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81.
Tamoi M Hiramatsu Y Nedachi S Otori K Tanabe N Maruta T Shigeoka S 《Photosynthesis research》2011,108(1):15-23
We generated transgenic tobacco plants with high levels of fructose-1,6-bisphosphatase expressing cyanobacterialfructose-1,6-/sedoheptulose-1,7-bisphosphatase
in the cytosol. At ambient CO2 levels (360 ppm), growth, photosynthetic activity, and fresh weight were unchanged but the sucrose/hexose/starch ratio was
slightly altered in the transgenic plants compared with wild-type plants. At elevated CO2 levels (1200 ppm), lateral shoot, leaf number, and fresh weight were significantly increased in the transgenic plants. Photosynthetic
activity was also increased. Hexose accumulated in the upper leaves in the wild-type plants, while sucrose and starch accumulated
in the lower leaves and lateral shoots in the transgenic plants. These findings suggest that cytosolic fructose-1,6-bisphosphatase
contributes to the efficient conversion of hexose into sucrose, and that the change in carbon partitioning affects photosynthetic
capacity and morphogenesis at elevated CO2 levels. 相似文献
82.
Real-time observation of conformational fluctuations in Zn-substituted myoglobin by time-resolved transient hole-burning spectroscopy. 总被引:1,自引:0,他引:1
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Equilibrium fluctuations of the protein conformation have been studied in myoglobin by a novel method of time-resolved transient hole-burning spectroscopy over a temperature range of 180-300 K and a time range of 10 ns to 10 ms. The temporal shift of the hole spectrum has been observed in a wide temperature region of 200-300 K. It has been found that the time behavior of the peak position of the hole is highly nonexponential and can be expressed by a stretched exponential function with a beta value of 0.22. As compared with the results for a dye solution sample, the time scale of the fluctuation of the protein conformation is much more weakly dependent on temperature. The time scale of the observed conformational dynamics shows a temperature dependence similar to that associated with the ligand escape process of myoglobin. 相似文献
83.
Cutting edge: SR-PSOX/CXC chemokine ligand 16 mediates bacterial phagocytosis by APCs through its chemokine domain 总被引:11,自引:0,他引:11
Shimaoka T Nakayama T Kume N Takahashi S Yamaguchi J Minami M Hayashida K Kita T Ohsumi J Yoshie O Yonehara S 《Journal of immunology (Baltimore, Md. : 1950)》2003,171(4):1647-1651
SR-PSOX and CXC chemokine ligand (CXCL)16, which were originally identified as a scavenger receptor and a transmembrane-type chemokine, respectively, are indicated to be identical. In this study, we demonstrate that membrane-bound SR-PSOX/CXCL16 mediates adhesion and phagocytosis of both Gram-negative and Gram-positive bacteria. Importantly, our prepared anti-SR-PSOX mAb, which suppressed chemotactic activity of SR-PSOX, significantly inhibited bacterial phagocytosis by human APCs including dendritic cells. Various scavenger receptor ligands inhibited the bacterial phagocytosis of SR-PSOX. In addition, the recognition specificity for bacteria was determined by only the chemokine domain of SR-PSOX/CXCL16. Thus, SR-PSOX/CXCL16 may play an important role in facilitating uptake of various pathogens and chemotaxis of T and NKT cells by APCs through its chemokine domain. 相似文献
84.
Tatsuya Kawato Eiichi Mizohata Yohei Shimizu Tomohiro Meshizuka Tomohiro Yamamoto Noriaki Takasu 《Bioscience, biotechnology, and biochemistry》2013,77(4):640-642
The streptavidin/biotin interaction has been widely used as a useful tool in research fields. For application to a pre-targeting system, we previously developed a streptavidin mutant that binds to an iminobiotin analog while abolishing affinity for natural biocytin. Here, we design a bivalent iminobiotin analog that shows 1000-fold higher affinity than before, and determine its crystal structure complexed with the mutant protein. 相似文献
85.
Kaseda R Iino N Hosojima M Takeda T Hosaka K Kobayashi A Yamamoto K Suzuki A Kasai A Suzuki Y Gejyo F Saito A 《Biochemical and biophysical research communications》2007,357(4):1130-1134
Serum levels of cystatin C, an endogenous cysteine proteinase inhibitor, are often used as an indicator of glomerular filtration rate. Although it is known that cystatin C is filtered by glomeruli and metabolized in proximal tubule cells (PTC), the precise molecular mechanism underlying this process is undetermined. Using quartz-crystal microbalance analyses, we demonstrate that cystatin C binds directly to megalin, an endocytic receptor in PTC, in a Ca(+)-dependent manner. We also find that cystatin C is endocytosed specifically via megalin in rat yolk sac epithelium-derived L2 cells which share a variety of characteristics with PTC. Finally, in vivo studies using kidney-specific megalin knockout mice provide evidence that megalin mediates proximal tubular uptake of cystatin C. We conclude that megalin is an endocytic receptor of cystatin C in PTC. 相似文献
86.
Fukuya H Emoto N Nonaka H Yagita K Okamura H Yokoyama M 《Biochemical and biophysical research communications》2007,354(4):924-928
In mammals, behavioral and physiological processes display 24-h rhythms that are regulated by a circadian system. In the present study, we investigated the possibility that the expression of clock genes in peripheral leukocytes can be used to assess the circadian clock system. We found that Per1 and Per2 exhibit circadian oscillations in mRNA expression in mouse peripheral leukocytes. Furthermore, the rhythms of Per1 and Per2 mRNA expression in peripheral leukocytes are severely blunted in homozygous Cry1/2 double-deficient mice that are known to have an abolished biological clock. We have examined the circadian expression of clock genes in human leukocytes and found that Per1 mRNA exhibits a robust circadian expression while Per2 and Bmal1 mRNA showed weak rhythm. These observations suggest that monitoring Per1 mRNA expression in human leukocytes may be useful for investigating the function of the circadian system in physiological and pathophysiological states. 相似文献
87.
Bae Gong Young; Nakajima Nobuyoshi; Ishizuka Kozo; Kondo Noriaki 《Plant & cell physiology》1996,37(2):129-134
The rate of evolution of ethylene by tomato plants was rapidlyincreased by O3 fumigation. The time course of the increasein 1-aminocyclopropane-1-carboxylic acid (ACC) synthase activitywas the same as that in the rate of evolution of ethylene, suggestingthat ACC synthase activity might be a rate-limiting step inthe evolution of ethylene that is caused by O3 fumigation. Therate of the O3-induced evolution of ethylene was increased bythe application of ACC to tomato plants, suggesting the involvementof ACC oxidase in the O3-induced evolution of ethylene. Treatmentof plants with tiron inhibited the evolution of ethane, butnot of ethylene. These results indicated that evolution of ethylenein O3-treated tomato plants might result from enzymatic reactionscatalyzed by both ACC synthase and ACC oxidase, but not fromstimulation by O3 of the peroxidation of lipids mediated byfree radicals. Pretreatment of leaves with aminoethoxyvinylglycine (AVG), aninhibitor of ACC synthase, significantly inhibited the evolutionof ethylene that was induced by O3 and concomitantly reducedthe extent of O3-induced visible damage to leaves. Treatmentwith 2,5-norbonadiene, an inhibitor of the action of ethylene,strongly reduced the extent of visible damage caused by O3,even though it did not suppress the evloution of ethylene. Theseresults indicate that ethylene acts on certain metabolic processesto cause visible damage. (Received September 7, 1995; Accepted December 18, 1995) 相似文献
88.
H. Tamegai Lina Li Noriaki Masui Chiaki Kato 《Extremophiles : life under extreme conditions》1997,1(4):207-211
The denitrifying bacterium strain MT-1 was isolated from the mud of the Mariana Trench. The optimal temperature and pressure
for growth of this bacterium were found to be 30°C and 0.1 MPa, respectively. However, it showed greater tolerance to low
temperature (4°C) and high hydrostatic pressure (50 MPa) as compared with denitrifiers obtained from land. From the results,
it can be said that this organism is adapted to the environment of the deep sea. Strain MT-1 was shown to belong to the genus
Pseudomonas by analysis of its 16S rDNA. The cytochrome contents of the bacterium were similar to those of Ps. stutzeri in spectrophotometric studies.
Received: June 2, 1997 / Accepted: August 9, 1997 相似文献
89.
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