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Kiyohito Yoshida Naoto Juni Takeshi Awasaki Yoshiko Tsuriya Naoya Shaya Samuel H. Hori 《Molecular genetics and genomics : MGG》1994,245(5):577-587
Optic morphology (Om) mutations in Drosophila ananassae map to at least 22 loci, which are scattered throughout the genome. Om mutations are all semidominant, neomorphic, nonpleiotropic, and associated with the insertion of a retrotransposon, tom. We have found that the Om(2D) gene encodes a novel protein containing histidine/proline repeats, and is ubiquitously expressed during embryogenesis. The Om(2D) RNA is not detected in wild-type eye imaginal discs, but is abundantly found in the center of the eye discs of Om(2D) mutants, where excessive cell death occurs. D. melanogaster flies transformed with the Om(2D) cDNA under control of the hsp70 promoter display abnormal eye morphology when heat-shocked at the third larval instar stage. These results suggest that the Om(2D) gene is not normally expressed in the eye imaginal discs, but its ectopic expression, induced by the tom element, in the eye disc of third instar larvae results in defects in adult eye morphology. 相似文献
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Transient Ischemia Differentially Increases Tyrosine Phosphorylation of NMDA Receptor Subunits 2A and 2B 总被引:9,自引:4,他引:5
Norio Takagi Kiyohito Shinno Lucy Teves Nankie Bissoon M. Christopher Wallace James W. Gurd 《Journal of neurochemistry》1997,69(3):1060-1065
Abstract: Activation of the N -methyl- d -aspartate (NMDA) receptor has been implicated in the events leading to ischemia-induced neuronal cell death. Recent studies have indicated that the properties of the NMDA receptor channel may be regulated by tyrosine phosphorylation. We have therefore examined the effects of transient cerebral ischemia on the tyrosine phosphorylation of NMDA receptor subunits NR2A and NR2B in different regions of the rat brain. Transient (15 min) global ischemia was produced by the four-vessel occlusion procedure. The tyrosine phosphorylation of NR2A and NR2B subunits was examined by immunoprecipitation with anti-tyrosine phosphate antibodies followed by immunoblotting with antibodies specific for NR2A or NR2B, and by immunoprecipitation with subunit-specific antibodies followed by immunoblotting with anti-phosphotyrosine antibodies. Transient ischemia followed by reperfusion induced large (23–29-fold relative to sham-operated controls), rapid (within 15 min of reperfusion), and sustained (for at least 24 h) increases in the tyrosine phosphorylation of NR2A and smaller increases in that of NR2B in the hippocampus. Ischemia-induced tyrosine phosphorylation of NR2 subunits in the hippocampus was higher than that of cortical and striatal NR2 subunits. The enhanced tyrosine phosphorylation of NR2A or NR2B may contribute to alterations in NMDA receptor function or in signaling pathways in the postischemic brain and may be related to pathogenic events leading to neuronal death. 相似文献
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Recently we found that raising the intraluminal pressure caused an increase in the luminal release of serotonin from enterochromaffin
(EC) cells and serotonin immunoreactivity normally restricted within the secretory granules was diffusely scattered over the
extragranular matrix. In the present study we investigated the intracellular localization of chromogranin A, a protein co-stored
with serotonin in the EC cells, after stimulating the luminal release of serotonin. In situ vascularly and luminally perfused
rat duodenum was exposed to intraluminal pressure and fixed for immunoelectron microscopic study. For immunoelectron microscopy,
the pre-embedding DAB reaction for serotonin combined with the postembedding immunogold reaction for chromogranin A was used.
Results showed that a number of secretory granules labeled with immunogold chromogranin A immunoreactivity located close to
the apical plasma membrane. Some EC cells showed that one part of the apical cytoplasm was protruded into the lumen and a
number of secretory granules with immunogold labeling were included in the protruded cytoplasm. These results suggest that
EC cells may release chromogranin A into the intestinal lumen together with serotonin, by means of a different manner of secretion
from that in serotonin.
Received / Accepted: 9 December 1998 相似文献
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Adenoviral transfection of hepatocytes with the thioredoxin gene confers protection against apoptosis and necrosis 总被引:3,自引:0,他引:3
Tsutsui T Koide H Fukahori H Isoda K Higashiyama S Maeda I Tashiro F Yamato E Miyazaki J Yodoi J Kawase M Yagi K 《Biochemical and biophysical research communications》2003,307(4):765-770
A recombinant adenovirus vector containing the human thioredoxin (TRX) gene was constructed using the Cre-loxP recombination system and used to transfect rat hepatocytes with very high efficiency. The TRX gene was expressed in a dose-dependent manner and significantly modulated rat cellular functions. The TRX gene conferred resistance to oxidative stress, such as hydrogen peroxide treatment, on the host hepatocytes. FACS analysis of DNA fragmentation showed that the TRX gene suppressed hepatocyte apoptosis. It also significantly extended the life span of hepatocytes cultured conventionally on polystyrene plates. Liver-specific functions were maintained in the viability-modulated hepatocytes. Moreover, TRX expression did not affect hepatocyte spheroid formation and it extensively suppressed necrosis in the internal cells. Thus, the transfection of hepatocytes with the TRX gene successfully confers global maintenance of liver functions. These findings provide important information for the development of bioartificial liver support systems and gene therapy for liver diseases. 相似文献
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Growth of and hydrogen production by wild-type (WT) Rhodovulum sulfidophilum were compared with those by one of its mutants lacking the poly(3-hydroxybutyrate) (PHB) biosynthesis ability (PNM2). During phototrophic growth under aerobic conditions with fixed illumination, changes in the extinction coefficient and PHB content of WT and PNM2 cells revealed interference of light penetration by PHB. WT cells synthesized PHB at an early stage of the cultivation. PHB degradation after exhaustion of acetate during the cultivation of WT resulted in a decrease of the extinction coefficient. The hydrogen production rate under anaerobic conditions with fixed illumination was examined in WT and PNM2 cell suspensions at different densities. The hydrogen production rate was determined not by the light penetration but by the kinds of hydrogen donors and the density of suspension. The highest value of the rate of hydrogen production from PHB, 33.0 ml/l/h, was improved compared with 26.6 ml/l/h, which was the highest value in hydrogen production from succinate. Under the same illumination, conversion to hydrogen from PHB is more efficient than that from succinate, which is one of the best substrates for hydrogen production. These results suggest that the hydrogen production rate can be maximized in the hydrogen production system based on PHB degradation, which is achieved in high-density suspension under external-substrate-depleted conditions after aerobic cultivation in the presence of an excess amount of acetate. 相似文献
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Takahashi N Kawada T Yamamoto T Goto T Taimatsu A Aoki N Kawasaki H Taira K Yokoyama KK Kamei Y Fushiki T 《The Journal of biological chemistry》2002,277(19):16906-16912
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Maeda I Yamashiro H Yoshioka D Onodera M Ueda S Miyasaka H Umeda F Kawase M Takaichi S Yagi K 《Current microbiology》2005,51(3):193-197
Rhodovulum sulfidophilum produces carotenoids in the spheroidene pathway. Spheroidene monooxygenase, CrtA, catalyzes the conversion of spheroidene to spheroidenone. crtA-deleted mutants of R. sulfidophilum did not produce spheroidenone and demethylspheroidenone. In these mutants, the ratio of demethylspheroidene to spheroidene increased with exposure to light. One mutant exhibiting a spheroidene-predominant phenotype did not grow under anaerobic-light conditions and was devoid of bacteriochlorophyll a, even under semiaerobic-light conditions There was no difference in the growth of the mutants under aerobic-dark conditions. These data suggest that demethylspheroidene is important for photosynthesis in R. sulfidophilum. 相似文献
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Takahiro Wakahama Aitor Laza‐Martínez Ahmad Iskandar Bin Haji Mohd Taha Hidetoshi Okuyama Kiyohito Yoshida Kazuhiro Kogame Koichiro Awai Masanobu Kawachi Takashi Maoka Shinichi Takaichi 《Journal of phycology》2012,48(6):1392-1402
The molecular structure of the carotenoid lactoside P457, (3S,5R,6R,3′S,5′R,6′S)‐13′‐cis‐5,6‐epoxy‐3′,5′‐dihydroxy‐3‐(β‐d ‐galactosyl‐(1→4)‐β‐d ‐glucosyl)oxy‐6′,7′‐didehydro‐5,6,7,8,5′,6′‐hexahydro‐β,β‐caroten‐20‐al, was confirmed by spectroscopic methods using Symbiodinium sp. strain NBRC 104787 cells isolated from a sea anemone. Among various algae, cyanobacteria, land plants, and marine invertebrates, the distribution of this unique diglycosyl carotenoid was restricted to free‐living peridinin‐containing dinoflagellates and marine invertebrates that harbor peridinin‐containing zooxanthellae. Neoxanthin appeared to be a common precursor for biosynthesis of peridinin and P457, although neoxanthin was not found in peridinin‐containing dinoflagellates. Fucoxanthin‐containing dinoflagellates did not possess peridinin or P457; green dinoflagellates, which contain chlorophyll a and b, did not contain peridinin, fucoxanthin, or P457; and no unicellular algae containing both peridinin and P457, other than peridinin‐containing dinoflagellates, have been observed. Therefore, the biosynthetic pathways for peridinin and P457 may have been coestablished during the evolution of dinoflagellates after the host heterotrophic eukaryotic microorganism formed a symbiotic association with red alga that does not contain peridinin or P457. 相似文献
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