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971.
Pterin-4alpha-carbinolamine dehydratase (PCD) is a key enzyme in the regeneration pathway of tetrahydrobiopterin. Previously, we isolated and reported the Drosophila melanogaster gene encoding PCD. In the present study, we isolated and characterized the Drosophila virilis gene encoding PCD. The Drosophila virilis PCD gene has two introns and an open reading frame to encode a protein of 101 amino acids. The amino acid sequence of Drosophila virilis PCD shows a 83% homology to that of the Drosophila melanogaster PCD protein. From the alignment of the nucleotide sequence in the 5'-flanking region of the Drosophila melanogaster and Drosophila virilis PCD genes, we found four conserved sequences. Using a transient transfection assay, we showed that one of the conserved sequences (-127 to approximately -115) is critical for expression, also the minimal promoter region between -127 and +51 is necessary for the efficient expression of Drosophila melanogaster PCD. 相似文献
972.
Doo Hyun Chung Kyeong Cheon Jung Weon Seo Park Im-Soon Lee Weon Jin Choi Chong-Jae Kim Seong Hoe Park Youngmee Bae 《Molecules and cells》2001,10(6):642-646
To induce proper immune responses, T lymphocytes require two types of stimuli, antigen-specific and costimulatory signals. Among costimulatory molecules, CD28-engagement promotes the survival and proliferation of both naive and memory T cells. In addition, it is now believed that Fas may play a role in T cell activation in the human system. It is, however, controversial whether Fas can act as a costimulatory signal in the murine system. Thus, we investigated fundamental differences in the capacity to induce proliferation of T cells between Fas and CD28 in mice. Fas-mediated T cell proliferation was observed only with a full mitogenic dose of anti-CD3 antibodies, whereas CD28 engagement was able to enhance T cell proliferation in the presence of a suboptimal level of anti-CD3 antibody. Furthermore, Fas-engaged T cells showed faster response in the upregulation of CD25 and CD69 expression than CD28-engaged ones. Here, we report that Fas might play a role in mature T cell activation in the mouse system through a different mechanism from that in CD28 costimulation. 相似文献
973.
974.
Chul Soo Shin Min Seon Hong Hang-Cheol Shin Jeewon Lee 《Biotechnology and Bioprocess Engineering》2001,6(4):301-305
The co-expression of theargU gene in a double-vector expression system of recombinantEscherichia coli BL21(DE3)[pET-IFN2a+pAC-argU] significantly enhanced the production level of recombinant human interferon-α2a (rhIFN-α2a)
in high cell density cultures compared to a recombinantE coli culture containing only the single expression vector, pET-IFN2a. The dry cell mass concentration increased to almost 100
g/L, and more than 4 g/L of rhIFN-α2a was accumulated in the culture broth. Evidently, the synthesis of rhIFN-α2a was strongly
dependent on the pre-induction growth rate and more efficient at a higher specific growth rate. The additional supply of tRNAArg(AGG/AGA) enhanced the expression level of the rhIFN-α2a gene in the early stage of the post-induction phase, yet thereafter the specific
production rate of rhIFN-α2a rapidly decreased due to severe segregational instability of plasmid vector pET-IFN2a. It would
appear that the plasmid instability, which only occurred to pET-IFN2a in the double vector system, was related to the effect
of translational stress due to the overexpression of rhIFN-α2a. 相似文献
975.
A new bitterling, Rhodeus pseudosericeus sp. nov., is described on the basis of 31 specimens from five localities included in the Namhan River system, South Korea.
The new species is distinguished from other Rhodeus species by the following combination of characters: branched dorsal fin rays 9–10 (mode 9); branched anal fin rays 9–11 (mode
10); longest simple ray of dorsal fin strong and stiff, distally segmented; pelvic fin rays i, 6–7; iris of males blackish;
dorsal and anal fins of males grayish in breeding season; karyotype with 2n = 48 (8m + 20sm + 20st). Rhodeus pseudosericeus sp. nov. is similar to Rhodeus sericeus sericeus in the number of pelvic fin and branched dorsal fin rays and the melanophores present on the dorsal fin membrane, but differs
from the latter in having a greater body depth, more branched anal fin rays, fewer vertebrae, a lower number of scales in
the lateral series, and differing male nuptial coloration.
Received: June 30, 2000 / Revised: February 21, 2001 / Accepted: March 6, 2001 相似文献
976.
Cerebellar granule and glial cells were cultured from 7 day-old rat pups after pre- and post-natal nicotine treatment. Ten days later, the basal release of glutamate in the granule cells prepared from the pre- and post-natally nicotine-exposed pups was higher and lower than the controls, respectively. The N-methyl-D-aspartate-induced release of glutamate was higher in the granule cells of post-natal nicotine exposed rats. However, the nicotine-induced glutamate release was either unchanged or was lower in the granule cells of all nicotine-treated pups. The basal glutamate uptake was higher in the glial cells from those exposed pre-natally and lower in the continuously nicotine-exposed pups. The sensitivities of L-trans-pyrrolidine-2,4-dicarboxylic acid on glutamate uptake were higher in all nicotine treated groups. There was a higher number of specific [3H]dizocilpine binding sites in the pre- or continuously nicotine-exposed group. These results suggest that the cerebellar cell properties are altered after perinatal nicotine exposure and that the development of an excitatory amino acid system might be affected differently depending on the nicotine exposure time. 相似文献
977.
978.
So Jeong Park Doo Ri Park Deepak Bhattarai Kyeong Lee Jaesang Kim Yun Soo Bae Soo Young Lee 《Molecules and cells》2014,37(8):628-635
2-(Trimethylammonium) ethyl (R)-3-methoxy-3-oxo-2-stearamidopropyl phosphate [(R)-TEMOSPho], a derivative of an organic chemical identified from a natural product library, promotes highly efficient megakaryopoiesis. Here, we show that (R)-TEMOSPho blocks osteoclast maturation from progenitor cells of hematopoietic origin, as well as blocking the resorptive function of mature osteoclasts. The inhibitory effect of (R)-TEMOSPho on osteoclasts was due to a disruption of the actin cytoskeleton, resulting from impaired downstream signaling of c-Fms, a receptor for macrophage-colony stimulating factor linked to c-Cbl, phosphoinositol-3-kinase (PI3K), Vav3, and Rac1. In addition, (R)-TEMOSPho blocked inflammation-induced bone destruction by reducing the numbers of osteoclasts produced in mice. Thus, (R)-TEMOSPho may represent a promising new class of antiresorptive drugs for the treatment of bone loss associated with increased osteoclast maturation and activity. 相似文献
979.
980.
Jongsoo Jeon Jae-won Kim Dongeun Yong Kyungwon Lee Yunsop Chong 《Journal of virology》2012,86(24):13876-13877
Multidrug-resistant Pseudomonas aeruginosa commonly causes serious nosocomial infections. In this study, a novel lytic bacteriophage belonging to a member of the family Podoviridae, YMC01/01/P52 PAE BP, which infects carbapenem-resistant Pseudomonas aeruginosa, was isolated and characterized. YMC01/01/P52 PAE BP genome was analyzed by whole-genome sequencing and putative function identification. The bacteriophage genome consists of a double-stranded linear DNA genome of 49,381 bp with a GC content of 62.16%. 相似文献