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21.
The observation of the regulation of fast protein dynamics in a cellular context requires the development of reliable technologies. Here, a signal regulation cascade reliant on the stimulus-dependent acceleration of the bidirectional flow of mitogen-activated protein kinase (extracellular signal-regulated kinase) across the nuclear envelope was visualized by reversible protein highlighting. Light-induced conversion between the bright and dark states of a monomeric fluorescent protein engineered from a novel coral protein was employed. Because of its photochromic properties, the protein could be highlighted, erased, and highlighted again in a nondestructive manner, allowing direct observation of regulated fast nucleocytoplasmic shuttling of key signaling molecules. 相似文献
22.
Hideaki Matsumoto 《Soil Science and Plant Nutrition》2005,51(5):613-615
Aluminum (Al) is a major element in the soil; 30–40% of arable land is acidic. Solubilized Al ion in acid soils inhibits root elongation. Intensive research on the Al tolerance mechanism has been conducted in the past few decades. Mechanism of Al tolerance can be classified into Al exclusion mechanism and intracellular tolerance mechanism. Efflux of organic acids from roots upon receiving the Al signal is the major Al exclusion mechanism. Efflux of organic acids through the channel in the plasma membrane was confirmed, and the gene specifically encoding malate transporter in Al-tolerant wheat was discovered recently. The regulatory mechanism in the efflux of organic acids upon protein phosphorylation may be operative. The production of reactive oxygen species (ROS) and their scavenging system are thought to be important in the intracellular tolerance mechanism. 相似文献
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24.
Iwamori T Oosawa M Nukumi N Kano K Sudo K Naito K Tojo H 《The Journal of reproduction and development》2005,51(5):579-592
It has been suggested that whey acidic protein (WAP) may function as a protease inhibitor. However, the actual function of WAP remains obscure. We investigated the histological development of the mammary glands of transgenic mice ubiquitously expressing WAP and CAG/WAP transgene. Ubiquitous expression of WAP induced aberrant development of the lobular alveoli of the mammary glands: mammary alveoli that were either aberrantly large or small in size increased in number in the developing mammary glands of these transgenic females during pregnancy and lactation. The expression of beta-casein was precociously induced in the mammary glands of the transgenic females during early pregnancy and accompanying this was a histological observation that abnormally developed lobular alveoli filled with milk proteins appeared in the mammary glands of transgenic females during early pregnancy. However, during lactation, the development of mammary glands was impaired in transgenic females. To investigate the possible paracrine action of WAP associated with mammary gland aberration, we transplanted the mammary tissue of CAG/EGFP transgenic females into the fat pad of virgin CAG/WAP transgenic females and initiated pregnancy by mating. The development of mammary tissue transplanted to the recipient was histologically examined on day 3 of lactation. The results revealed that the development of grafted mammary tissues was impaired in a manner similar to that of the mammary glands of CAG/WAP transgenic females, indicating that the inhibitory effect of WAP acts via a paracrine mechanism. In vitro experiments using HC11 cells with forced expression of exogenous WAP demonstrated the inhibitory function of WAP on proliferation of mammary epithelial cells. 相似文献
25.
Katayama H Hori M Sato K Kajita M Ozaki H Karaki H Ohashi K Kai C 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2004,66(4):409-415
Several studies have indicated that viruses require a specific cytoskeletal structure for replication in host cells. In this study, we examined the role of actin fiber in the replication of canine distemper virus (CDV), belonging to the Morbillivirus genus of the family Paramyxoviridae. For this purpose, we used two actin depolymerizing agents, cytochalasin-D (C-D) and mycalolide-B (ML-B). In Vero cells, C-D disrupted actin fibers distributed in the cytosol, but peripheral actin fibers remained intact. On the other hand, ML-B completely disrupted the actin fibers distributed in both areas. Treatment of Vero cells with C-D or ML-B inhibited the replication of CDV. Double staining of CDV-infected Vero cells with antibody to N-protein and rhodamine-phalloidin revealed the presence of N-protein in mid-cytoplasm. However, the N-protein was specifically localized at the submembrane region in the presence of C-D, whereas it was clustered in the presence of ML-B. Viral mRNA levels of N- and H-proteins were rather increased by treatment with C-D or ML-B. The treatment with ML-B strongly inhibited N-protein expression, whereas C-D only slightly inhibited N-protein expression. These results suggest that actin microfilaments distributed in the cytoplasm and on the membrane region in host cells may have a different role in the process of CDV replication. 相似文献
26.
The present study examined the chemical composition, in vitro antioxidant, anti-hyaluronidase and antifungal activities of essential oils of Melaleuca leucadendron Linn. from Gundih-Central Java, Indonesia in different plant ages of 5, 10 and 15 years old. The Chemical composition of essential oils were analyzed by GC/MS. Twenty-six components were identified, of which 1,8-cineole (49.22–55.04 %), α-terpineol (8.79–10.70 %), d-limonene (5.58–6.39 %), and β-caryophyllene (5.03–7.64 %) were the main compounds in these oils. The antioxidant assay and anti-hyaluronidase assay showed that M. leucadendron leaf oils possess mild antioxidant activity with IC50 between 7.21 and 9.23 mg/ml and anti-hyaluronidase activity with IC50 between 1.94 and 3.03 mg/ml. The antifungal assay showed the effectiveness of these essential oils against Fomitopsis palustris (IC50 0.12–3.16 mg/ml), Trametes versicolor (IC50 0.01–0.06 mg/ml), Cladosporium cladosporioides (IC50 0.03–0.49 mg/ml), and Chaetomium globosum (IC50 0.06–0.15 mg/ml). 相似文献
27.
28.
Particleboards with thickness of 10 mm and densities of 0.6, 0.7 and 0.8 g/cm3 were manufactured from high-moisture particles using urea–formaldehyde resin and the effectiveness of air injection was examined. The temperature in the 0.6 and 0.7 g/cm3 boards was lower with air injection than without during the initial to middle stages of pressing, while the temperature in the 0.8 g/cm3 board remained lower with air injection than without throughout the entire pressing process. Air injection reduced the pressing time required to manufacture the 0.6 and 0.7 g/cm3 boards and also increased the internal bond strength of boards of all densities. In the 0.6 and 0.7 g/cm3 boards, air injection reduced the modulus of rupture (MOR), while in the 0.8 g/cm3 boards, the MOR was similar between those manufactured by injecting and not injecting air. Air injection was also found to be effective for boards of high densities. The effectiveness of the air injection on thick boards was investigated by manufacturing 20-mm-thick boards of 0.7 g/cm3. Without air injection, it was not possible to manufacture the 20-mm-thick boards, even by extended hot pressing, but air injection allowed the boards to be manufactured by pressing for 16 min. Air injection was also shown to be effective for manufacturing thick boards. 相似文献
29.
Particleboards of different densities (0.6, 0.7 and 0.8 g/cm3) and thicknesses (10 and 20 mm) were manufactured from low-moisture particles using an air-injection press. The effects of the air injection on preventing blowout of the boards of different densities and thicknesses were investigated by artificially creating blowout-prone conditions using metal frames. The effects of the air-injection pressure on the board performance were also investigated. 10-mm-thick boards of 0.8 g/cm3 pressed at 170 °C blew out when air was not injected, but were successfully manufactured by injecting air. 10-mm-thick boards at 150 °C showed constant internal bond (IB), regardless of density, but at 170 °C, IB was higher in boards of higher densities. This was likely due to accelerated hardening of the urea–formaldehyde resin at 170 than 150 °C. At both pressing temperatures, low air-injection pressure did not cause blowout and a reduction in board performance. Air injection also prevented the blowout of thick boards of 20 mm and enabled successful manufacture, showing its effectiveness. The IB of the 20-mm-thick board manufactured using the air-injection press exceeded that of 20-mm-thick board manufactured using an ordinary hot press. 相似文献
30.
A wild tetraploid oat Avena maroccana Gdgr. was collected from the 11 populations in the periphery of Rommani and Casablanca geographic groups of Morocco. Genetic
diversity of the species was investigated using six allozyme systems. Allelic frequencies were scored representing eight polymorphic
and five monomorphic loci. Coefficient of gene differentiation (Gst) was 0.3019, which indicated great genetic differentiation. The number of alleles per locus was 2.6154, the percentage of
polymorphic loci was 61.54, and the expected heterozygosity was 0.2462 in all populations. Genetic diversity in A. maroccana was high in comparison to self-pollinated species. In total, nine heterozygotes resulting from outcrossing were found in
the progeny from M1, M3, M4, M22 and M26. The population of M7 had peculiar alleles Pgd–2SS and Pgd-1SS in high frequency. M9 had the lowest level of diversity out of the 11 populations. Geographic and genetic distances between
all the populations were not significantly correlated with each other (r = 0.0996). Cluster analysis showed that two groups, (M1, M22, M2 and M4) and (M3, M23, M8, M5 and M26) were apparently differentiated.
Two populations of the Casablanca group, M7 and M9 were independent from each other, and were separated distinctly from the
other populations. Genetic diversity of the Rommani and Casablanca groups was almost the same in all the parameters. This
was due to the similar man-made habitat such as roadside or rich fertile soil and brown clay soils. The population size of
A. maroccana was small and restricted to the narrow central Morocco with great genetic differentiation so that genetic diversity may be
reflected from the results of genetic drift and outcrossing heterozygote segregation. 相似文献