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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 {3. and {3. Biotechnique Department of Biological Sciences and biotechnology, tsinghua university, Beijing 100084, china state key laboratory of {3. and {3. 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.

Regulation of embryonic stem cell self-renewal and differentiation by TGF-β family signaling

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Science china(Life Sciences) 2010年第4期53卷 497-503页

作者： FEI Teng & CHEN Ye-Guang The state key laboratory of biomembrane and membrane biotechnology, School of Life Sciences, tsinghua university, Beijing 100084, china The state key laboratory of biomembrane and membrane biotechnology School of Life Sciences Tsinghua University Beijing China

Embryonic stem (ES) cells are characterized by their ability to indefinitely self-renew and potential to differentiate into all the cell lineages of the body. ES cells are considered to have potential applications in regenerative medicine. In particular, the emergence of an ES cell analogue-induced pluripotent stem (iPS) cells via somatic cell reprogramming by co-expressing a limited number of critical stemness-related transcriptional factors has solved the problem of obtaining patient-specific pluripotent cells, encouraging researchers to develop more specific and functional cell lineages from ES or iPS cells for broad therapeutic applications. ES cell fate choice is delicately controlled by a core transcriptional network, epigenetic modification profiles and complex signaling cascades both intrinsically and extrinsically. Of these signals, transforming growth factor β (TGF-β) family members, including TGF-β, bone morphogenetic protein (BMP), Activin and Nodal, have been reported to influence cell self-renewal and a broad spectrum of lineage differentiation in ES cells, in accordance with the key roles of TGF-β family signaling in early embryo development. In this review, the roles of TGF-β family signals in coordinating ES cell fate determination are summarized.

关键词： embryonic stem cell TGF-β BMP Activin Nodal self-renewal differentiation

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 {3., 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.

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.

Cellular mechanism for spontaneous calcium oscillations in astrocytes

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Acta Pharmacologica Sinica 2006年第7期27卷 861-868页

作者： Tong-fei WANG~2 Chen ZHOU~2 Ai-hui TANG Shi-qiang WANG Zhen CHAI~3.state key laboratory of biomembrane and membrane biotechnology,College of Life Sciences,Peking university,Beijing 100871,china state key laboratory of biomembrane and membrane biotechnology College of Life Sciences Peking University Beijing China

Aim:To determine the Ca2+source and cellular mechanisms of spontaneous Ca2+oscillations in hippocampal ***:The cultured cells were loadedwith Fluo-4 AM,the indicator of intracellular Ca2+,and the dynamic Ca2+tran-sients were visualized with confocal laser-scanning ***:Thespontaneous Ca2+oscillations in astrocytes were observed first in co-culturedhippocampal neurons and *** oscillations were not affected bytetrodotoxin(TTX)treatment and kept up in purity cultured *** Ca2+oscillations were not impacted after blocking the voltage-gatedCa2+channels or ethylenediamine tetraacetic acid(EDTA)bathing,indicating thatintracellular Ca2+elevation was not the result of extracellular Ca2+***,the correlation between the spontaneous Ca2+oscillations and theCa2+store in endoplasmic reticulum(ER)were investigated with *** oscillations were:1)enhanced when cells were exposed to bothlow Na~+(70 mmol/L)and high Ca2+(5 mmol/L)solution,and eliminated completelyby 2 μmol/L thapsigargin,a blocker of sarcoplasmic reticulum Ca2+-ATPase;and2)still robust alter the application with either 50μmol/L ryanodine or 400μmol/Ltetracaine,two specific antagonists of ryanodine receptors,but depressed in adose-dependent manner by 2-APB,an InsP3.eceptors(InsP3.)***:InsP3.-induced ER Ca2+release is an important cellular mechanismfor the initiation of spontaneous Ca2+oscillation in hippocampal astrocytes.

关键词： hippocampal astrocytes spontaneous Ca2+ oscillations endoplasmic reticulum Ca2+ store InsP3.receptors confocal laser scanning microscope

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.

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.

PTEN,a general negative regulator of cyclin D expression

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Cell Research 2007年第4期17卷 291-292页

作者： Eirong Diao~1 Ye-Guang Chen ~1state key laboratory of biomembrane and membrane biotechnology,Department of Biological Sciences and biotechnology Tsing-hua Universiry,Beijing 100084,china Department of Biological Sciences and biotechnology State Key Laboratory of Biomembrane and Membrane Biotechnology Tsinghua University Beijing China

The tumor-suppressor phosphatase with tensin homol-ogy(PTEN)is frequently mutated in many malignanciesand is one of the most well studied tumor suppressor genes[1,2].PTEN,a lipid and protein dual phosphatase,plays avital role in embryonic development,cell growth,apoptosisand cell *** well-known function of PTEN isphosphatidylinositol-3.PI)-phosphatase,which functionsas a negative regulator of the PIkinase(PI3.)*** well established that PTEN regulates the G1-S transitionby modulating the expression of cyclin D1 and *** passage of any cell through cell cycles is subtlymodulated by a series of proteins,among which the mainplayers in animal cells include cyclins,CDKs(cyclin-de-pendent kinases,positive regulators)and CDK inhibitors(negative regulators such as p21and *** Dsare key regulators during the G1 phase and there are threetypes of cyclin Ds,D1,D2 and D3.in mammalian cells[3..Although the phenotypic analyses of single cyclin Dknockout mice revealed that each of the D type cyclinsis sufficient to drive normal development of the majority

关键词： PTEN,a general negative regulator of cyclin D expression

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,{3., Beijing 100084, china state key laboratory of Tribology Tsinghua University Beijing 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. 200603.0458)

关键词： burr molecular dynamics micro-mechanism