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Structural components of the nuclear body in nuclei of Allium cepa cells

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Cell Research 2001年第1期11卷 68-73页

作者： TAO WEI, CHANG HUI YAN, TAO CAI, SHUI HAO, ZHONG HE ZHAI (college of life sciences, peking university, beijing 100871, china) (Institute of Genetics and Cytology, Northeast Normal university, Changchun Jilin 130024, china) 1college of life sciences Peking University Beijing 100871 China 1college of life sciences Peking University Beijing 100871 China 1college of life sciences Peking University Beijing 100871 China 2Institute of Genetics and Cytology Northeast Normal University Changchun Jilin 130024 China 1college of life sciences Peking University Beijing 100871 China

Nuclear bodies have long been noted in interphase nuclei of plant cells, but their structural component, origin and fUnction are still unclear by now. The present work showed in onion cells the nuclear bodies appeared as a spherical structure about 0.3 to 0.8 μm in diameter. They possibly were formed in nucleolus and subsequently released, and entered into nucleoplasm. Observation through cytochemical staining method at the ultrastructural level codeined that nuclear bodies consisted of ribonucleoproteins (RNPs) and silver-stainable proteins. Immunocytochemical results revealed that nuclear bodies contained no DNA and ribosomal gene transcription factor (UBF). Based on these data, we suggested that nuclear bodies are not related to the ribosome or other gene transcription activities, instead they may act as subnuclear structures for RNPs transport from nucleolus to cytoplasm, and may also be involved in splicing of pre-mRNAs.

关键词： Nuclear body structural component ribonucleoproteins nucleolus Allium cepa.

Analysis of Five Differentially Expressed Gene Families in Fast Elongating Cotton Fiber

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Acta Biochimica et Biophysica Sinica 2004年第1期36卷 51-56页

作者： Jian-Xun FENG, Sheng-Jian JI, Yong-Hui SHI, Yu XU, Gang WEI, and Yu-Xian ZHU( National Laboratory of Protein Engineering and Plant Genetic Engineering, college of life sciences, peking university, beijing 100871, china ) National Laboratory of Protein Engineering and Plant Genetic Engineering College of Life Sciences Peking University Beijing 100871 China

Using the suppression subtractive hybridization method, we isolated five gene families, including proline-rich proteins (PRPs), arabinogalactan proteins (AGPs), expansins, tubulins and lipid transfer proteins (LTPs), from fast elongating cotton fiber cells. Expression profile analysis using cDNA array technology showed that most of these gene families were highly expressed during early cotton fiber developmental stages (0-20 days post anthesis, DPA). Many transcripts accumulated over 50-fold in 10 DPA fiber cells than in 0 DPA samples. The entire gene family -AGP, together with 20 individual members in other 4 gene families, are reported in cotton for the first time. Accumulation of cell wall proteins, wall loosening enzymes, microtubules and lipid transfer proteins may contribute directly to the elongation and development of fiber cells.

关键词： cotton fiber cDNA array cell elongation arabinogalactan protein lipid transfer protein

A brief account on the study of the insulin crystal structure In retrospect:Forty years after the determination of insulin’s crystal structure by Chinese scientists

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Science china(life sciences) 2010年第1期53卷 13-15页

作者： WANG Da-Cheng1 & GU XiaoCheng2 1 National Laboratory of Macromolecules,Institute of Biophysics,Chinese Academy of sciences,beijing 100101,china 2 college of life sciences,peking university,beijing 100871,china National Laboratory of Macromolecules Institute of Biophysics Chinese Academy of Sciences college of life sciences Peking University

"Standards there as high as achieved elsewhere";news delivered to the world by Science in china Approximately forty years ago when china was undergoing a period of great difficulty, Science in china,

关键词： A brief account on the study of the insulin crystal structure In retrospect

In vitro cultivation and differentiation of fetal liver stem cells from mice

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Cell Research 2005年第5期15卷 401-405页

作者： Ren Qing FENG*, Li Ying DU, Zhen Quan GUO college of life sciences, peking university, beijing 100871, china collegeoflifesciences PekingUniversityBeijing100871China

During embryonic development, pluripotent endoderm tissue in the developing foregut may adopt pancreatic fate or hepatic fate depending on the activation of key developmental regulators. Transdifferentiation occurs between hepato- cytes and pancreatic cells under specific conditions. Hepatocytes and pancreatic cells have the common endodermal progenitor cells. In this study we isolated hepatic stem/progenitor cells from embryonic day (ED) 12-14 Kun-Ming mice with fluorescence-activated cell sorting (FACS). The cells were cultured under specific conditions. The cultured cells deploy dithizone staining and immunocytochemical staining at the 15th, 30th and 40th day after isolation. The results indicated the presence of insulin-producing cells. When the insulin-producing cells were transplanted into alloxan- induced diabetic mice, the nonfasting blood glucose level was reduced. These results suggested that fetal liver stem/ progenitor cells could be converted into insulin-producing cells under specific culture conditions. Fetal liver stem/ progenitor cells could become the potential source of insulin-producing cells for successful cell transplantation therapy strategies of diabetes.

关键词： Hepatic stem/progenitor cell diabetes β-cell dithizone staining immunocytochemistry.

The CXXC finger 5 protein is required for DNA damage-induced p53 activation

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Science china(life sciences) 2009年第6期52卷 528-538页

作者： ZHANG Min1,WANG RuiPeng1,WANG YanYi 2,DIAO FeiCi1,LU Fei1,GAO Dong1,CHEN DanYing 1,ZHAI ZhongHe1 & SHU HongBing2 1 college of life sciences,peking university,beijing 100871,china 2 college of life sciences,Wuhan university,Wuhan 430072,china college of life sciences Peking University Beijing China college of life sciences Wuhan University Wuhan China

The tumor suppressor p53 is a critical component of the DNA damage response pathway that induces a set of genes responsible for cell cycle arrest,senescence,apoptosis,and DNA *** ataxia te-langiectasia mutated protein kinase(ATM) responds to DNA-damage stimuli and signals p53 stabiliza-tion and activation,thereby facilitating transactivation of p53 inducible genes and maintainence of genome *** this study,we identified a CXXC zinc finger domain containing protein termed CF5 as a critical component in the DNA damage signaling ***5 induces p53 transcriptional activity and apoptosis in cells expressing wild type p53 but not in p53-deficient *** of CF5 in-hibits DNA damage-induced p53 activation as well as cell cycle ***,CF5 physically interacts with ATM and is required for DNA damage-induced ATM phosphorylation but not its recruitment to *** findings suggest that CF5 plays a crucial role in ATM-p53 signaling in response to DNA damage.

关键词： p53 ATM DNA damage apoptosis

Recent progress in the study of intracellular toxicity of amyloid P peptide in Alzheimer's disease

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Progress in Natural Science:Materials International 2007年第3期 233-236页

作者： ZHANG Yan and YU Longchuan (college of life sciences, peking university, beijing 100871, china)

Amyloidβ(Aβ) deposition is one of the major pathological markers of Alzheimer’s disease (AD). Extracellular Afi toxi-city has been studied for a long time in AD research field. However, controversial data show that extracellular Aβload does not correlate with the dementia levels of AD patients and extracellular Aβonly induces significant cell death at non-physiological high concentrations. With the evolvement of Afi hypothesis, considerable attention has been devoted to the study of intracellular Aβtoxicity recently. Intracellular Aβinduces dramatic cell loss in AD transgenic models and in human primary neurons (at pM concentrations) through p53, Bax and caspase-6 pathways. Here, we review the generation, toxicity and possible pathways of intracellular Aβtoxicity, and discuss the implication and current knowledge of intracellular Aβin neuronal cell loss in neurodegenerative diseases.

关键词： Alzheimer’s disease amyloid P peptide neruonal loss.

N-terminal of Lprotein of vesicular stomatitis virus contains a new signal sequence

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Chinese Science Bulletin 2003年第13期48卷 1352-1357页

作者： NIE Yuchun, KE Yeyan, WANG Zai, YU Xiang, DENG Hongkui & DING Mingxiao Department of Cell Biology and Genetics, college of life sciences, peking university, beijing 100871, china Correspondence should be addressed to Ding Mingxiao (e-mail: mxding@***) Department of Cell Biology and Genetics College of Life Sciences Peking University China

The L protein (241 kD) of vesicular stomatitis virus (VSV) is the most important subunit of the replication complex. The existence of specific localization signal in the L protein was investigated by making recombinant constructs expressing truncated mutants of the L protein fused to green fluorescent protein (GFP) in transient transfection assays. The chimeric genes encoding varied N-terminal of L and GFP gene were put under the control of T7 promoter or CMV promoter. The fusion proteins were transiently expressed in BHK-21, COS-7, CHO or Hep G2 cells. When more than 120 residues were deleted or only 96 residues were kept on the N-terminal, the fusion proteins were shown to be distributed throughout the cells, cytoplasm and nucleus under the confocal microscope. However, other chimeric proteins with 120 or more amino acids were dotted and distributed in the perinuclear regions. And the fusion protein with 96120 aa has the similar distribution. A thirteen-residue peptide QGYSFLHEVDKEA (108120) was identified as localization signal, whose function would be absolutely distributed with the deficiency of D or V. Our results show that there is an independent localizing signal in N-terminal domain of L protein of VSV and this functional signal is conserved in different cell lines.

关键词： L蛋白质水泡性口膜炎病毒 VSV 基因编码绿色荧光蛋白质

Nuclear assembly of purified Crythecodinium cohnii chromosomes in cell-free extracts of Xenopus laevis eggs

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Cell Research 2000年第2期10卷 127-137页

作者： LIU XIAO LING YAN SHEN ER JIE CHEN ZHONG HEZHAI(E-mail: zhaizh@*** Tel: 86-10-62754293 Fax: 86-10-62751526)(college of life sciences, peking university, beijing 100871,china) collegeoflifesciences PekingUniversityBeijingChina.

Incubation of dinoflagellate Crythecodinium cohnii chromosomes in cytoplasmic extracts of unfertilized Xenopus laevis eggs resulted in chromosomes decondensation and recondensation, nuclear envelope assembly, and nuclear *** Crythecodinium cohnii is a kind of primitive eukaryote which possesses numerous permanently condensed chromosomes and discontinuous double-layered nuclear membrane throughout the cell cycle. The assembled nuclei, being surrounded by a continuous double membrane containing nuclear pores and the uniformly dispersed chromatin fibers are morphologically distinguishable from that of Dinoflagellate Crythecodinium cohnii. However, incubation of dinoflagellate Crythecodinium cohnii chromosomes in the extracts from dinoflagellate Crythecodinillm cohnii cells does not induce nuclear reconstitution.

关键词： Dinoflagellate Crythecodinium cohnii chromosome nuclear reconstitution cell-free system Xenopus laevis egg extracts

Methylation of Phytohormones and Plant Development

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Methylation of Phytohormones and Plant Development