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991.
Kim HL Shin E Kim HM Go H Roh J Bae J Lee K 《Journal of microbiology and biotechnology》2007,17(10):1708-1711
The Streptomyces coelicolor M145 genome harbors six copies of divergent rRNA operons that differ at ~0.2% and ~0.6% of the nucleotide positions in small subunit (SSU) and large subunit (LSU) rRNA genes, respectively. When these rRNA genes are expressed, a single cell may harbor three different kinds of SSU rRNA and five kinds of LSU rRNA. Primer extension analyses revealed that all of the heterogeneous rRNA molecules are expressed and assembled into ribosomes. This finding and the maintenance of the intragenomic variability of rRNA operons imply the existence of functional divergence of rRNA species in this developmentally complex microorganism. 相似文献
992.
Bae EA Min SW Lee B Kim NJ Baek NI Han EJ Chung HG Kim DH 《Journal of microbiology and biotechnology》2007,17(9):1554-1557
Artemisia princeps Pampanini (AP) was fermented with Bifidobacterium infantis K-525 and its antiasthmic effect investigated. AP and fermented AP (FAP) reduced the IgE level in the blood of ovalbumin-induced asthmic mice. Moreover, FAP reduced the IgE, proinflammatory cytokine IL-6, and IL-4 levels in the trachea, as well as in the lung of the experimental asthmic mice, whereas AP only reduced the IgE and IL-6 levels in the lungs. Nonetheless, AP and FAP both inhibited the mRNA expression of IL-6 and TNF-alpha in IgE-induced RBL-2H3 cells. The in vivo antiasthmic effect of FAP was more potent than that of AP. Therefore, these findings suggest that the enhanced antiasthmic effect of AP after bifidus fermentation was possibly due to the regulation of the proinflammatory cytokine biosynthesis of IL-6 and TNF-alpha. 相似文献
993.
Lim WY Baik KS Chun J Lee KH Jung WJ Bae KS 《Journal of microbiology and biotechnology》2007,17(3):468-473
White rot fungi, Phanerochaete chrysosporium and Phanerochaete sordida, have been mostly studied in a variety of industrial processes like biopulping and pulp bleaching as well as in bioremediation. Whereas P. sordida is widely distributed in the North Temperate Zone, P. chrysosporium is reported in the restricted area and hundreds of reports have been described from a few strains of P. chrysosporium, which are deposited at various fungal collections in the world. The isolates of two species are not easily discriminated because of their morphological and molecular similarity. Through the ITS sequence analyses, a region containing substantial genetic variation between the two species was identified. PCR amplification using two specific primers was successfully used to differentiate P. chrysosporium from P. sordida. These results were supported by cultural studies. The growth rates at 37 degrees C on PDA, MEA, and Cza and the microscopic features of conidia on PDA and YMA were also very useful to differentiate those two species. 相似文献
994.
The mechanisms by which telomeres are distinguished from DNA double-strand breaks are poorly understood. Here we have defined the minimal requirements for the protection of telomeric DNA ends from nonhomologous end-joining (NHEJ). Neither long, single-stranded overhangs nor t loop formation is essential to prevent NHEJ-mediated ligation of telomeric ends in vitro. Instead, a tandem array of 12 telomeric repeats is sufficient to impede illegitimate repair in a highly directional manner at nearby DNA ends. The polarity of end protection is consistent with the orientation of naturally occurring telomeres and is well suited to minimize interference between chromosome capping and the repair of DNA double-strand breaks in subtelomeric sequences. Biochemical fractionation and reconstitution revealed that telomere protection is mediated by a RAP1/TRF2 complex, providing evidence for a direct role for human RAP1 in the protection of telomeric DNA from NHEJ. 相似文献
995.
Jeong-Won Bae So-Hye Kim Dae-Hyun Kim Jae Jung Ha Jun Koo Yi Seongsoo Hwang Buom-Yong Ryu Myung-Geol Pang Woo-Sung Kwon 《Reproductive biology》2019,19(4):356-362
Ras-related protein Rab (Rab) proteins, member of Ras superfamily of monomeric G proteins, are well known key regulators of intracellular vesicular transport. Recently, it has been reported that Rab 2A and 3A are related to acrosomal exocytosis in spermatozoa and Rab 2A can be used to fertility-related biomarker in male. However, the role and mechanism of Rab proteins in spermatozoa has not been fully understood yet. Therefore, the study to analyze the expression and location of various Rab proteins in spermatozoa is required to understand the role and mechanism of Rab proteins in spermatozoa. In present study, to analyze the expression level and location of various Rab proteins (Rab 2A, Rab3A, Rab4, Rab5, Rab8A, Rab9, Rab11, Rab14, Rab25, Rab27A, and Rab34) and Rab protein regulators (RabGAP, RabGDI, RabGEF) in spermatozoa following capacitation, immunofluorescence and western blot analysis were performed. All of 11 Rab proteins were expressed in acrosomal region and tail of spermatozoa. Furthermore, all Rab proteins and Rab protein regulators, except RabGAP, have decreased expression patterns after capacitation. Taken together, Rab proteins were located in sperm head and tail. In addition, expression patterns of Rab proteins in spermatozoa were altered following capacitation. Therefore, our results suggested that Rab proteins may be key proteins related with capacitation as well as playing important role with uniquely activation pathway for male fertility. 相似文献
996.
Perioperative brain ischemia and stroke are leading causes of morbidity and mortality. Brief hypoxic preconditioning is known to have protective effects against hypoxic-ischemic insult in the brain. Current studies on the neuroprotective effects of ischemic preconditioning are based on histologic findings and biomarker changes. However, studies regarding effects on memory are rare. To precondition zebrafish to hypoxia, they were exposed to a dissolved oxygen (DO) concentration of 1.0?±?0.5?mg/L in water for 30?s. The hypoxic zebrafish were then exposed to 1.0?±?0.5?mg/L DO until the third stage of hypoxia, for 10 min?±?30?s. Zebrafish were assessed for memory retention after the hypoxic event. Learning and memory were tested using the T-maze, which evaluates memory based on whether or not zebrafish moves to the correct target compartment. In the hypoxic preconditioning group, infarct size was reduced compared with the hypoxic-only treated zebrafish group; memory was maintained to a degree similar to that in the hypoxia-untreated group. The hypoxic-only group showed significant memory impairments. In this study, we used a hypoxic zebrafish model and assessed the effects of ischemic preconditioning not only on histological damages but also on brain function, especially memory. This study demonstrated that a brief hypoxic event has protective effects in hypoxic brain damage and helped maintain memory in zebrafish. In addition, our findings suggest that the zebrafish model is useful in rapidly assessing the effects of ischemic preconditioning on memory. 相似文献
997.
Kyung June Yim In-Tae Cha Hae-Won Lee Hye Seon Song Kil-Nam Kim Sung-Jae Lee Young-Do Nam Dong-Wook Hyun Jin-Woo Bae Sung-Keun Rhee Myung-Ji Seo Jong-Soon Choi Hak-Jong Choi Seong Woon Roh Daekyung Kim 《Antonie van Leeuwenhoek》2014,105(3):603-612
A novel, red-pigmented, pleomorphic and short rod-shaped haloarchaeon, designated B8T, was isolated from a salt-fermented seafood. Strain B8T was found to be able to grow at 20–45 °C, in the presence of 15–30 % (w/v) NaCl and at pH 7.0–9.0. The optimum requirements were found to be a temperature range of 35–40 °C, pH 8.0 and the presence of 25 % NaCl. The cells of strain B8T were observed to be Gram-staining negative and lysed in distilled water. Anaerobic growth did not occur in the presence of nitrate, l-arginine, dimethyl sulfoxide or trimethylamine N-oxide. The catalase and oxidase activities were found to be positive and nitrate was reduced in aerobic conditions. Tween 20, 40 and 80 were found to be hydrolyzed, whereas casein, gelatin and starch were not hydrolyzed. Indole or H2S was not formed and urease activity was not detected. A phylogenetic analysis based on the 16S rRNA gene sequences indicated that strain B8T is most closely related to members of the genus Halorubrum in the family Halobacteriaceae. Strain B8T was found to have three 16S rRNA genes, rrnA, rrnB and rrnC; similarities between the 16S rRNA gene sequences are 99.0–99.8 %. Strain B8T shared 99.0 % 16S rRNA gene sequence similarity with Halorubrum (Hrr.) lipolyticum JCM 13559T and Hrr. saccharovorum DSM 1137T, 98.8 % with Hrr. kocurii JCM 14978T, 98.3 % with Hrr. lacusprofundi DSM 5036T, 98.0 % with Hrr. arcis JCM 13916T, 97.7 % with Hrr. aidingense JCM 13560T and 97.0 % with Hrr. aquaticum JCM 14031T, as well as 93.7–96.5 % with other type strains in the genus Halorubrum. The RNA polymerase subunit B′ gene sequence similarity of strain B8T with Hrr. kocurii JCM 14978T is 97.2 % and lower with other members of the genus Halorubrum. DNA–DNA hybridization experiments showed that strain B8T shared equal or lower than 50 % relatedness with reference species in the genus Halorubrum. The genomic DNA G+C content of strain B8T was determined to be 64.6 mol%. The major isoprenoid quinone of strain B8T was identified as menaquinone-8 and the major polar lipids as phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, phosphatidylglycerol sulfate, sulfated mannosyl glucosyl diether and an unidentified phospholipid. Based on this polyphasic taxonomic study, strain B8T is considered to represent a new species in the genus Halorubrum, for which the name Hrr. halophilum sp. nov. is proposed. The type strain is B8T (=JCM 18963T = CECT 8278T). 相似文献
998.
Kyung Yong Lee June Sung Bae Gwang Su Kim Deog Su Hwang 《Biochemical and biophysical research communications》2014
Phosphorylation of Thr116 and Thr226 on Orc2, one of the six subunits of the origin recognition complex (ORC), by cyclin A/CDK2 during S phase leads to the dissociation of Orc2, Orc3, Orc4, and Orc5 subunits (Orc2-5) from human chromatin and replication origins. The phosphorylated Orc2 becomes dephosphorylated in the late M phase of the cell cycle. Here we show that protein phosphatase 1 (PP1) dephosphorylates Orc2. Dephosphorylation of Orc2 was accompanied by associating the dissociated Orc subunits with chromatin. Inhibitors of PP1 preferentially inhibited the dephosphorylation of Orc2. The overexpression of the α, β and γ PP1 isoforms decreased the amount of phosphorylated Orc2, and the depletion of these isoforms by RNA interference increased the amount of phosphorylated Orc2. These results suggest that PP1 dephosphorylates Orc2 to promote the binding of ORC to chromatin. 相似文献
999.
Eunbi Ko Hyun Choi Borim Kim Minsun Kim Kkot-Nara Park Il-Hong Bae Young Kwan Sung Tae Ryong Lee Dong Wook Shin Yun Soo Bae 《The Journal of biological chemistry》2014,289(42):28835-28845
Testosterone is an endocrine hormone with functions in reproductive organs, anabolic events, and skin homeostasis. We report here that GPRC6A serves as a sensor and mediator of the rapid action of testosterone in epidermal keratinocytes. The silencing of GPRC6A inhibited testosterone-induced intracellular calcium ([Ca2+]i) mobilization and H2O2 generation. These results indicated that a testosterone-GPRC6A complex is required for activation of Gq protein, IP3 generation, and [Ca2+]i mobilization, leading to Duox1 activation. H2O2 generation by testosterone stimulated the apoptosis of keratinocytes through the activation of caspase-3. The application of testosterone into three-dimensional skin equivalents increased the apoptosis of keratinocytes between the granular and stratified corneum layers. These results support an understanding of the molecular mechanism of testosterone-dependent apoptosis in which testosterone stimulates H2O2 generation through the activation of Duox1. 相似文献
1000.
Sunyoung Park Sang Doo Kim Ha Young Lee Dobeen Hwang Joon Seong Park Yoe-Sik Bae Junho Chung 《Biochemical and biophysical research communications》2014
Although many peptides have therapeutic effects against diverse disease, their short half-lives in vivo hurdle their application as drug candidates. To extend the short elimination half-lives of therapeutic peptides, we developed a novel delivery platform for therapeutic peptides using an anti-hapten antibody and its corresponding hapten. We selected cotinine because it is non-toxic, has a well-studied metabolism, and is physiologically absent. We conjugated WKYMVm-NH2, an anti-sepsis therapeutic peptide, to cotinine and showed that the conjugated peptide in complex with an anti-cotinine antibody has a significantly improved in vivo half-life while retaining its therapeutic efficacy. We suggest that this novel delivery platform for therapeutic peptides will be very useful to develop effective peptide therapeutics. 相似文献