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Negative regulation of TGF-β signaling in development

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Cell Research 2004年第6期14卷 441-449页

作者： Ye Guang CHEN, An Ming MENG The state key laboratory of biomembrane and membrane biotechnology, Department of Biological sciences and biotechnology, tsinghua university, Beijing 100084, china Department of Biological sciences and biotechnology The State Key Laboratory of Biomembrane and Membrane Biotechnology Tsinghua University Beijing 100084 China

The TGF-β superfamily members have important roles in controlling patterning and tissue formation in both invertebrates and vertebrates. Two types of signal transducers, receptors and Smads, mediate the signaling to regulate expression of their target genes. Despite of the relatively simple signal transduction pathway, many modulators have been found to contribute to a tight regulation of this pathway in a variety of mechanisms. This article reviews the negative regulation of TGF-β signaling with focus on its roles in vertebrate development.

关键词： TGF-β BMP Nodal Activin antagonist development negative regulation.

Electrophysiological research of synapse formation from beginning to maturity

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Chinese Science Bulletin 1998年第1期43卷 55-59页

作者： XIE Zuoping and ZHENG Yufang state key laboratory of biomembrane and membrane Biotechnique Department of Biological sciences and biotechnology, tsinghua university, Beijing 100084, china state key laboratory of biomembrane and membrane Biotechnique Tsinghua University Beijing China Department of Biological sciences and biotechnology Tsinghua University Beijing China

The development of synapses is an important question in neurobiology. We employ patchclamp technique to record MEPCs and EPCs of myoballs in Xenopus cell culture. The rate of EPC/MEPC is related with synapses maturation. Accordingly, we define the mature synapses as those whose rate of presynaptic membrane’s EPC to MEPC is more than 8. The process of maturation needs about 2-5 h after neurites contact with myoballs. We divide the development of synapses into three stages: young, developing and mature. The neurotransmitters stack gradually and increase by hundreds of times along with young synapses growing into maturity. So the process of synapses maturation should include presynaptic membrane specialization, postsynaptic membrane specialization and neurotransmitters stack.

关键词： definition of mature synapse α latrotoxin (α LTX) neurotransmitter stack.

A measurement error model for microarray data analysis

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Progress in Natural Science:Materials International 2005年第7期15卷 614-620页

作者： ZHOU Yiming and CHENG Jing ( Department of Biological sciences and biotechnology, tsinghua university, Beijing 100084, china state key laboratory of biomembrane and membrane biotechnology, tsinghua university, Beijing 100084, china National Engineering Research Center for Beijing Biochip Technology, 18 life Science Parkway, Beijing 102206, china) Department of Biological sciences and biotechnology Tsinghua University Beijing 100084 China. state key laboratory of biomembrane and membrane biotechnology Tsinghua University Beijing 100084 China. National Engineering Research Center for Beijing Biochip Technology 18 Life Science Parkway Beijing 102206 China

Microarray technology has been widely used to analyze the gene expression levels by detecting fluorescence intensity in a high throughput fashion. However, since the measurement error produced from various sources in microarray experiments is heterogeneous and too large to be ignored, we propose here a measurement error model for microarray data processing, by which the standard deviation of the measurement error is demonstrated to be linearly increased with fluorescence intensity. A robust algorithm, which estimates the parameters of the measurement error model from a single microarray without replicated spots, is provided. The model and algorithm for estimating of the parameters from a given data set are tested on both the real data set and the simulated data set, and the result has been proven satisfactory. And, combining the measurement error model with traditional Z-test method, a full statistical model has been developed It can significantly improve the statistical inference for identifying differentially expressed genes.

关键词： microarray measurement error model parameter estimation differentially expressed genes.

Structure and regulatory function of plant transcription factors

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Chinese Science Bulletin 2001年第4期46卷 271-278页

作者： LIU Qiang, ZHANG Guiyou & CHEN ShouyiDepartment of Biological Science and biotechnology, tsinghua Univorsity, Beijing 100084, china Department of Biological Science and biotechnology, state laboratory of biomembrane and membrane biotechnology, tsinghua university, Beijing 100084, china Institute of Genetics, Chinese Academy of sciences, Beijing 100101, china Department of Biological Science and biotechnology Tsinghua University Beijing China Department of Biological Science and biotechnology State Laboratory of Biomembrane and Membrane Biotechnology Tsinghua University Beijing China Institute of Genetics Chinese Academy of Sciences Beijing China

The expression of inducible genes in plants is regulated by specific transcription factors at the transcrip-tional level. A typical transcription factor usually contains a DNA-binding domain, a transcription regulation domain, a dimerization site and a nuclear localization domain. These functional domains define the characteristic, localization and regulatory role of a transcription factor. Transcription factors recognize and bind to specific cis-acting elements or interact with other proteins, and then activate or repress the transcription of target genes by their functional domains. In recent years, elucidation on the structure and function of transcription factors has become an important subject in plant molecular biology.

关键词： transcription factor DNA-binding domain cis-acting element.

Analysis micro-mechanism of burrs formation in the case of nanometric cutting process using numerical simulation method

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Science china(Technological sciences) 2007年第2期50卷 129-137页

作者： HAN XueSong & HU YuanZhong state key laboratory of Tribology, tsinghua university, Beijing 100084, china 1. state key laboratory of Tribology Tsinghua University Beijing 100084 China

Burrs (exit failure), being one of the important factors influencing the final precision of workpiece, have been widely studied. Today, with the development of manufacturing technology, the depth of cut falls into the range of nanometer or subnanometer, there may be some different disciplines dominating the burrs generation process. Molecular dynamics (MD) emthod, which is different from continuous mechanics, plays an important role in describing microscopic world. Take the example of single crystal copper, this paper carries out MD analysis micro-mechanism of burrs generation process. The results show that the burrs geometry depends on the type of workpiece (ductile or brittle). The depth of cut is decreased in the case of positive burrs generation process while the depth of cut is increased in case of negative burrs generation process. keywords burr - molecular dynamics - micro-mechanism Supported by china Postdoctor Science Foundation (Grant No. 20060390458)

关键词： burr molecular dynamics micro-mechanism

Plant protein kinase genes induced by drought, high salt and cold stresses

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Chinese Science Bulletin 2000年第13期45卷 1153-1157页

作者： LIU Qiang , ZHANG Yong & Chen Shouyi1. Deparlmenl of Biological Science and biotechnology, tsinghua university, Beijing 100084, china 2. Department of Biological Science and biotechnology, Slate key laboratory of biomembrane and membrane biotechnology, tsinghua university, Beijing 100084, china 3. Institute of Genetics, Chinese Academy of sciences, Beijing 100101, china Department of Biological Science and biotechnology Tsinghua University Beijing China Department of Biological Science and biotechnology State Key Laboratory of Biomembrane and Membrane Biotechnology Tsinghua University Beijing China Institute of Genetics Chinese Academy of Sciences Beijing China

Drought, high salt and cold are three different kinds of environment stresses that severely influence the growth, development and productivity of crops. They all decrease the water state of plant cells, and consequently result in the harm of plant from water deficit. Several genes encoding protein kinases and induced by drought, high salt and low temperature have been isolated from Arabidopsis. These protein kinases include receptor protein kinase (RPK), MAP kinases, ribosomal-protein kinases and transcription-regulation protein kinase. The expression features of these genes and the regulatory roles of these protein kinases in stress response and signal transduction are discussed.

关键词： protein kinase environment stress signal transduction gene expression.

Two forms of the membrane-bound state of the first C2 domain (C2A) of synaptotagminⅠand calcium-triggered membrane insertion

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Chinese Science Bulletin 2003年第17期48卷 1822-1827页

作者： HE Yuhong, LI Xianghui, WANG Fu, XUE Yi & SUI Senfang Department of Biological sciences & biotechnology, state key Labora-tory of biomembrane, tsinghua university, Beijing 100084, china Department of Biological sciences and biotechnology State Key Laboratory of Biomembrane Tsinghua University Beijing 100084 China

The synaptic vesicle protein synaptotagminⅠ (sytⅠ) is a vesicle transmembrane protein present in synap-tic vesicles, which has been proposed as the Ca2+ sensor that regulates secretion. The C2A domain is the membrane proximal part of its cytoplasmic domain. The interaction between C2A and lipid bilayer has been considered to be essential for triggering neurotransmitter release. In the pre-sent work, the measurements of membrane surface tension and surface concentration showed that the C2A domain of sytⅠexhibited two membrane-bound states: the surface adsorption state and the membrane insertion state. The sur-face absorption state formed in a Ca2+-independent manner with lower affinity, while the membrane insertion state formed with high affinity was only found in the presence of Ca2+. Both the Ca2+-independent and Ca2+-dependent sytⅠ- membrane interactions required anionic phospholipids, such as phosphatidylserine (PS). When expressed into rat pheo-chromocytoma (PC12. cells and human embryonic kidney (HEK-293) cells, as demonstrated by immunofluorescence staining and subcellular fractionation, most of the C2A was found at the plasma membrane, even when the cells were depleted of Ca2+ by incubation with EGTA. These results suggested a new molecular mechanism of sytⅠas a Ca2+ sensor in membrane fusion. Ca2+-independent surface ad-sorption might attach sytⅠto the release site during the docking or priming step. When intracellular Ca2+ increased, sytⅠtriggered the neurotransmitter release following the Ca2+-dependent penetration into the target membrane.

关键词：突触小泡蛋白质膜贯通蛋白质钙离子薄膜插入 C2A 薄膜边界状态

Mitochondrial membrane fusion and ATP synthesis both compete for interfacial △pH of PMF,but not △Ψ:An Inter-play between membrane fusion and energy coupling of mitochondria

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生物物理学报 2009年第S1期25卷 217-218页

作者： Shusen Liu state key laboratory of biomembrane and membrane biotechnology, Instutute of Zoology, Chinese Academy of sciences, Beijing, 100101, china

Although some fusogenic proteins have been established to tether two opposite outer or inner mitochondrial membranes into contact, a prerequisite for whole mitochondrial fusion events,

关键词： Mitochondrial membrane fusion Protein-tethering Lipid-bilayer-mixing and fusion Interfacial △pH of PMF.Inter-play between membrane fusion and ATP synthesis.

Effects of genistein, daidzein and glycitein on the osteogenic and adipogenic differentiation of bone marrow stromal cells and on the adipogenic trans-differentiation of osteoblasts

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Progress in Natural Science:Materials International 2005年第11期15卷 993-999页

作者： LI Xianghui, ZHANG Jinchao, SUI Senfang and YANG Mengsu (state key laboratory of biomembrane, Department of Biological sciences and biotechnology, tsinghua university, Beijing 100084, china Department of Chemistry, College of Chemistry & Environmental Science, Hebei university, Baoding 071002, china Department of Biology and Chemistry, City university of Hong Kong, Hong Kong, china) state key laboratory of biomembrane Department of Biological Sciences and Biotechnology Tsinghua University Beijing 100084 China. Department of Chemistry College of Chemistry & Environmental Science Hebei University Baoding 071002 China. Department of Biology and Chemistry City University of Hong Kong Hong Kong China

The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT), alkaline phosphatase (ALP) activity and oil red O assays were used to examine the effects of genistein, daidzein and glycitein on the osteogenic and adipogenic differentiation of primary mouse bone marrow stromal cells (MSCs) and the adipogenic trans-differentiation of primary mouse osteoblasts. The results indicated that daidzein, genistein and glycitein at concentrations from 1×10-8 mol/L to 1×10-5mol/L promoted the proliferation of MSCs and osteoblasts; genistein, daidzein and glycitein promoted osteogenic differentiation and inhibited adipogenic differentiation of MSCs, and inhibited adipocytic transdifferentiation of osteoblasts at appropriate concentrations as 17β-estradiol. It suggests that genistein, daidzein and glycitein regulate a dual differentiational process of MSCs into the osteogenic and adipogenic lineages, and trans-differentiational process of primary osteoblasts into the adipocyte lineages, causing a lineage shift toward osteoblast. Protective effects of them on bone may be mediated by a reversal of adipogenesis which may promote the proliferation, differentiation and mineralization of osteoblasts, and make adipocytes secrete less cytokines which may promote osteoclast formation and activation. In addition, the results also indicated that genistein, daidzein and glycitein may be helpful in preventing the development of steroid induced osteonecrosis.

关键词： genistein daidzein glycitein bone marrow stromal cells osteoblasts osteogenic differentiation adipogenic differentiation adipogenic trans-differentiation.