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51.
Julia O. Sonsin Peter E. Gasson FLS Claudia F. Barros Carmen R. Marcati 《Botanical journal of the Linnean Society. Linnean Society of London》2012,170(2):257-276
A comparative study of the secondary xylem (wood) anatomy of 11 species (38 specimens) occurring in cerrado s.s. and the adjacent gallery forest (both cerrado s.l. habitat) was made with the aim of identifying the anatomical characteristics of ecological value and correlating them with the environmental conditions. The anatomical features that vary, in general, between the two habitats are: growth ring distinctness (well or poorly defined); tyloses and deposits (more abundant in cerrado specimens); gelatinous fibres (more evident in cerrado specimens and in different patterns between habitats); variation in paratracheal and banded parenchyma (more abundant in cerrado); and more cells per parenchyma strand in cerrado. In general, gallery forest specimens have wider vessels, fewer vessels per square millimetre and larger intervessel pits, indicating more efficient water conduction, whereas cerrado s.s. specimens are the opposite, with low vulnerability and mesomorphy indices, demonstrating greater safety under conditions of water stress. © 2012 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, ?? , ??–??. 相似文献
52.
Solveig Herrmann Milena Ninkovic Tobias Kohl éva L?rinczi Luis A. Pardo 《The Journal of biological chemistry》2012,287(53):44151-44163
KV10.1 is a voltage-gated potassium channel aberrantly expressed in many cases of cancer, and participates in cancer initiation and tumor progression. Its action as an oncoprotein can be inhibited by a functional monoclonal antibody, indicating a role for channels located at the plasma membrane, accessible to the antibody. Cortactin is an actin-interacting protein implicated in cytoskeletal architecture and often amplified in several types of cancer. In this study, we describe a physical and functional interaction between cortactin and KV10.1. Binding of these two proteins occurs between the C terminus of KV10.1 and the proline-rich domain of cortactin, regions targeted by many post-translational modifications. This interaction is specific for KV10.1 and does not occur with KV10.2. Cortactin controls the abundance of KV10.1 at the plasma membrane and is required for functional expression of KV10.1 channels. 相似文献
53.
54.
Claudia Götz Andreas Gratz Uwe Kucklaender Joachim Jose 《Biochimica et Biophysica Acta (BBA)/General Subjects》2012,1820(7):970-977
BackgroundAbnormally high activity of protein kinase CK2 is linked to various diseases including cancer. Therefore, the inhibition of CK2 is a promising therapeutic strategy to fight this disease.MethodsWe screened a library of synthetic molecules concerning their capacity to inhibit CK2. The activity of CK2 and their IC50 and Ki values were determined by a capillary electrophoresis assay. The effects of the inhibitor in a cell culture model were analyzed by cell counting, a viability assay, cytofluorimetry and Western blot.ResultsThe best CK2 inhibitor found in this screen was 6,7-dichloro-1,4-dihydro-8-hydroxy-4-[(4-methylphenylamino)methylen]dibenzo [b,d]furan-3(2H)-one, which we refer to as “TF”. TF showed tight binding to CK2 with low IC50 (29 nM) and Ki (15 nM) values. TF inhibited only seven out of 61 human kinases tested (> 70% inhibition). Incubation of LNCaP cells with 50 μM TF for 48 h decreased the intracellular CK2 activity by 50%, confirming that the inhibitor is membrane permeable. The decrease in activity was correlated with a severe reduction in cell viability. The reduction in cell viability is at least partly due to the induction of apoptosis.General significanceIn many cancers the protein kinase CK2 is significantly up-regulated and supports the neoplastic phenotype. New therapeutic strategies should be based on diverse reliable inhibitors to reverse the abnormal high levels to normal settings. 相似文献
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56.
Karlheinz Altendorf Margot Lukas Brigitte Kohl Clemens R. Müuller Heinrich Sandermann 《Journal of cellular biochemistry》1977,6(2):229-238
Techniques for the solubilization and fractionation of integral membrane proteins have been developed in recent years. A small portion of membrane protein (about 2%, proteolipid fraction) will partition into chloroform or 1-butanol, and, in several cases, these proteins retain functional activity. A virtually complete solubilization can be achieved at neutral pH by use of aprotic solvents, like hexamethylphosphoric triamide or N-methylpyrrolidone. At relatively low concentrations (< 3 M) aprotic solvents inhibited β-D-galactoside transport by whole cells and the derivative membrane vesicles of Escherichia coli, but this inhibition could be largely reversed by a simple washing procedure. At higher concentrations of aprotic solvent (5–6 M), 50–80% of the total protein of lactose transport-positive membrane vesicles was solubilized. When these extracts were added to intact lactose transport-negative membrane vesicles, lactose transport was reconstituted, the required energy being provided by either respiration (e.g., addition of D-lactate) or by a K+ diffusion potential established with the aid of valinomycin. The dicyclohexylcarbodiimide (DCCD)-reactive subunit of the E. coli ATPase complex was found to partition into chloroform, and to be amenable to further purification in organic solvent. Ether precipitation and chromatography on DEAE-cellulose and hydroxypropyl-Sephadex G-50 yielded an homogeneous polypeptide of an apparent molecular weight of 9,000. The purified and unlabeled DCCD-reactive protein was incorporated into K+-loaded liposomes, and a membrane potential was generated by the addition of valinomycin. There are indications that the DCCD-reactive protein alone made the membrane specifically permeable for protons. 相似文献
57.
Zhang HC Ye H Conway BR Derian CK Addo MF Kuo GH Hecker LR Croll DR Li J Westover L Xu JZ Look R Demarest KT Andrade-Gordon P Damiano BP Maryanoff BE 《Bioorganic & medicinal chemistry letters》2004,14(12):3245-3250
A novel series of acyclic 3-(7-azaindolyl)-4-(aryl/heteroaryl)maleimides was synthesized and evaluated for activity against GSK-3beta and selectivity versus PKC-betaII, as well as a broad panel of protein kinases. Compounds 14 and 17c potently inhibited GSK-3beta (IC(50)=7 and 26 nM, respectively) and exhibited excellent selectivity over PKC-betaII (325 and >385-fold, respectively). Compound 17c was also highly selective against 68 other protein kinases. In a cell-based functional assay, both 14 and 17c effectively increased glycogen synthase activity by inhibiting GSK-3beta. 相似文献
58.
Recent years have seen several advances in our understanding of the functions of adipose tissue regarding not only the energy storage, but also the regulation of complex metabolic and endocrine functions. In this context, leptin and adiponectin, the two most abundant adipocyte products, represent one of the best example of adipocytokines involved in the control of energy expenditure, lipid and carbohydrate metabolism as well as in the regulation of immune responses. Leptin and adiponectin secretion is counter-regulated in vivo, in relation to degree of adiposity, since plasma leptin concentrations are significantly elevated in obese subjects in proportion to body mass index while adiponectin secretion decreases in relation to the amount of adipose tissue. In this review we focus on the main biological activities of leptin and adiponectin on the lipid and carbohydrate metabolism and on their contribute in regulation of innate and adaptive immune responses. 相似文献
59.
60.
Gesslbauer B Poljak A Handwerker C Schüler W Schwendenwein D Weber C Lundberg U Meinke A Kungl AJ 《Proteomics》2012,12(6):845-858
The versatility of the surface of Borrelia, the causative agent of Lyme borreliosis, is very important in host-pathogen interactions allowing bacteria to survive in ticks and to persist in a mammalian environment. To identify the surface proteome of Borrelia, we have performed a large comparative proteomic analysis on the three most important pathogenic Borrelia species, namely B. burgdorferi (strain B31), B. afzelii (strain K78), and B. garinii (strain PBi). Isolation of membrane proteins was performed by using three different approaches: (i) a detergent-based fractionation of outer membrane proteins; (ii) a trypsin-based partial shedding of outer cell surface proteins; (iii) biotinylation of membrane proteins and preparation of the biotin-labelled fraction using streptavidin. Proteins derived from the detergent-based fractionation were further sub-fractionated by heparin affinity chromatography since heparin-like molecules play an important role for microbial entry into human cells. All isolated proteins were analysed using either a gel-based liquid chromatography (LC)-MS/MS technique or by two-dimensional (2D)-LC-MS/MS resulting in the identification of 286 unique proteins. Ninety seven of these were found in all three Borrelia species, representing potential targets for a broad coverage vaccine for the prevention of Lyme borreliosis caused by the different Borrelia species. 相似文献