检索结果-内蒙古大学图书馆

Megavesicles implicated in the rapid transport of intracisternal aggregates across the Golgi stack

CELL 2000年第3期102卷 335-348页

作者： Volchuk, A Amherdt, M Ravazzola, M Brügger, B Rivera, VM Clackson, T Perrelet, A Söllner, TH Rothman, JE Orci, L Mem Sloan Kettering Canc Ctr Cellular Biochem & Biophys Program New York NY 10021 USA Univ Geneva Sch Med Dept Morphol CH-1211 Geneva 4 Switzerland ARIAD Pharmaceut Inc Cambridge MA 02139 USA

Engineered protein aggregates ranging up to 400 nm in diameter were selectively deposited within the cis-most cisternae of the Golgi stack following a 15 degrees C block. These aggregates are much larger than the standard volume of Golgi vesicles, yet they are transported across the stack within 10 min after warming the cells to 20 degrees C. Serial sectioning reveals that during the peak of anterograde transport, about 20% of the aggregates were enclosed in topologically free "megavesicles" which appear to pinch off from the rims of the cisternae. These megavesicles can explain the rapid transport of aggregates without cisternal progression on this time scale.

关键词：生物转运细胞区室化高尔基体/代谢高尔基体/超微结构绿色荧光蛋白质类生长激素/遗传学生长激素/代谢嗜免疫剂/遗传学嗜免疫剂/代谢细胞内膜/代谢细胞内膜/超微结构发光蛋白质类/遗传学发光蛋白质类/代谢显微切片术重组蛋白质类/代谢他克莫司结合蛋白质类温度时间因素肿瘤细胞培养的人类

来源：评论

学校读者我要写书评

暂无评论

Reverse mode of the sarcoplasmic reticulum calcium pump and load-dependent cytosolic calcium decline in voltage-clamped cardiac ventricular myocytes

引用

BIOPHYSICAL JOURNAL 2000年第1期78卷 322-333页

作者： Shannon, TR Ginsburg, KS Bers, DM Loyola Univ Med Ctr Dept Physiol Maywood IL 60153 USA

We have characterized [Ca](i) decline in voltage-clamped rabbit ventricular myocytes with progressive increases in sarcoplasmic reticulum (SR) calcium load, "Backflux" through the SR calcium pump is a critical feature which allows realistically small values for SR calcium leak fluxes to be used, Total cytosolic calcium was calculated from the latter part of [Ca](i) decline using rate constants for cellular calcium buffers, Intra-SR calcium buffering characteristics were also deduced, We found that the net SR calcium pump flux and rate of [Ca](i) decline decreased as the SR free [Ca] rose, with pump parameters held constant. We have therefore characterized for the first time in intact myocytes both forward and reverse SR calcium pump kinetics as well as intra-SR calcium buffering and SR calcium leak. We conclude that the reverse flux through the SR calcium pump is an important factor in comprehensive understanding of dynamic SR calcium fluxes.

关键词：钙/代谢钙转运ATP酶类/代谢细胞培养的胞质溶胶/代谢心脏/生理学心室细胞内膜/生理学细胞内膜/超微结构动力学心肌/代谢膜片钳术肌浆网/酶学肌浆网/超微结构肌钙蛋白/代谢动物兔

来源：评论

学校读者我要写书评

暂无评论

A novel membrane-anchored rab5 interacting protein required for homotypic endosome fusion

引用

JOURNAL OF BIOLOGICAL CHEMISTRY 2000年第32期275卷 24661-24669页

作者： Hoffenberg, S Liu, X Nikolova, L Hall, HS Dai, WP Baughn, RE Dickey, BF Barbieri, MA Aballay, A Stahl, PD Knoll, BJ Baylor Coll Med Dept Med Div Pulm Houston TX 77030 USA Baylor Coll Med Dept Physiol & Mol Biophys Houston TX 77030 USA Baylor Coll Med Dept Microbiol & Immunol Houston TX 77030 USA Baylor Coll Med Dept Mol & Cellular Biol Houston TX 77030 USA Houston Vet Affairs Med Ctr Houston TX 77030 USA Washington Univ Sch Med Dept Cell Biol & Physiol St Louis MO 63110 USA

The ras-related GTPase rab5 is rate-limiting for homotypic early endosome fusion. We used a yeast two-hybrid screen to identify a rab5 interacting protein, rab5ip. The cDNA sequence encodes a ubiquitous 75-kDa protein with an N-terminal transmembrane domain (TM), a central coiled-coil structure, and a C-terminal region homologous to several centrosome-associated proteins. rab5ip lacking the transmembrane domain (rab5ipTM(-)) had a greater affinity in vitro for rab5-guanosine 5'-O-2-(thio)diphosphate than for rab5-guanosine 5'-3-O-(thio)triphosphate. In transfected HeLa cells, rab5ipTM(-) was partly cytosolic and localized (by immunofluorescence) with a rab5 mutant believed to be in a GDP conformation (GFp-rab5(G78A)) but not with GFP-rab5(Q79L), a GTPase-deficient mutant. rab5ip with the transmembrane domain (rab5ipTM(+)) was completely associated with the particulate fraction and localized extensively with GFP-rab5(wt) in punctate endosome-like structures. Overexpression of rab5ipTM(+) using Sindbis virus stimulated the accumulation of fluid-phase horseradish peroxidase by BHK-81 cells, and homotypic endosome fusion in vitro was inhibited by antibody against rab5ip. rab5ipTM(-) inhibited rab5(wt)-stimulated endosome fusion but did not inhibit fusion stimulated by rab5(Q79L). rab5ip represents a novel rab5 interacting protein that may function on endocytic vesicles as a receptor for rab5-GDP and participate in the activation of rab5.

关键词：氨基酸序列脑/代谢载体蛋白质类/化学载体蛋白质类/遗传学载体蛋白质类/代谢细胞系仓鼠亚科内颗粒/生理学内颗粒/超微结构绿色荧光蛋白质类鸟苷5'-O-(3-硫代三磷酸)/代谢鸟苷二磷酸/类似物和衍生物鸟苷二磷酸/代谢 HeLa细胞细胞内膜/生理学细胞内膜/超微结构细胞内信号肽和蛋白质类动力学发光蛋白质类/分析发光蛋白质类/遗传学膜融合/生理学膜蛋白质类/化学膜蛋白质类/遗传学膜蛋白质类/代谢分子序列数据分子量诱变定点蛋白质异戊二烯化重组融合蛋白质类/化学重组融合蛋白质类/代谢酵母菌酿酒序列比对序列同源性氨基酸硫代核苷酸类/代谢转染 rab5GTP结合蛋白质类/遗传学 rab5GTP结合蛋白质类/代谢动物人类

来源：评论

学校读者我要写书评

暂无评论

Life-cycle-dependent changes of aspartate carbamoyltransferase localization in membranes of Saccharomyces cerevisiae -: Centrifugal elutriation and ultracytochemical study

引用

FOLIA MICROBIOLOGICA 1999年第3期44卷 289-294页

作者： Vorísek, J Noaillac-Depeyre, J Denis-Duphil, M Acad Sci Czech Republ Inst Microbiol CR-14220 Prague Czech Republic Inst Biol Cellulaire & Genet UPR 9006 CNRS Lab Biol Mol Eucaryotes F-31077 Toulouse 4 France Inst Natl Sci Appl Ctr Bioingn UMR CNRS 5504 F-31077 Toulouse 4 France

Exponential culture of a Saccharomyces cerevisiae strain with overexpressed aspartate carbamoyltransferase activity (ACTase) was chilled in ice and fractionated by centrifugal elutriation to several cell populations of increasing cell mass. The enzyme activity which belong to the pyrimidine biosynthesis pathway, was detected in situ by a specific ultracytochemical reaction: the ACTase byproduct, monophosphate, was precipitated by cerium ions to cerium phosphate. During the outgrowth of nonbudding daughter cells (zero cells) the label appeared first in membranes of nuclear envelope and of mitochondria. In larger zero cells, this label appeared also in the endoplasmic reticulum, microvesicles and plasmalemma. In budding mother cells, the label was conspicuous in the whole cell-membrane complex. In most aged cells the ACTase activity was not detectable. The presence of ACTase activity in membranes of compartments conveying glycoproteins via the secretory pathway remains to be explained. To confirm the in situ detection of ACTase activity in membranes, we assayed the enzyme activity in both the 10 000 g sediment and supernatant prepared from yeast homogenate precentrifuged at 3000 g. From 23 to 43 % of ACTase activity was detected in the sediments including membranes of wild-type and ACTase-overexpressing strains.

关键词：天冬氨酸转氨甲酰酶/分离和提纯细胞区室化细胞分裂细胞分级分离细胞膜/酶学细胞膜/超微结构细胞内膜/酶学细胞内膜/超微结构细胞器/酶学细胞器/超微结构酿酒酵母菌/酶学酿酒酵母菌/生长和发育酿酒酵母菌/超微结构

来源：评论

学校读者我要写书评

暂无评论

Tim23 links the inner and outer mitochondrial membranes

引用

CELL 2000年第4期101卷 401-412页

作者： Donzeau, M Káldi, K Adam, A Paschen, S Wanner, G Guiard, B Bauer, MF Neupert, W Brunner, M Univ Munich Inst Physiol Chem D-80336 Munich Germany Univ Munich Inst Bot D-30638 Munich Germany Univ Paris 06 CNRS Ctr Genet Mol F-91190 Gif Sur Yvette France

Tim23, a key component of the mitochondrial preprotein translocase, is anchored in the inner membrane by its C-terminal domain and exposes an intermediate domain in the intermembrane space that functions as a presequence receptor. We show that the N-terminal domain of Tim23 is exposed on the surface of the outer membrane. The two-membrane-spanning topology of Tim23 is a novel characteristic in membrane biology. By the simultaneous integration into two membranes, Tim23 forms contacts between the outer and inner mitochondrial membranes. Tethering the inner membrane translocase to the outer membrane facilitates the transfer of precursor proteins from the TOM complex to the TIM23 complex and increases the efficiency of protein import.

关键词：载体蛋白质类/代谢细胞内膜/代谢细胞内膜/超微结构膜蛋白质类/代谢膜转运蛋白质类线粒体/代谢线粒体/超微结构酵母菌酿酒酿酒酵母蛋白质类动物兔

来源：评论

学校读者我要写书评

暂无评论

MOLECULAR AND ULTRASTRUCTURAL ANALYSIS OF HEAVY MEMBRANE-FRACTIONS ASSOCIATED WITH THE REPLICATION OF KUNJIN VIRUS-RNA

引用

ARCHIVES OF VIROLOGY 1992年第1-4期125卷 177-191页

作者： CHU, PWG WESTAWAY, EG MONASH UNIV DEPT MICROBIOL CLAYTON VIC 3168 AUSTRALIA

In subcellular extracts of Kunjin virus-infected cells prepared by lysis and differential centrifugation, the viral RNA polymerase, RNA and proteins were associated mainly with cytoplasm. When the cytoplasmic extract (500 g supernate) of infected cells labelled for 3 h from 24 h post-infection was further fractionated by rapid centrifugation through a sucrose density gradient, all viral products were located only in dense or "heavy membrane" fractions, which contained three types of virus-induced morphologically distinct membrane structures. These dense fractions were treated with 0.5% NP 40 and the soluble material was again centrifuged through a sucrose gradient for analyses as before. Viral RNA polymerase activity was retained and was associated with replicative intermediate RNA and some replicative form RNA in the peak enzyme fractions sedimenting at 20 S to 40 S. Enrichment of NS 3 and of the small nonstructural proteins NS 2 A and NS 2 B/NS 4 A was apparent in these fractions which were well separated from the slow sedimenting structural proteins. No detergent-resistant structures in the "heavy membrane" fractions other than ribosome-like particles were visible. The data show that the RNA polymerase complex cosedimented with virus-induced membrane structures and remained associated with specific nonstructural proteins and replicative intermediate RNA after detergent treatment.

关键词：细胞分级分离离心法梯密度黄病毒属/遗传学黄病毒属/代谢黄病毒属/生理学黄病毒属/超微结构细胞内膜/代谢细胞内膜/微生物学细胞内膜/超微结构聚乙烯二醇类/药理学 RNA复制酶/代谢 RNA 病毒/生物合成 RNA 病毒/超微结构 Vero细胞病毒复制动物

来源：评论

学校读者我要写书评

暂无评论

Membrane-bounded intratubular bodies in rat taste buds

引用

JOURNAL OF NEUROCYTOLOGY 1998年第3期27卷 157-161页

作者： Sbarbati, A Benati, D Crescimanno, C Osculati, F Univ Verona Ist Anat Umana & Istol I-37100 Verona Italy Univ Ancona Ist Morfol Umana Normale I-60128 Ancona Italy

The ultrastructural features of membrane-bounded bodies contained in the tubulo-vesicular system in the outer segment of taste bud cells are described. Each body showed a round, fusiform or oval shape, was surrounded by a trilaminar membrane and enclosed an electron dense matrix sometimes containing inclusions. These bodies were found at all ages studied. Similar structures were also found embedded in the material plugging the taste pore. Our findings suggest that these bodies could be secreted at the free surface of the cells and be involved in the concentration of divalent cations. (C) 1998 Chapman and Hall.

关键词：细胞内膜/超微结构大鼠 Wistar 味蕾/超微结构动物大鼠

来源：评论

学校读者我要写书评

暂无评论

Membrane skeleton in cultured chick cardiac myocytes revealed by high resolution immunocytochemistry

引用

HISTOCHEMISTRY AND CELL BIOLOGY 1999年第4期112卷 307-316页

作者： Larsen, TH Dalen, H Sommer, JR Boyle, R Lieberman, M Univ Bergen Expt Cardiol Unit Dept Radiol N-5021 Bergen Norway Duke Univ Med Ctr Dept Cell Biol Div Physiol Durham NC 27710 USA Duke Univ Med Ctr Dept Pathol Durham NC 27710 USA Univ Bergen Dept Pathol Gade Inst N-5021 Bergen Norway

Distribution of cytoskeletal proteins with emphasis on the membrane-cytoskeleton interface was examined in cultured cardiac myocytes. Using specific antibodies recognizing alpha-sarcomeric actin, desmin, beta-tubulin, spectrin/alpha-fodrin and ankyrin, respectively, the cellular localization of these cytoskeletal proteins was detected by laser scanning confocal microscopy. In addition, the fine filamentous structure of these proteins was identified by combining silver-enhanced immunogold labelling with electron microscopy. The latter technique employed the sequence of quick-freezing, deep-etching and rotary shadowing of the specimens. Conventional transmission electron microscopy of the spherical cardiac myocytes revealed a filamentous submembranous layer, approximately 100 nm thick. Specific immunolabelling of alpha-sarcomeric actin and spectrin/alpha-fodrin as well as ankyrin was seen beneath the plasmalemma. A three-dimensional meshwork of spectrin/alpha-fodrin was shown. Numerous desmin filaments that exhibited a tortuous course throughout the cells were also observed running in parallel with the surface in the submembranous area, whereas beta-tubulin was infrequently detected in these areas. In conclusion, the present study shows that spherical cardiac myocytes contain a distinct and complex three-dimensional membrane skeleton. Major constituents of this distinct submembranous layer were spectrin/alpha-fodrin fibres as well as actin and desmin filaments.

关键词：细胞膜/超微结构细胞培养的细胞支架蛋白质类/代谢细胞支架蛋白质类/超微结构细胞骨架/代谢细胞骨架/超微结构细胞内膜/代谢细胞内膜/超微结构显微镜检查共焦显微镜检查免疫电子心肌/细胞学心肌/代谢动物鸡胚

来源：评论

学校读者我要写书评

暂无评论

The t-SNARE AtVAM3p resides on the prevacuolar compartment in arabidopsis root cells

引用

PLANT PHYSIOLOGY 1999年第3期121卷 929-938页

作者： Sanderfoot, AA Kovaleva, V Zheng, HY Raikhel, NV Michigan State Univ Dept Energy Plant Res Lab E Lansing MI 48824 USA

Protein cargo is trafficked between the organelles of the endomembrane system inside transport vesicles, a process mediated by integral membrane proteins called SNAREs (soluble N-ethylmaleimide sensitive factor attachment protein receptors) that reside on the surface of the vesicle (v-SNAREs) and target membrane (t-SNAREs). In examining transport of cargo between the trans-Golgi network and the vacuole in Arabidopsis, we have previously characterized AtPEP12p as a t-SNARE residing on the prevacuolar compartment and AtVTI1a as a v-SNARE that interacts with AtPEP12p. Recently, we have begun to characterize AtVAM3p, another Arabidopsis t-SNARE that shows high sequence homology to AtPEP12p. We have found that AtVTI1a also interacts with AtVAM3p, suggesting a role for this t-SNARE in post-Golgi trafficking. AtVAM3p has been suggested to localize to the vacuolar membrane in Arabidopsis cells;however, using specific antisera and expression of epitope-tagged versions of each t-SNARE, we have discovered that AtVAM3p is found on the same prevacuolar structure as AtPEP12p in Arabidopsis root cells.

关键词：拟南芥属/生理学拟南芥属/超微结构拟南芥蛋白质类细胞内膜/超微结构膜蛋白质类/分析种系发生植物蛋白质类/分析植物蛋白质类/遗传学植物根/超微结构 Qa-SNARE蛋白质类空泡/生理学空泡/超微结构人类

来源：评论

学校读者我要写书评

暂无评论

Activation of flavin-containing oxidases underlies light-induced production of H₂O₂ in mammalian cells

引用

PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 1999年第11期96卷 6255-6260页

作者： Hockberger, PE Skimina, TA Centonze, VE Lavin, C Chu, S Dadras, S Reddy, JK White, JG Northwestern Univ Sch Med Dept Physiol Chicago IL 60611 USA Northwestern Univ Sch Med Dept Pathol Chicago IL 60611 USA Univ Wisconsin Integrated Microscopy Resource Madison WI 53706 USA

Violet-blue light is toxic to mammalian cells, and this toxicity has been linked with cellular production of H2O2. In this report, we show, that violet-blue light, as well as UVA, stimulated H2O2 production in cultured mouse, monkey, and human cells. T-Ve found that H2O2 originated in peroxisomes and mitochondria, and it was enhanced in cells overexpressing flavin containing oxidases. These results support the hypothesis that photoreduction of flavoproteins underlies light-induced production of H2O2 in cells. Because H2O2 and its metabolite, hydroxyl radicals, can cause cellular damage, these reactive oxygen species may contribute to pathologies associated with exposure to UVA, violet, and blue light. They may also contribute to phototoxicity often encountered during light microscopy. Because multiphoton excitation imaging with 1,047-nm wavelength prevented light-induced H2O2 production in cells, possibly by minimizing photoreduction of flavoproteins, this technique may be useful for decreasing phototoxicity during fluorescence microscopy.

关键词： 3T3细胞酰基CoA氧化酶细胞系黑长尾猴细胞质/辐射效应细胞质/超微结构酶激活/辐射效应过氧化氢/代谢细胞内膜/辐射效应细胞内膜/超微结构光微体/辐射效应微体/超微结构线粒体/辐射效应线粒体/超微结构模型化学氧化还原酶类/代谢氧化还原酶类/辐射效应重组蛋白质类/代谢重组蛋白质类/辐射效应转染紫外线黄嘌呤氧化酶/代谢黄嘌呤氧化酶/辐射效应动物人类小鼠大鼠

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：