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981.
Peng Zhenying Ruan Jian Tian Haiying Shan Lei Meng Jingjing Guo Feng Zhang Zhimeng Ding Hong Wan Shubo Li Xinguo 《Plant Molecular Biology Reporter》2020,38(2):209-221
Plant Molecular Biology Reporter - The synthesis of α-linolenic acid (ALA) requires the activity of ω-3 fatty acid desaturases (ω-3 FADs). The quality of peanut oil would be much... 相似文献
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P2 receptors have been implicated in the release of neurotransmitter and proinflammatory cytokines by the response to neuroexcitatory substances in astrocytes. In the present study, we examined the mechanisms of ADP and adenosine 5'-O-2-thiodiphosphate (ADPbetaS, ADP analogue) on glutamate release from cultured dorsal spinal cord astrocytes by using confocal laser scanning microscopy and HPLC. Immunofluorescence activity showed that P2Y1 receptor protein is expressed in cultured astrocytes. ADP and ADPbetaS-induced [Ca2+ ]i increase and glutamate release are mediated by P2Y1 receptor. Ca2+ release from IP3 -sensitive calcium stores and protein kinase C (PKC) activation is important for glutamate release from astrocytes. Furthermore, P2Y1 receptor-evoked glutamate release is regulated by volume-sensitive Cl− channels and anion co-transporter, which open up the possibility that P2Y1 receptor activation causes the increase of cell volume. Release of glutamate by ADPbetaS was abolished by 5-nitro-2 (3-phenyl propy lamino)–benzoate plus furosemide but was unaffected by botulinum toxin A. These observations indicate that P2Y1 receptor-evoked glutamate may be mediated via volume-sensitive Cl− channel but not via exocytosis of glutamate containing vesicles. We speculate that P2Y1 receptors-evoked glutamate efflux, occurring under pathological condition, may modulate the activity of synapses in spinal cord. 相似文献
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Xiao-Long Zhou Zhi-Rong Ruan Qian Huang Min Tan En-Duo Wang 《Nucleic acids research》2013,41(1):302-314
Aminoacyl-tRNA synthetase (aaRS) catalyzes the first step of protein synthesis, producing aminoacyl-tRNAs as building blocks. Eukaryotic aaRS differs from its prokaryotic counterpart in terminal extension or insertion. Moreover, the editing function of aaRSs is an indispensable checkpoint excluding non-cognate amino acids at a given codon and ensuring overall translational fidelity. We found higher eukaryotes encode two cytoplasmic threonyl-tRNA synthetases (ThrRSs) with difference in N-terminus. The longer isoform is more closely related to the ThrRSs of higher eukaryotes than to those of lower eukaryotes. A yeast strain was generated to include deletion of the thrS gene encoding ThrRS. Combining in vitro biochemical and in vivo genetic data, ThrRSs from eukaryotic cytoplasm were systematically analyzed, and role of the eukaryotic cytoplasmic ThrRS-specific N-terminal extension was elucidated. Furthermore, the mechanisms of aminoacylation and editing activity mediated by Saccharomyces cerevisiae ThrRS (ScThrRS) were clarified. Interestingly, yeast cells were tolerant of variation at the editing active sites of ScThrRS without significant Thr-to-Ser conversion in the proteome even under significant environmental stress, implying checkpoints downstream of aminoacylation to provide a further quality control mechanism for the yeast translation system. This study has provided the first comprehensive elucidation of the translational fidelity control mechanism of eukaryotic ThrRS. 相似文献
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Zhensheng Yue Zijian Jiang Bai Ruan Juanli Duan Ping Song Jingjing Liu Hua Han Lin Wang 《International journal of biological sciences》2021,17(9):2135
The phenotypic transformation of hepatic myofibroblasts (MFs) is involved in the whole process of the progression and regression of liver fibrosis. Notch signaling has been demonstrated to modulate the fibrosis. In this study, we found that Notch signaling in MFs was overactivated and suppressed with the progression and regression of hepatic fibrosis respectively, by detecting Notch signaling readouts in MFs. Moreover, we inactivated Notch signaling specifically in MFs with Sm22αCreER-RBPjflox/flox mice (RBPjMF-KO), and identified that MFs-specific down-regulation of Notch signaling significantly alleviated CCl4-induced liver fibrosis during the progression and regression. During the progression of liver fibrosis, MFs-specific blockade of Notch signaling inhibited the activation of HSCs to MFs and increases the expression of MMPs to reduce the deposition of ECM. During the regression of fibrosis, blocking Notch signaling in MFs increased the expression of HGF to promote proliferation in hepatocytes and up-regulated the expression of pro-apoptotic factors, Ngfr and Septin4, to induce apoptosis of MFs, thereby accelerating the reversal of fibrosis. Collectively, the MFs-specific disruption of Notch signaling attenuates liver fibrosis by modulating fibrosis progression and regression, which suggests a promising therapeutic strategy for liver fibrosis. 相似文献
988.
Shigui Ruan 《Journal of mathematical biology》1993,31(6):633-654
We consider plankton-nutrient interaction models consisting of phytoplankton, herbivorous zooplankton and dissolved limiting nutrient with general nutrient uptake functions and instantaneous nutrient recycling. For the model with constant nutrient input and different constant washout rates, conditions for boundedness of the solutions, existence and stability of non-negative equilibria, as well as persistence are given. We also consider the zooplankton-phytoplankton-nutrient interaction models with a fluctuating nutrient input and with a periodic washout rate, respectively. It is shown that coexistence of the zooplankton and phytoplankton may arise due to positive bifurcating periodic solutions.Research has been supported in part by a University of Alberta Ph.D. Scholarship and is in part based on the author's Ph.D. thesis under the supervision of Professor H. 1. Freedman, to whom the author owes a debt of appreciation and gratitude for his kind advice, helpful comments and continuous encouragement 相似文献
989.
Twenty days’ exposure to 50 or 100 mM NaCl in the rooting medium substantially increased fresh and dry weights of seedling
shoots of the recretohalophyte Limonium sinense while 200 or 300 mM were increasingly inhibitory. KCl treatment was only slightly stimulating (50 mM) or strongly inhibitory
(100–300 mM). Lesser effects on leaf area were also seen. Diameter of foliar salt glands was significantly larger than that
of controls in 100 and 200 mM NaCl with the effect being reversed at higher concentrations. Gland enlargement was also observed
in the presence of 100 mM KCl, while larger concentrations reduced gland size. Generally, gland diameter was larger in the
presence of NaCl than in KCl. NaCl and KCl also increased gland number per leaf and secretion rate per gland. At 100 and 200 mM
NaCl or KCl, Na+ secretion per leaf from NaCl-treated plants exceeded K+ secretion rate from KCl-treated plants while at 200 mM, Na+ secretion per gland was significantly higher for Na+ than for K+. Evidence of cell death in leaves of salt-treated plants using Evans blue staining indicates that release of cell contents
through loss of membrane integrity contributed to the secretion values. We conclude that the greater tolerance of L. sinenseto to NaCl compared to KCl is linked to the more effective secretion of Na+ than of K+ and, in turn, to a greater stimulation of salt gland formation and activity and larger gland diameter. 相似文献
990.