK Scott JD Hoshi N 《The EMBO journal》2012,31(14):3147-3156
Several neurotransmitters, including acetylcholine, regulate neuronal tone by suppressing a non-inactivating low-threshold voltage-gated potassium current generated by the M-channel. Agonist dependent control of the M-channel is mediated by calmodulin, activation of anchored protein kinase C (PKC), and depletion of the phospholipid messenger phosphatidylinositol 4,5-bisphosphate (PIP2). In this report, we show how this trio of second messenger responsive events acts synergistically and in a stepwise manner to suppress activity of the M-current. PKC phosphorylation of the KCNQ2 channel subunit induces dissociation of calmodulin from the M-channel complex. The calmodulin-deficient channel has a reduced affinity towards PIP2. This pathway enhances the effect of concomitant reduction of PIP2, which leads to disruption of the M-channel function. These findings clarify how a common lipid cofactor, such as PIP2, can selectively regulate ion channels. 相似文献
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197.
In this article, modified κ-carrageenan hydrogel nanocomposites were synthesized to increase the release ability of carrageenan hydrogels under gastrointestinal conditions. The effect of MgO nanoparticle loading in a model drug (methylene blue) release is investigated. Characterization of hydrogels were carried out using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Field Emission Scanning Electron Microscope (FESEM) and Differential Scanning Calorimetry (DSC). Genipin was used to increase the delivery performance in gastrointestinal tract delivery by decreasing release in simulated stomach conditions and increasing release in simulated intestine conditions. It is shown that the amount of methylene blue released from genipin-cross-linked nanocomposites can be 67.5% higher in intestine medium and 56% lower in the stomach compared to κ-carrageenan hydrogel. It was found that by changing the nanoparticle loading and genipin concentration in the composite, the amount of drug released can be monitored. Therefore, applying nanoparticles appears to be a potential strategy to develop controlled drug delivery especially in gastrointestinal tract studies. 相似文献
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199.
Williams C Bener Aksam E Gunkel K Veenhuis M van der Klei IJ 《Biochimica et biophysica acta》2012,1823(7):1133-1141
Catalase is sorted to peroxisomes via a C-terminal peroxisomal targeting signal 1 (PTS1), which binds to the receptor protein Pex5. Analysis of the C-terminal sequences of peroxisomal catalases from various species indicated that catalase never contains the typical C-terminal PTS1 tripeptide-SKL, but invariably is sorted to peroxisomes via a non-canonical sorting sequence. We analyzed the relevance of the non-canonical PTS1 of catalase of the yeast Hansenula polymorpha (-SKI). Using isothermal titration microcalorimetry, we show that the affinity of H. polymorpha Pex5 for a peptide containing -SKI at the C-terminus is 8-fold lower relative to a peptide that has a C-terminal -SKL. Fluorescence microscopy indicated that green fluorescent protein containing the -SKI tripeptide (GFP-SKI) has a prolonged residence time in the cytosol compared to GFP containing -SKL. Replacing the -SKI sequence of catalase into -SKL resulted in reduced levels of enzymatically active catalase in whole cell lysates together with the occurrence of catalase protein aggregates in the peroxisomal matrix. Moreover, the cultures showed a reduced growth yield in methanol-limited chemostats. Finally, we show that a mutant catalase variant that is unable to properly fold mislocalizes in protein aggregates in the cytosol. However, by replacing the PTS1 into -SKL the mutant variant accumulates in protein aggregates inside peroxisomes. Based on our findings we propose that the relatively weak PTS1 of catalase is important to allow proper folding of the enzyme prior to import into peroxisomes, thereby preventing the accumulation of catalase protein aggregates in the organelle matrix. 相似文献
200.
Satoshi N. Suzuki Masae I. Ishihara Masahiro Nakamura Shin Abe Tsutom Hiura Kosuke Homma Motoki Higa Daisuke Hoshino Kazuhiko Hoshizaki Hideyuki Ida Ken Ishida Motohiro Kawanishi Kazutaka Kobayashi Koichiro Kuraji Shigeo Kuramoto Takashi Masaki Kaoru Niiyama Mahoko Noguchi Haruto Nomiya Satoshi Saito Takeshi Sakai Michinori Sakimoto Hitoshi Sakio Tamotsu Sato Hirofumi Shibano Mitsue Shibata Maki Suzuki Atsushi Takashima Hiroshi Tanaka Masahiro Takagi Naoaki Tashiro Naoko Tokuchi Toshiya Yoshida Yumiko Yoshida 《Ecological Research》2012,27(6):989-990
This data paper reports litter fall data collected in a network of 21 forest sites in Japan. This is the largest litter fall data set freely available in Japan to date. The network is a part of the Monitoring Sites 1000 Project launched by the Ministry of the Environment, Japan. It covers subarctic to subtropical climate zones and the four major forest types in Japan. Twenty-three permanent plots in which usually 25 litter traps were installed were established in old-growth or secondary natural forests. Litter falls were collected monthly from 2004, and sorted into leaves, branches, reproductive structures and miscellaneous. The data provide seasonal patterns and inter-annual dynamics of litter falls, and their geographical patterns, and offer good opportunities for meta-analyses and comparative studies among forests. 相似文献