Taxonomy of the Genus Zeadolopus Broun (Coleoptera: Leiodidae: Leiodinae) in Korea

A taxonomic study of the genus Zeadolopus Broun in Korea is presented. Two species, Zeadolopus chaosicus Daffner and Z. japonica (Champion), are recognized and the latter is recorded for the first time in Korea. A key, diagnoses, and illustrations of diagnostic characters are provided.     

Improved expression of porcine epidemic diarrhea antigen by fusion with cholera toxin B subunit and chloroplast transformation in Nicotiana tabacum

The porcine epidemic diarrhea virus (PEDV) belongs to the coronavirus family, which causes acute diarrhea in pigs with higher mortality in piglets less than 2 weeks old. The PEDV is one of the major concerns of the pig industry around the world, including Asian countries and Noth America since first identified in Europe. Currently, there is no PEDV licensed vaccine to effectively prevent this disease. This study was performed for the development of a mucosal PEDV vaccine and B subunit of cholera toxin (CTB) as a carrier was employed to surpass the tolerogenic nature of GALT and induce potent immune responses against the target antigen fused to CTB. An epitope (S1D) alone or conjugated with CTB was constructed into the tobacco chloroplasts expression vector which is controlled under the chloroplast rRNA operon promoter with T7g10 5′ UTR and the psbA 3′UTR as a terminator. The homoplastomic lines were obtained by third round screening via organogenesis from the leaf tissues which were verified by PCR with antigen and chloroplast specific primers and then confirmed by Southern blot analysis. While the expression level of the S1D alone as detected by Western blotting was approximately 0.07% of total soluble protein, the CTB-S1D fusion protein was expressed up to 1.4%. The fusion protein showed binding to the intestinal membrane GM1-ganglioside receptor, demonstrating its functionality. The result shows that the highest expression of S1D could be achieved by fusion with a stable CTB protein and chloroplast transformation. Furthermore, the CTB-S1D expressed in chloroplasts of Nicotiana tabacum cv. Maryland could be assembled to pentameric form which increases the possibility to develop a mucosal vaccine against PEDV.

     

Expression of non-toxic mutant of Escherichia coli heat-labile enterotoxin in tobacco chloroplasts

Chloroplast transformation systems offer unique advantages in biotechnology, including high level of foreign gene expression, maternal inheritance, and polycistronic expression. We studied chloroplast expression of LTK63 (change Ser-->Lys at position 63 in the A subunit) which is the mutant of Escherichia coli heat-labile toxin. LTK63 is devoid of any toxic activity, but still retains its mucosal adjuvanticity. The LTK63 was cloned into chloroplast targeting vector and transformed to tobacco chloroplasts by particle bombardment. PCR and Southern blot analyses confirmed stable homologous recombination of the LTK63 gene into the chloroplast genome. The amount of LTK63 protein detected in tobacco chloroplasts was approximately 3.7% of the total soluble protein. The GM1-ganglioside binding assay confirmed that chloroplast-synthesized LTB of LTK63 binds to the intestinal membrane GM1-ganglioside receptor. Thus, the expression of LTK63 in chloroplasts provides a potential route toward the development of a plant-based edible vaccine for high expression system and environmentally friendly approach.     

Anti-tumor activity of the farnesyl-protein transferase inhibitors arteminolides, isolated from Artemisa

Members of the Artemisia genus are important medicinal plants found throughout the world. Arteminolides A-D (1-4), isolated from the aerial parts of Artemisia, have an inhibitory activity on farnesyl-protein transferase (FPTase; EC 2.5.1.29) in in vitro assay. This study was carried out with the purpose of validating anti-tumor effects of the compounds in human tumor cells and mouse xenograft model. The arteminolides inhibited tumor cell growth in a dose-dependent manner. Furthermore, arteminolide C (3) blocked in vivo growth of human colon and lung tumor xenograft without the loss of body weight in nude mice.     

Phosphorylation of threonine 10 on CKBBP1/SAG/ROC2/Rbx2 by protein kinase CKII promotes the degradation of IkappaBalpha and p27Kip1

In eukaryotic cells, protein kinase CKII is required for progression through the cell division cycle. We recently reported that CKBBP1/SAG/ROC2/Rbx2 associates with the beta-subunit of CKII and is phosphorylated by purified CKII in the presence of ATP in vitro. In this report, we demonstrate that CKBBP1 is efficiently phosphorylated in vitro by purified CKII in the presence of GTP and by heparin-sensitive protein kinase in HeLa cell extract. Mutational analysis indicates that CKII phosphorylates threonine at residue 10 within CKBBP1. Furthermore, CKBBP1 is phosphorylated in vivo and threonine to alanine mutation at residue 10 abrogates the phosphorylation of CKBBP1 observed in vivo, indicating that CKII is a major kinase that is responsible for in vivo phosphorylation of CKBBP1. As compared with the wild-type CKBBP1 or CKBBP1T10E (in which threonine 10 is replaced by glutamate), overexpression of nonphosphorylatable CKBBP1 (CKBBP1T10A) results in accumulation of IkappaBalpha and p27Kip1. Experiments using proteasome inhibitor MG132 and CKII inhibitor 5,6-dichloro-1-beta-d-ribofuranosylbenzimidazole suggest that the accumulation of IkappaBalpha and p27Kip1 results primarily from the reduction of proteasomal degradation in cells expressing CKBBP1T10A, and that CKII-mediated CKBBP1 phosphorylation is required for efficient degradation of IkappaBalpha and p27Kip1. Overexpression of CKBBP1T10A in HeLa cells suppresses cell proliferation and causes accumulation of G1/G0 peak of the cell cycle. Taken together, our results indicate that CKII may control IkappaBalpha and p27Kip1 degradation and thereby G1/S phase transition through the phosphorylation of threonine 10 within CKBBP1.     

Sulfuretin attenuates allergic airway inflammation in mice

Sulfuretin is one of the main flavonoids produced by Rhus verniciflua, which is reported to inhibit the inflammatory response by suppressing the NF-κB pathway. Because NF-κB activation plays a pivotal role in the pathogenesis of allergic airway inflammation, we here examined the effect of sulfuretin on an ovalbumin-induced airway inflammation model in mice. We isolated sulfuretin from R. verniciflua. Sulfuretin was delivered intraperitoneally after the last ovalbumin challenge. Airway hyper-responsiveness, cytokines, mucin, and eosinophilic infiltration were analyzed in bronchoalveolar lavage fluid and lung tissue. A single administration of sulfuretin reduced airway inflammatory cell recruitment and peribronchiolar inflammation and suppressed the production of various cytokines in bronchoalveolar fluid. In addition, sulfuretin suppressed mucin production and prevented the development of airway hyper-responsiveness. The protective effect of sulfuretin was mediated by the inhibition of the NF-κB signaling pathway. Our results suggest that sulfuretin may have therapeutic potential for the treatment of allergic airway inflammation.