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Identification of AtENT3 as the main transporter for uridine uptake in Arabidopsis roots

Cell Research 2006年第4期16卷 377-388页

作者： Kun Ling Chen~(1,2,*) Min Xin Xu~(2,3,*) Guang Yong Li~(2,3,*) Hui Liang~2 Zong Liang Xia~(2,3) Xin Liu~2 Ji Shu Zhang~1 Ai Min Zhang~2 Dao Wen Wang~2 ~1school of Life sciences,Northwest Agricultural and Forestry University,Yangling 712100,china ~2Center for Plant Gene Research(beijing)and the State Kev Laboratory of Plant Cell and Chromosome Engineering,Institute of Genetics and Developmental Biology,chinese academy of sciences,Datun road,Chaovang district,beijing 100101,china ~3graduate school of the chinese academy of sciences,yuquan road,shijingshan district,beijing 100039,china school of Life sciences Northwest Agricultural and Forestry University Yangling China Center for Plant Gene Research (beijing) and the State Key Laboratory of Plant Cell and Chromosome Engineering Institute of Genetics and Developmental Biology Chinese Academy of Sciences Datun Road Chaoyang District Beijing China graduate school of the chinese academy of sciences Yuquan Road Shijingshan District Beijing China

Previous studies have shown that Arabidopsis equilibrative nucleoside transporters （AtENTs） possess transport activitieswhen produced in yeast cells and are differentially expressed in Arabidopsis ***,we report further analysis onthe nucleoside transport activities and transcriptional patterns of AtENT *** recombinant proteins of AtENTs3,6,and 7,but not those of AtENTs 1,2,4,and 8,were found to transport thymidine with high *** to previ-ous suggestion that AtENT1 may not transport uridine,this work showed that recombinant AtENT1 was a pH-dependentand high-affinity transporter of *** grown on MS plates,the AtENT3 knockout plants were more tolerant tothe cytotoxic uridine analog 5-fluorouridine than wild-type plants and the knockout plants ofAtENT 1 or ***-sistent with this observation,the AtENT3 knockout line exhibited a significantly decreased ability to take up [3H]uridinevia the roots when compared with wild-type plants and the plants with mutated AtENT 1 or *** indicates thatAtENT3,but not AtENTs 1 and 6,is the main transporter for uridine uptake in Arabidopsis *** transcription ofAtENTs 1,3,4,6,7,and 8 was regulated in a complex manner during leaf development and *** contrast,thesix AtENT members were coordinately induced during seed *** work provides new information on thetransport properties of recombinant AtENT proteins and new clues for future studies of the in vivo transport activitiesand physiological functions of the different ENT proteins in Arabidopsis plants.

关键词： Arabidopsis equilibrative nucleoside transporter expression pattern nucleoside transport functional analysis

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Effects of cosmological constant on motion of UHECR particles

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Science china(Physics,Mechanics & Astronomy) 2005年第1期48卷 44-56页

作者： CHEN Shaoxia & CHANG Zhe Institute of High Energy Physics, chinese academy of sciences, beijing 100039, china graduate school of chinese academy of sciences, beijing 100039, china Institute of High Energy Physics Chinese Academy of Sciences Beijing 100039 China graduate school Chinese Academy of Sciences Beijing 100039 China

Recent astronomical observations manifest that about two-thirds of the whole energy in the Universe is contributed by a small positive cosmological constant A (> 0). Then, an asymptotically de Sitter spacetime is premised naturally. However, physics in the de Sitter spacetime is very different from that in the Minkowski spacetime. As the first step, a covariant formalism of the kinematics in the de Sitter spacetime is presented here. By solving exactly the equations of motion for a field, we obtain the dispersion relation of a free particle. It is noticed that the dispersion relation is dependent on the degree of freedom of angular momentum of the particle. We show the threshold anomaly of the ultra high energy cosmic ray disappears naturally in the framework of the de Sitter kinematics.

关键词： ultrahigh energy cosmic ray, cosmological constant, curved spacetime.

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Molecular and functional characterization of sulfiredoxin homologs from higher plants

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Cell Research 2006年第3期16卷 287-296页

作者： Xian Peng Liu~(1,2) Xue Ying Liu~(1,2) Juan Zhang~(1,2) Zong Liang Xia~(1,2) Xin Liu~1 Huan Ju Qin~1 Dao Wen Wang~11 The State Key Laboratory of Plant Cell and Chromosome Engineering,Institute of Genetics and Developmental Biology,chinese academy of sciences,Datun road,Chaoyang district,beijing 100101,china 2 graduate University of chinese academy of sciences,yuquan road,shijingshan district,beijing 100039,china The State Key Laboratory of Plant Cell and Chromosome Engineering Institute of Genetics and Developmental Biology Chinese Academy of Sciences Chaoyang District China graduate University of chinese academy of sciences Shijingshan District China

By reducing cysteine-sulfinic acid in oxidized peroxiredoxin,sulfiredoxin (Srx) plays an important role in oxidationstress resistance in yeast and human ***,we report the first molecular and functional characterization of Srxhomolog from higher *** analysis revealed the presence of potential Srx encoding sequences in bothmonocot and dicot plant *** plant Srx proteins exhibited significant identities to their orthologs from yeastand human,and contained the conserved signature sequence and residues essential for ***,unlike yeastand human orthologs,plant Srxs were all predicted to possess chloroplast transit peptide in their primary *** proteins from Arabidopsis and rice (designated as AtSrx and OsSrx,respectively) complemented functional defi-ciency of Srx in the SRXl deletion yeast cells.A GFP fusion protein of AtSrx was targeted to chloroplast in Arabidopsismesophyll *** transcription occurred in both vegetative and reproductive organs,and the highest transcriptlevel was detected in *** oxidation stress,AtSrx transcript level was substantially increased,which paralleledwith enhanced transcription of 2-Cys peroxiredoxins that have been found essential in maintaining chloroplast *** addition to oxidation stress,osmotic/water deficit or cold treatments also raised AtSrx transcript ***-sistent with above findings,the knock-out mutant of AtSrx was significantly more susceptible to oxidation stress thanwild type Arabidopsis *** together,the results of this work indicate the existence of functional Srx homolog inhigher plants that is essential for plants to cope with oxidation stress.

关键词： Arabidopsis sulfiredoxin chloroplast reactive oxygen species stress

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Recent advances in the data analysis method of functional magnetic resonance imaging and its applications in neuroimaging

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Progress in Natural Science:Materials International 2006年第8期16卷 785-795页

作者： TIAN Jie, YANG Lei and HU Jin (Institute of Automation, chinese academy of sciences, beijing 100080, china graduate school of chinese academy of sciences, beijing 100039, china) Institute of Automation Chinese Academy of Sciences Beijing 100080 China graduate school of chinese academy of sciences Beijing 100039 China

Functional magnetic resonance imaging (fMRI) has opened a new area to explore the human brain. The fMRI can reveal the deep insights of spatial and temporal changes underlying a broad range of brain function, such as motor, vision, memory and emotion, all of which are helpful in the clinical investigation. In this paper, we introduce some recent-developed algorithms for fMRI signal detection such as model-driven method (general linear model, deconvolution model, non-linear model, etc. ) and data-driven method (principle component analysis, independent component analysis, self-organization mapping, clustered constrained non-negative matrix factorization, etc. ). We also propose several important applications of neuroimaging and point out their shortcomings and future perspectives.

关键词： fMR1 data analysis neuroimaging.

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Mass Spectrometric Evidence of Heparin Disaccharides for the Catalytic Characterization of A Novel Endolytic Heparinase

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Acta Biochimica et Biophysica Sinica 2004年第12期36卷 840-844页

作者： Yapeng CHAO1,3, Shaoxiang XIONG2, Xiulan CHENG1, and Shijun QIAN1* 1Institute of Microbiology, chinese academy of sciences, beijing 100080, china 2Center of Mass Spectrometry, Institute of Chemistry, chinese academy of sciences, beijing 100080, china 3graduate school of the chinese academy of sciences, beijing 100039, china Institute of Microbiology Chinese Academy of SciencesBeijing 100080 China graduate school of the chinese academy of sciencesbeijing 100039 China Center of Mass Spectrometry Institute of Chemistry Chinese Academy of SciencesBeijing 100080 China

Heparinase from different sources can eliminate heparin or/and heparan sulfate into various low-molecular weight heparins with different characteristics. Porcine intestinal mucosa heparin was de- graded into a series of oligosaccharides by a novel heparinase from the species Sphingobacterium. Disaccha- ride components from the digests were separated and purified by ultrafiltration and HPLC. Five major peaks appeared as three types according to their retention time. The mass spectrometry of peak I mainly gave the non-sulfated disaccharide with the mass of 379 Da. Peak II and III were indicated as two major monosulfated disaccharides with molecular mass of 417 and 459 Da respectively. Moreover, the peak III represented an N- acetyl disaccharide. Both peak IV and V showed the same mass of 496 Da, hinting that they were disulfate- substituted disaccharides. No trisulfate-substituted disaccharides were detected in the mixture of the heparin digest though they were abundant in the heparin structure. The results revealed that the heparinase might specifically cut the sites with low sulfated domain in heparin.

关键词： electrospray ionization-mass spectrometry heparin disaccharides heparinase high perfor- mance liquid chromatography Sphingobacterium sp.

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Reconstruction of temperature series in china for the last 5000 years

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Progress in Natural Science:Materials International 2006年第8期16卷 838-845页

作者： GE Quansheng, WANG Shunbing and ZHENG Jingyun (Institute of Geographical sciences and Natural Resources Research, chinese academy of sciences, beijing 100101, china graduate school of the chinese academy of sciences, beijing 100039, china) Institute of Geographical sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China graduate school of the chinese academy of sciences Beijing 100039 China

A temperature series with a 100 year resolution for the last 5000 years in china has been reconstructed by using 31 longterm temperature proxy series selected from recent publications in the last 20 years. The proxy records include pollens, stalagmites, lake-sediments, peat, ice cores and historical documents. The result reveals that in the millennial scale temperature variation it was warm in 3050-250 BC and it was cold in 250 BC-1950 AD. In the above two periods there were many stages of sub-scale temperature fluctuations. The result also shows an obvious temperature discrepancy on the century to multi-century scale between the Eastern Monsoon Region, the Qinghai-Tibet Region and the Northwestern Region in 2850 BC, 2350 BC, 1350 BC, 950-350 BC, 50-250 AD, and 550 AD. A comparison between the reconstructed series of this paper and some North Hemisphere temperature series indicates that in the longterm scale change, the temperature change in china is in phrase with that of the Northern Hemisphere during the last 5000 years, while on the century to multi-century scale there are differences at the beginning and end times, which may imply that temperature change does not occur simultaneously in different regions.

关键词： temperature series the last 5000 years china.

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AtbHLH29 of Arabidopsis thaliana is a functional ortholog of tomato FER involved in controlling iron acquisition in strategy I plants

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Cell Research 2005年第8期15卷 613-621页

作者： You Xi YUAN1,2, Juan ZHANG1,2, Dao Wen WANG1, Hong Qing LING1,* 1The State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, chinese academy of sciences, Datun road, Chaoyang district, beijing 100101, china 2graduate school of the chinese academy of sciences, yuquan road, shijingshan district, beijing 100039, china The State Key Laboratory of Plant Cell and Chromosome Engineering Institute of Genetics and Developmental Biology Chinese Academy of Sciences Beijing China graduate school of the chinese academy of sciences Beijing China

AtbHLH29 of Arabidopsis, encoding a bHLH protein, reveals a high similarity to the tomato FER which is proposed as a transcriptional regulator involved in controlling the iron deficiency responses and the iron uptake in tomato. For identification of its biological functions, AtbHLH29 was introduced into the genome of the tomato FER mutant T3238fer mediated by Agrobacterium tumefaciencs. Transgenic plants were regenerated and the stable integration of AtbHLH29 into their genomes was confirmed by Southern hybridization. Molecular analysis demonstrated that expression of the exogenous AtbHLH29 of Arabidopsis in roots of the FER mutant T3238fer enabled to complement the defect functions of FER. The transgenic plants regained the ability to activate the whole iron deficiency responses and showed normal growth as the wild type under iron-limiting stress. Our transformation data demonstrate that AtbHLH29 is a functional ortholog of the tomato FER and can completely replace FER in controlling the effective iron acquisition in tomato. Except of iron, FER protein was directly or indirectly involved in manganese homeostasis due to that loss functions of FER in T3238fer resulted in strong reduction of Mn content in leaves and the defect function on Mn accumulation in leaves was complemented by expression of AtbHLH29 in the transgenic plants. Identification of the similar biological functions of FER and AtbHLH29, which isolated from two systematically wide-diverged “strategy I” plants, suggests that FER might be a universal gene presented in all strategy I plants in controlling effective iron acquisition system in roots.

关键词： tomato AtbHLH29 iron uptake Arabidopsis FER plant nutrition.

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Identification of novel SINEs from Cyprinidae and their evolutionary significance

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Progress in Natural Science:Materials International 2007年第3期17卷 270-279页

作者： HAN Yawei, HE Slumping and CHEN Yiyu ( Institute of Hydrobiology, chinese academy of sciences, Wuhan 430072, china. graduate school, chinese academy of sciences, beijing 100039, china) Institute of Hydrobiology Chinese Academy of Sciences Wuhan 430072 China graduate school Chinese Academy of Sciences Beijing 100039 China

Short interspersed nuclear elements (SINEs) are widespread among eukaryotic genomes. They are repetitive DNA sequences that have been amplified by retrotransposition. In this study, a class of SINEs were isolated from the Opsariichthys bidens genome, and named Opsar. Sequence analysis confirmed that Opsar is a new class of typical SINEs derived from tRNA molecules. With the tRNA-derived region of Opsar and through BLASTN search, we further identified Zb-SINEs from the zebrafish genome, which includes two groups: Zb-SINE-A and Zb-SINE-B. The Zb-SINE-A. group comprises subfamilies of -Al--A5, and the Zb-SINE-B group is a dimer of the tRNA -derived region and shares a similar dimeric composition to Alu. Zb-SINEs are composed of three distinct regions: a 5’ end tRNA-derived region, a tRNA-unrelated region and a 3’ end AT-rich region. The flanking regions are AT rich. The average length of Zb-SINEs elements is about 340 bp. Zb-SINEs account for as much as 0.1 % of the whole zebrafish genome. About 70% of the Zb-SINEs are on chromosomes 11, 18, and 19. These Zb-SINEs were characterized by PCR and dot hybridization. The distribution pattern of Zb-SINEs in genome strongly supports the master genes model. The tRNA-derived regions of Opsar and Zb-SINEs were compared with the tRNAAla gene, and they showed 76% similarity, indicating that Opsar and Zb-SINEs originated from an inactive tRNA sequence or a tRNA -like sequence. In view of the evolutionary status of zebrafish in the Cyprinidae, we deduced that Zb-SINEs were a very old class of interspersed sequences.

关键词： short interspersed nuclear elements (SINEs) master gene model Opsar Zb-SINEs and Cyprinidae.

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Twistor bundle theory and its application

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Science china Mathematics 2004年第4期47卷 605-616页

作者： PENG Chia-Kuei & TANG ZizhouDepartment of Mathematics, graduate school of chinese academy of sciences, beijing 100039, china Department of Mathematical sciences, Tsinghua University, beijing 100084, china Department of Mathematics Graduate School of Chinese Academy of Sciences Beijing China Department of Mathematical sciences Tsinghua University Beijing China

Over an oriented even dimensional Riemannian manifold(M 2m ,ds2 ), in terms of the Levi-Civita connection form Ω and the canonical form Θ on the bundle of positive orthonormal frames, we give a detailed description of the twistor bundle Гm = SO(2m)/U(m)? J +(@#@ M,ds2 ) →M. The integrability on an almost complex structureJ compatible with the metric and the orientation, is shown to be equivalent to the fact that the corresponding cross section of the twistor bundle is holomorphic with respect toJ and the canonical almost complex structureJ 1 onJ +(M,ds2 ), by using moving frame theory. Moreover, for various metrics and a fixed orientation onM, a canonical bundle isomorphism is established. As a consequence, we generalize a celebrated theorem of LeBrun.

关键词： almost complex structure, integrability, twistor bundle.

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An improved method for evaluating the seasonal variability of total suspended sediment flux field in the Yellow and East china Seas

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International Journal of Sediment Research 2011年第1期26卷 1-14页

作者： PANG Chongguang~1,YU Wei~2,YANG Yang~3,and HAN Danxiu~4 Institute of Oceanology,chinese academy of sciences,Qingdao 266071,china, 2 Institute of Oceanology,chinese academy of sciences,Qingdao 266071,china,graduate school of chinese academy of sciences,beijing 100039,china 3 Institute of Oceanology,chinese academy of sciences,Qingdao 266071,china,graduate school of chinese academy of sciences,beijing 100039,china 4 china University of Petroleum,beijing 102249,china Doctor Researcher Institute of Oceanology Chinese Academy of Sciences Qingdao 266071 China Institute of Oceanology Chinese Academy of Sciences Qingdao 266071 China Graduate School of Chinese Academy of Sciences Beijing 100039 China china University of Petroleum Beijing 102249 China

The suspended sediment flux field in the Yellow and East china Seas(YECS) displays its seasonal variability.A new method is introduced in this paper to obtain the flux field via retrieval of ocean color remote sensing data,statistical analysis of historical suspended sediment concentration data,and numerical simulation of three-dimensional(3D) flow *** components of the sediment flux field include(i) surface suspended sediment concentration inverted from ocean color remote sensing data;(ii) vertical distribution of suspended sediment concentration obtained by statistical analysis of historical observation data;and(iii) 3D flow field modeled by a numerical *** the improved method,the 3D suspended sediment flux field in the YECS has been *** comparison with the suspended sediment flux field solely based on the numerical simulation of a suspended sediment transport model,the suspended sediment flux field obtained by the improved method is found to be more *** 3D suspended sediment flux field from ocean colour remote sensing and in situ observation are more closer to the ***,by quantitatively analyzing the newly obtained suspended sediment flux field,the quantity of sediment erosion and deposition within the different regions can be *** sediment exchange between the Yellow Sea and the East china Sea can be *** mechanism of suspended sediment transport in the YECS can be better *** particular,it is suggested that the long-term transport of suspended sediment is controlled mainly by the circulation pattern,especially the current in winter.

关键词： Suspended sediment flux field Seasonal variability Yellow and East china Seas Regression equation Numerical simulation

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