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981.
Osmotin or osmotin-like protein, a PR-5 family member, is differentially induced in plants by abiotic and biotic stresses. Here, we demonstrate that the pepper (Capsicum annuum) osmotin-like protein 1 gene, CaOSM1, was required for the defense and hypersensitive cell death response and oxidative burst signaling during Xanthomonas campestris pv. vesicatoria (Xcv) infection. CaOSM1 protein was localized to the plasma membrane in leaf cells of Nicotiana benthamiana. Agrobacterium-mediated transient expression of CaOSM1 in pepper distinctly induced the hypersensitive cell death response and H2O2 accumulation. Knock-down of CaOSM1 in pepper by virus-induced gene silencing increased the susceptibility to Xcv infection, which was accompanied by attenuation of the cell death response and decreased accumulation of H2O2. CaOSM1 overexpression in transgenic Arabidopsis conferred reduced susceptibility and accelerated cell death response and H2O2 accumulation to infection by Pseudomonas syringe pv. tomato and Hyaloperonospora arabidopsidis. Together, these results suggest that CaOSM1 is involved in cell death and oxidative burst responses during plant defense against microbial pathogens. 相似文献
982.
983.
In‐Jin Yoon 《Ethnic and racial studies》2013,36(2):315-335
The growth of Korean immigrant entrepreneurship in Chicago is a product of three interacting factors: employment opportunities in the general labour market, resource mobilization, and business opportunity structures. Because of their language barrier and less transferable education and occupational skills in the American labour market, many Korean immigrants could not find white‐collar occupations for which they had been trained. Disadvantaged, but still strongly motivated for upward economic mobility in the United States, many of them became self‐employed business owners. Korean immigrants’ middle‐class backgrounds and their stable family structures and strong family ties helped them to realize their goal of business ownership. In addition, social networks based on kinship, friendship, church membership, and school ties provided prospective business owners with financial assistance, training, business advice, and information about business opportunities. The first business opportunities for Korean immigrants of Chicago opened in Korean ethnic markets and non‐ethnic minority markets almost simultaneously in the early 1970s. While the demand of Koreans for their cultural products created an economic niche for Korean‐oriented businesses, the export‐import trade linkage between South Korea and the United States has paved the way for the entrance of Korean businesses into minority areas. Because of different economic niches, the two types of Korean businesses developed independently. The interethnic succession of residence, which had occurred in the late 1960s and early 1970s also produced vacated business opportunities in Koreatown and black neighbourhoods, enabling Korean immigrants to enter these areas without great resistance from local businesses. After Korean immigrants had accumulated capital and experience in Korean ethnic markets and minority markets, they advanced into more capital‐intensive businesses like garment manufacturing. Korean immigrant professionals began to enter the Korean ethnic economy in the early 1980s when the foundation of the Korean ethnic economy was already established. 相似文献
984.
985.
986.
Suman Kundu Talat Roome Ashish Bhattacharjee Kevin A. Carnevale Valentin P. Yakubenko Renliang Zhang Sung Hee Hwang Bruce D. Hammock Martha K. Cathcart 《Journal of lipid research》2013,54(2):436-447
Monocyte chemoattractant protein-1 (MCP-1)-induced monocyte chemotaxis is a major event in inflammatory disease. Our prior studies have demonstrated that MCP-1-dependent chemotaxis requires release of arachidonic acid (AA) by activated cytosolic phospholipase A2 (cPLA2). Here we investigated the involvement of AA metabolites in chemotaxis. Neither cyclooxygenase nor lipoxygenase pathways were required, whereas pharmacologic inhibitors of both the cytochrome-P450 (CYP) and the soluble epoxide hydrolase (sEH) pathways blocked monocyte chemotaxis to MCP-1. To verify specificity, we demonstrated that the CYP and sEH products epoxyeiscosatrienoic acids (EETs) and dihydroxyeicosatrienoic acids (DHETs), respectively, restored chemotaxis in the presence of the inhibitors, indicating that sEH-derived products are essential for MCP-1-driven chemotaxis. Importantly, DHETs also rescued chemotaxis in cPLA2-deficient monocytes and monocytes with blocked Erk1/2 activity, because Erk controls cPLA2 activation. The in vitro findings regarding the involvement of CYP/sEH pathways were further validated in vivo using two complementary approaches measuring MCP-1-dependent chemotaxis in mice. These observations reveal the importance of sEH in MCP-1-regulated monocyte chemotaxis and may explain the observed therapeutic value of sEH inhibitors in treatment of inflammatory diseases, cardiovascular diseases, pain, and even carcinogenesis. Their effectiveness, often attributed to increasing EET levels, is probably influenced by the impairment of DHET formation and inhibition of chemotaxis. 相似文献
987.
Ching-Hung Lee Yen-Wei Chen Yun-Tzu Huang Yih-Jiuan Pan Chien-Hsien Lee Shih-Ming Lin Lin-Kun Huang Yueh-Yu Lo Yu-Fen Huang Yu-Di Hsu Shih-Chung Yen Jenn-Kang Hwang Rong-Long Pan 《The Journal of membrane biology》2013,246(12):959-966
H+-translocating pyrophosphatase (H+-PPase, EC 3.6.1.1) plays an important role in acidifying vacuoles by transporting protons across membranes at the expense of pyrophosphate (PPi) hydrolysis. Vigna radiata H+-PPase (VrH+-PPase) contains 16 transmembrane helices (TMs). The hydrophobicity of TM3 is relatively lower than that of most other TMs, and the amino acids in this TM are highly conserved in plants. Furthermore, TM5 and -6, which are the core TMs involving in H+-PPase functions, are near TM3. It is thus proposed that TM3 is associated with H+-PPase activity. To address this possibility, site-directed mutagenesis was applied in this investigation to determine the role of TM3 in VrH+-PPase. Upon alanine/serine substitution, T138 and S142, whose side chains face toward the center TMs, were found to be involved in efficient proton transport. G149/S153 and G160/A164 pairs at the crucial termini of the two GxxxG-like motifs are indispensable in maintaining enzymatic activities and conformational stability. Moreover, stability in the vicinity surrounding G149 is pivotal for efficient expression. S153, M161 and A164 are critical for the K+-mediated stimulation of H+-PPase. Taken together, our results demonstrate that TM3 plays essential roles in PPi hydrolysis, proton transport, expression, and K+ stimulation of H+-PPase. 相似文献
988.
Natalia Jiménez José Antonio Curiel Inés Reverón Blanca de las Rivas Rosario Mu?oz 《Applied and environmental microbiology》2013,79(14):4253-4263
Lactobacillus plantarum is a lactic acid bacterium able to degrade tannins by the subsequent action of tannase and gallate decarboxylase enzymes. The gene encoding tannase had previously been identified, whereas the gene encoding gallate decarboxylase is unknown. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of gallic-acid induced L. plantarum extracts showed a 54-kDa protein which was absent in the uninduced cells. This protein was identified as Lp_2945, putatively annotated UbiD. Homology searches identified ubiD-like genes located within three-gene operons which encoded the three subunits of nonoxidative aromatic acid decarboxylases. L. plantarum is the only bacterium in which the lpdC (lp_2945) gene and the lpdB and lpdD (lp_0271 and lp_0272) genes are separated in the chromosome. Combination of extracts from recombinant Escherichia coli cells expressing the lpdB, lpdC, and lpdC genes demonstrated that LpdC is the only protein required to yield gallate decarboxylase activity. However, the disruption of these genes in L. plantarum revealed that the lpdB and lpdC gene products are essential for gallate decarboxylase activity. Similar to L. plantarum tannase, which exhibited activity only in esters derived from gallic and protocatechuic acids, purified His6-LpdC protein from E. coli showed decarboxylase activity against gallic and protocatechuic acids. In contrast to the tannase activity, gallate decarboxylase activity is widely present among lactic acid bacteria. This study constitutes the first genetic characterization of a gallate decarboxylase enzyme and provides new insights into the role of the different subunits of bacterial nonoxidative aromatic acid decarboxylases. 相似文献
989.
Ismail Bezirganoglu Shaw-Yhi Hwang Tony J. Fang Jei-Fu Shaw 《Plant Cell, Tissue and Organ Culture》2013,112(2):227-237
The oriental melon (Cucumis melo L. var. makuwa cv. ‘Silver Light’) is an important fruit crop in the tropical and subtropical regions. However, oriental melon production is severely decreased by fungal diseases. In this study, antifungal protein (AFP) and chitinase (CHI) fusion genes were introduced into oriental melons to control fungal diseases caused by Rhizoctonia solani and Fusarium oxysporum. Transformation of oriental melon (Cucumis melo L. var. makuwa cv. ‘Silver Light’) with Agrobacterium tumefaciens strain LBA4404 containing antifungal protein (AFP) and chitinase (CHI) fusion genes under the control of the cauliflower mosaic virus (CaMV) 35S promoter and neomycin phosphotransferase (nptII) gene as a selectable marker was performed. Cotyledon explants of oriental melon were inoculated by Agrobacterium suspensions with pBI121–AFP–CHI and cultured in a regeneration medium. After regeneration, genomic DNA polymerase chain reaction (PCR) was conducted to confirm the presence of putative transgenic shoots. Southern blot analysis confirmed that the AFP–CHI fusion gene was incorporated into the genomic DNA of the PCR-positive lines. RT-PCR analysis showed that the AFP–CHI fusion gene was expressed in the individual transgenic lines. Western blot analysis revealed the accumulation of CHI protein in leaves. A segregation analysis of the T1 generation confirmed the inheritance of the transgene. Our results demonstrated that the AFP–CHI fusion gene was effective in protecting the transgenic melon plants against fungal disease caused by Rhizoctonia solani and Fusarium oxysporum. 相似文献
990.
Andrew L. Robison Todd M. Scanlon Bernard J. Cosby James R. Webb James N. Galloway 《Biogeochemistry》2013,113(1-3):119-136
Micro-organisms are vital for the functioning of all food webs and are the major drivers of the global biogeochemical cycles. The microbial community compositions and physicochemical conditions of the different water masses in the North Sea, a biologically productive sea on the northwestern European continental shelf, were studied during two summer cruises, in order to provide detailed baseline data for this region and examine its microbial biogeography. For each cruise the stations were clustered according to their physicochemical characteristics and their microbial community composition. The largest cluster, which covered most of the central and northern North Sea, consisted of stations that were characterized by a thermally stratified water column and had low chlorophyll a autofluorescence and generally low microbial abundances. The second main cluster contained stations that were dominated by picoeukaryotes and showed the influence of influxes of North Atlantic water via the English Channel and south of the Shetland Islands. The third main cluster was formed by stations that were dominated by cyanobacteria and nanoeukaryotes in the reduced salinity Norwegian Coastal and Skagerrak waters, while the fourth cluster represented the German Bight, a region with strong riverine input, high nutrient concentrations, and consequently high heterotrophic bacterial and viral abundances. Despite the complex and dynamic hydrographic nature of the North Sea, the consistent distinctions in microbiology between these different hydrographic regions during both cruises illustrate the strong links between the microbial community and its environment, as well as the possibility to use microorganisms for long-term monitoring of environmental change. 相似文献