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111.
Disappearance of the budding yeast Bub2-Bfa1 complex from the mother-bound spindle pole contributes to mitotic exit
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Fraschini R D'Ambrosio C Venturetti M Lucchini G Piatti S 《The Journal of cell biology》2006,172(3):335-346
Budding yeast spindle position checkpoint is engaged by misoriented spindles and prevents mitotic exit by inhibiting the G protein Tem1 through the GTPase-activating protein (GAP) Bub2/Bfa1. Bub2 and Bfa1 are found on both duplicated spindle pole bodies until anaphase onset, when they disappear from the mother-bound spindle pole under unperturbed conditions. In contrast, when spindles are misoriented they remain symmetrically localized at both SPBs. Thus, symmetric localization of Bub2/Bfa1 might lead to inhibition of Tem1, which is also present at SPBs. Consistent with this hypothesis, we show that a Bub2 version symmetrically localized on both SPBs throughout the cell cycle prevents mitotic exit in mutant backgrounds that partially impair it. This effect is Bfa1 dependent and can be suppressed by high Tem1 levels. Bub2 removal from the mother-bound SPB requires its GAP activity, which in contrast appears to be dispensable for Tem1 inhibition. Moreover, it correlates with the passage of one spindle pole through the bud neck because it needs septin ring formation and bud neck kinases. 相似文献
112.
Brunner P Sözer-Topcular N Jockers R Ravid R Angeloni D Fraschini F Eckert A Müller-Spahn F Savaskan E 《European journal of histochemistry : EJH》2006,50(4):311-316
The pineal hormone melatonin is involved in physiological transduction of temporal information from the light dark cycle to circadian and seasonal behavioural rhythms, as well as possessing neuroprotective properties. Melatonin and its receptors MT1 and MT2, which belong to the family of G protein-coupled receptors, are impaired in Alzheimer's disease (AD) with severe consequences to neuropathology and clinical symptoms. The present data provides the first immunohistochemical evidence for the cellular localization of the both melatonin receptors in the human pineal gland and occipital cortex, and demonstrates their alterations in AD. We localized MT1 and MT2 in the pineal gland and occipital cortex of 7 elderly controls and 11 AD patients using immunohistochemistry with peroxidase-staining. In the pineal gland both MT1 and MT2 were localized to pinealocytes, whereas in the cortex both receptors were expressed in some pyramidal and non-pyramidal cells. In patients with AD, parallel to degenerative tissue changes, there was an overall decrease in the intensity of receptors in both brain regions. In line with our previous findings, melatonin receptor expression in AD is impaired in two additional brain areas, and may contribute to disease pathology. 相似文献
113.
114.
Santini MT Rainaldi G Ferrante A Indovina P Donelli G Indovina PL 《Bioelectromagnetics》2006,27(2):132-141
The possibility that a sinusoidal 50 Hz magnetic field with a magnetic flux density of 1 mT can damage MG-63 osteosarcoma spheroids and induce variations in the invasive properties of these three-dimensional model systems after 2 days of exposure was investigated. Specifically, possible damage induced by these fields was examined by determining changes in spheroid surface morphology (light microscopy), growth (spheroid diameter and protein content determination), lactate dehydrogenase release, and reduced glutathione amount. Possible changes in the invasive properties were studied by invasion chambers. The results show no induction of cell damage by ELF fields while invasion chamber assays demonstrate a significant increase in the invasive potential of exposed spheroids. In order to determine if the fibronectin or hyaluronan receptors are involved, Western blot analysis was conducted on these two proteins. No significant variations were observed in either receptor in MG-63 multicellular tumor spheroids. 相似文献
115.
Di Ilio V Pasquariello N van der Esch AS Cristofaro M Scarsella G Risuleo G 《Molecular and cellular biochemistry》2006,287(1-2):69-77
Neem oil is a natural product obtained from the seeds of the tree Azadirachta indica. Its composition is very complex and the oil exhibits a number of biological activities. The most studied component is the terpenoid azadirachtin which is used for its insecticidal and putative antimicrobial properties. In this report we investigate the biological activity of partially purified components of the oil obtained from A. indica. We show that the semi-purified fractions have moderate to strong cytotoxicity. However, this is not attributable to azadirachtin but to other active compounds present in the mixture. Each fraction was further purified by appropriate extraction procedures and we observed a differential cytotoxicity in the various sub-fractions. This led us to investigate the mode of cell death. After treatment with the oil fractions we observed positivity to TUNEL staining and extensive internucleosomal DNA degradation both indicating apoptotic death. The anti-proliferative properties of the neem oil-derived compounds were also assayed by evaluation of the nuclear PCNA levels (Proliferating Cell Nuclear Antigen). PCNA is significantly reduced in cells treated with a specific fraction of neem oil. Finally, our results strongly suggest a possible involvement of the mitochondrial pathway in the apoptotic death. 相似文献
116.
Saucedo AL Del Rio-Portilla F Picco C Estrada G Prestipino G Possani LD Delepierre M Corzo G 《Biochimica et biophysica acta》2012,1824(3):478-487
The three-dimensional structures of the long-chain mammalian scorpion β-toxin CssII from Centruroides suffusus suffusus and of its recombinant form, HisrCssII, were determined by NMR. The neurotoxin CssII (nCssII) is a 66 amino acid long peptide with four disulfide bridges; it is the most abundant and deadly toxin from the venom of this scorpion. Both native and recombinant CssII structures were determined by nuclear magnetic resonance using a total of 828 sequential distance constraints derived from the volume integration of the cross peaks observed in 2D NOESY spectra. Both nCssII and HisrCssII structures display a mixed α/β fold stabilized by four disulfide bridges formed between pairs of cysteines: C1-C8, C2-C5, C3-C6, and C4-C7 (the numbers indicate the relative positions of the cysteine residues in the primary structure), with a distortion induced by two cis-prolines in its C-terminal part. The native CssII electrostatic surface was compared to both the recombinant one and to the Cn2 toxin, from the scorpion Centruroides noxius, which is also toxic to mammals. Structural features such N- and C-terminal differences could influence toxin specificity and affinity towards isoforms of different sub-types of Na(v) channels. 相似文献
117.
Cosenza G Pauciullo A Mancusi A D'Avino A Colimoro L Di Berardino D Ramunno L 《Biochemical genetics》2012,50(1-2):73-83
This study was undertaken to detect polymorphisms in the goat and sheep mannose-binding lectin encoding gene (MBL2) and to explore allelic variability of this gene in these two species. The analysis and comparison of the sequences obtained from sheep showed 13 polymorphic sites, six in the promoter and seven in exon 1, four of which were of the missense type. In the goats, 12 polymorphic sites were detected, five intronic, five in the promoter, and one exonic. The exon site was responsible for an amino acid change. Mutations detected at the MBL2 locus in the sheep are of particular interest, being potentially responsible for the alterations of gene expression. A population survey involved 102 ewes of the Sardinian breed and 218 goats of the Nicastrese breed, all reared in southern Italy. 相似文献
118.
Bois noir (BN) is one of the main phytoplasma diseases of grapevine (Vitis vinifera). It is widespread, and can cause severe losses in European vineyards. The infective agent colonizes phloem elements and induces visible symptoms of leaf yellowing or reddening after a relatively long incubation period. As the most sensitive cultivars to BN, Chardonnay plants were grouped as healthy or symptomatic in spring, based on the records from the previous year. Leaf gas exchange and chlorophyll a fluorescence were measured weekly from July to September in healthy plants, and in symptomatic and asymptomatic leaves from symptomatic plants. The midday relative water content (mRWC) was measured once per month. The detection of phytoplasma DNA by nested-polymerase chain reaction revealed BN infection in symptomatic leaf samples at the end of September. A significant decrease in pigment content and maximum quantum efficiency of photosystem II (Fv/Fm) of these symptomatic leaves was detected from July to September, although in the asymptomatic leaves of the symptomatic plants the net photosynthesis (Pn) decrease was not significant. In the leaves from the healthy plants, Pn and transpiration were relatively stable. Of note, in July, an initially healthy plant showed a strong Pn reduction that was followed by visible leaf yellowing symptoms only in August. The phytoplasma infection also stimulated significant reductions in mRWC of the symptomatic leaves, with a final large decrease in yield. 相似文献
119.
Balboni G Congiu C Onnis V Maresca A Scozzafava A Winum JY Maietti A Supuran CT 《Bioorganic & medicinal chemistry letters》2012,22(9):3063-3066
An inhibition study of several carbonic anhydrase (CA, EC 4.2.1.1) isoforms with flavones and aminoflavones, compounds possessing a rather similar scaffold with the coumarins, recently discovered inhibitors of this enzyme, is reported. The natural product flavone and some of its hydroxylated derivatives did not show time-dependent inhibition of the CAs, sign that they are not hydrolyzed within the enzyme active site as the (thio)coumarins and lactones. These compounds were low micromolar inhibitors of hCA I, II, IX and XII, with K(I)s in the range of 1.88-9.07 μM. A series of substituted 2-amino-3-phenyl-4H-chromen-4-ones, incorporating chloro- and methoxy substituents in various positions of the heterocycle, were then prepared and assayed as hCA I and II inhibitors, showing activity in the micromolar range. Some of these derivatives, as well as cis+trans resveratrol, were then assayed for the inhibition of all catalytically active mammalian CA isoforms, hCA I, II, III, IV, VA, VB, VI, VII, IX, XII, XIII, XIV and mCA XV (h=human, m=murine enzyme). These derivatives inhibited these CAs in the submicromolar-low micromolar range. Flavones, although not as active as the coumarins, may be considered as interesting leads for the design of non-sulfonamide CA inhibitors. 相似文献
120.
Gianfranco De Feo Giacomo Chiabrando Nunzia Cannovo Antonio Galluccio Carlo Tomino 《PloS one》2012,7(11)