Publications (126) View all
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Article: Prophylactic effect of Lactobacillus oral vaccine expressing a Japanese cedar pollen allergen.
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ABSTRACT: Lactic acid bacteria (LAB) represent an attractive delivery vehicle for oral allergy vaccine because of their safety as a food microorganism as well as their potent adjuvant activity triggering anti-allergic immune response. Here, we report the generation of recombinant LAB expressing a major Japanese cedar pollen allergen Cry j 1 (Cry j 1-LAB), and their prophylactic effect in vivo. To facilitate heterologous expression, the codon usage in the Cry j 1 gene was optimized for the host LAB strain Lactobacillus plantarum by the recursive PCR-based exhaustive site-directed mutagenesis. Use of the codon-optimized Cry j 1 cDNA and a lactate dehydrogenase gene fusion system led to a successful production of recombinant Cry j 1 in L. plantarum NCL21. We also found that oral vaccination with the Cry j 1-LAB suppressed allergen-specific IgE response and nasal symptoms in a murine model of cedar pollinosis.Journal of Bioscience and Bioengineering 12/2011; 113(4):536-41. · 1.79 Impact Factor -
Article: Production of 5-aminolevulinic acid by Propionibacterium acidipropionici TISTR442.
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ABSTRACT: Propionibacterium acidipropionici TISTR442 produced the highest amount of 5-aminolevulinic acid (ALA) when cultivated in medium supplemented with glycine at 18g/l. ALA production correlated with ALA synthase activity, whereas ALA dehydratase activity was maintained at a low level. ALA yield reached 405mg/l after prolonged cultivation for 1 month.Journal of Bioscience and Bioengineering 12/2010; 111(4):425-8. · 1.79 Impact Factor -
Article: Characterization of the C-terminal truncated form of amylopullulanase from Lactobacillus plantarum L137.
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ABSTRACT: A gene (apuA) encoding amylopullulanase from a starch-hydrolyzing lactic acid bacterium, Lactobacillus plantarum L137, which had been isolated from traditional fermented food made from fish and rice in the Philippines, was found to contain two unique amino acid repeating units in the N- and C-terminal region. The former is a six amino acid sequence (Asp-Ala/Thr-Ala-Asn-Ser-Thr) repeated 39 times, and the latter is a three amino acid sequence (Gln-Pro-Thr) repeated 50 times. To clarify the role of these repeating units, a truncated apuA in the C-terminal region was constructed and expressed in L. plantarum NCL21, which is the ApuA- derivative of strain L137. The recombinant truncated amylopullulanase (ApuADelta), which lacks the 24 kDa of the C-terminal repeat region, was purified and characterized, and compared with wild-type amylopullulanase (ApuA). The enzyme production and specific activity of ApuADelta were higher than those of ApuA. The two enzymes, ApuA and ApuADelta, showed similar pH (4.0-4.5) and temperature (40-45 degrees C) optima. However, the activity of ApuADelta was more stable in the pH and temperature than that of ApuA. The catalytic efficiencies of ApuADelta toward soluble starch, pullulan and amylose were higher than those of ApuA, although their substrate specificities towards saccharides were similar. From these results, we conclude that the C-terminal repeating region of ApuA is negatively involved in the stability of amylopullulanase and binding of substrates. Thus, the truncated amylopullulanase is more useful in processing of amylose and pullulan.Journal of Bioscience and Bioengineering 03/2009; 107(2):124-9. · 1.79 Impact Factor -
Article: Gibberellin controls the nodulation signaling pathway in Lotus japonicus.
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ABSTRACT: Root nodule formation is regulated by several plant hormones, but the details of the regulation of the nodulation signaling pathway are largely unknown. In this study, the role of gibberellin (GA) in the control of root nodule symbiosis was investigated at the physiological and genetic levels in Lotus japonicus. Exogenous application of biologically active GA, GA(3), inhibited the formation of infection threads and nodules, which was counteracted by the application of a biosynthesis inhibitor of GA, Uniconazole P. Nod factor-induced root hair deformation was severely blocked in the presence of GA, which was phenocopied by nsp2 mutants. The number of spontaneous nodules triggered by the gain-of-function mutation of calcium/calmodulin-dependent kinase (CCaMK) or the lotus histidine kinase 1 (LHK1) was decreased upon the addition of GA; moreover, the overexpression of the gain-of-function mutation of L. japonicus, SLEEPY1, a positive regulator of GA signaling, resulted in a reduced nodule number, without other aspects of root development being affected. These results indicate that higher GA signaling levels specifically inhibit the nodulation signaling pathway. Nod factor-dependent induction of NSP2 and NIN was inhibited by exogenous GA. Furthermore, the cytokinin-dependent induction of NIN was suppressed by GA. From these results, we conclude that GA inhibits the nodulation signaling pathway downstream of cytokinin, possibly at NSP2, which is required for Nod factor-dependent NIN expression. These results clarify the roles of GA in the nodulation signaling pathway, and in relation to the cytokinin signaling pathway for nodulation in L. japonicus.The Plant Journal 01/2009; 58(2):183-94. · 6.16 Impact Factor -
Article: CYCLOPS, a mediator of symbiotic intracellular accommodation.
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ABSTRACT: The initiation of intracellular infection of legume roots by symbiotic rhizobia bacteria and arbuscular mycorrhiza (AM) fungi is preceded by the induction of calcium signatures in and around the nucleus of root epidermal cells. Although a calcium and calmodulin-dependent kinase (CCaMK) is a key mediator of symbiotic root responses, the decoding of the calcium signal and the molecular events downstream are only poorly understood. Here, we characterize Lotus japonicus cyclops mutants on which microbial infection was severely inhibited. In contrast, nodule organogenesis was initiated in response to rhizobia, but arrested prematurely. This arrest was overcome when a deregulated CCaMK mutant version was introduced into cyclops mutants, conferring the development of full-sized, spontaneous nodules. Because cyclops mutants block symbiotic infection but are competent for nodule development, they reveal a bifurcation of signal transduction downstream of CCaMK. We identified CYCLOPS by positional cloning. CYCLOPS carries a functional nuclear localization signal and a predicted coiled-coil domain. We observed colocalization and physical interaction between CCaMK and CYCLOPS in plant and yeast cell nuclei in the absence of symbiotic stimulation. Importantly, CYCLOPS is a phosphorylation substrate of CCaMK in vitro. Cyclops mutants of rice were impaired in AM, and rice CYCLOPS could restore symbiosis in Lotus cyclops mutants, indicating a functional conservation across angiosperms. Our results suggest that CYCLOPS forms an ancient, preassembled signal transduction complex with CCaMK that is specifically required for infection, whereas organogenesis likely requires additional yet-to-be identified CCaMK interactors or substrates.Proceedings of the National Academy of Sciences 01/2009; 105(51):20540-5. · 9.68 Impact Factor
