检索结果-内蒙古大学图书馆

Tau phosphorylation at serine 396 and serine 404 by human recombinant tau protein kinase II inhibits tau's ability to promote microtubule assembly

引用

JOURNAL OF BIOLOGICAL CHEMISTRY 2000年第32期275卷 24977-24983页

作者： Evans, DB Rank, KB Bhattacharya, K Thomsen, DR Gurney, ME Sharma, SK Pharmacia Corp Prot Sci Kalamazoo MI 49007 USA

In Alzheimer's disease, hyperphosphorylated tau is an integral part of the neurofibrillary tangles that form within neuronal cell bodies and fails to promote microtubule assembly, Dysregulation of the brain-specific tau protein kinase II is reported to play an important role in the pathogenesis of Alzheimer's disease (Patrick, G. N., Zukerberg, L., Nikolic, M., De La Monte, S., Dikkes, P., and Tsai, L.-H, (1999) Nature 402, 615-622), We report here that in vitro phosphorylation of human tau by human recombinant tau protein kinase II severely inhibits the ability of tau to promote microtubule assembly as monitored by tubulin polymerization. The ultrastructure of tau-mediated polymerized tubulin was visualized by electron microscopy and compared with phosphorylated tau, Consistent with the observed slower kinetics of tubulin polymerization, phosphorylated tau is compromised in its ability to generate microtubules. Moreover, me show that phosphorylation of microtubule-associated tau results in tau's dissociation from the microtubules and tubulin depolymerization, Mutational studies with human tau indicate that phosphorylation by tau protein kinase II at serine 396 and serine 404 is primarily responsible for the functional loss of tau-mediated tubulin polymerization. These in vitro results suggest a possible role for tau protein kinase II-mediated tau phosphorylation in initiating the destabilization of microtubules.

关键词：氨基酸取代细胞系昆虫动力学微管/生理学微管/超微结构诱变定点磷酰化蛋白质丝氨酸苏氨酸激酶/代谢重组蛋白质类/代谢丝氨酸底物特异性转染微管蛋白/生理学微管蛋白/超微结构 tau蛋白质类/拮抗剂和抑制剂 tau蛋白质类/化学 tau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

REGULATION OF TUBULIN EXPRESSION THROUGH CELL-CYCLE

引用

ANNALS OF THE NEW YORK ACADEMY OF SCIENCES 1975年第JUN30期253卷 292-303页

作者： KLEVECZ, RR FORREST, GL CITY HOPE NATL MED CTR DEPT CELL BIOL DUARTE CA 91010 USA

来源：评论

学校读者我要写书评

暂无评论

Syntaxin 1 interacts with the L_D subtype of voltage-gated Ca²⁺ channels in pancreatic β cells

引用

PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 1999年第18期96卷 10164-10169页

作者： Yang, SN Larsson, O Bränström, R Bertorello, AM Leibiger, B Leibiger, IB Moede, T Köhler, M Meister, B Berggren, PO Karolinska Hosp Karolinska Inst Rolf Luft Ctr Diabet Res Dept Mol Med S-17176 Stockholm Sweden Karolinska Hosp Karolinska Inst Dept Neurosci S-17176 Stockholm Sweden

Interaction of syntaxin 1 with the alpha(1D) subunit of the voltage-gated L type Ca2+ channel was investigated in the pancreatic beta cell, Coexpression of the enhanced green fluorescent protein-linked alpha(1D) subunit with the enhanced blue fluorescent protein-linked syntaxin 1 and Western blot analysis together with subcellular fractionation demonstrated that the alpha(1D) subunit and syntaxin 1 were colocalized in the plasma membrane. Furthermore, the alpha(1D) subunit was coimmunoprecipitated efficiently by a polyclonal antibody against syntaxin 1, Syntaxin 1 also played a central role in the modulation of L type Ca2+ channel activity because there was a faster Ca2+ current run-down in cells incubated with antisyntaxin 1 compared with controls. In parallel, antisyntaxin 1 markedly reduced insulin release in both intact and permeabilized cells, subsequent to depolarization with K+ or exposure to high Ca2+, Exchanging Ca2+ for Ba2+ abolished the effect of antisyntaxin 1 on both Ca2+ channel activity and insulin exocytosis, Moreover, antisyntaxin 1 had no significant effects on Ca2+-independent insulin release trigged by hypertonic stimulation, This suggests that there is a structure-function relationship between the air, subunit of the L type Ca2+ channel and the exocytotic machinery in the pancreatic beta cell.

关键词：抗体单克隆/药理学抗原表面/免疫学抗原表面/分离和提纯抗原表面/代谢钙/代谢钙通道/遗传学钙通道/分离和提纯钙通道/生理学钙通道 L型细胞膜/生理学细胞膜/超微结构离心法梯密度胞吐作用/生理学绿色荧光蛋白质类胰岛/生理学发光蛋白质类/遗传学大分子物质小鼠肥胖神经组织蛋白质类/免疫学神经组织蛋白质类/分离和提纯神经组织蛋白质类/代谢膜片钳术重组融合蛋白质类/代谢突触融合蛋白质1 微管蛋白/免疫学微管蛋白/生理学动物小鼠

来源：评论

学校读者我要写书评

暂无评论

Theoretical evidence that more microtubules reach the cortex at the pole than at the equator during anaphase in sea urchin eggs

引用

ACTA BIOTHEORETICA 2003年第1期51卷 43-53页

作者： Yoshigaki, T Nishi Tokyo Tokyo Japan

Astral microtubules are rapidly elongated during anaphase and telophase in sea urchin eggs. The number of microtubules extending to the cell surface was calculated with a computer. For the calculations, microtubules were assumed to radiate from the astral center uniformly over angles. Although microtubules from two asters freely overlapped around the equator, the number per the unit area, i.e. the surface density, was larger in the polar region than in the equatorial region. The ratio of the theoretically calculated numbers in the two regions was close to the ratio obtained from the ultrastructural observations by Asnes and Schroeder in 1979. When counted in the longitudinal section including two astral centers, the microtubule number was a little larger in the equatorial region than in the polar region. However, the numbers do not represent the surface density because the two-dimensional section contains only a small portion of all the microtubules spreading in the three-dimensional space. The fluorescence image for tubulin, in most cases, provides the microtubule distribution in the longitudinal section. Therefore, from such an image, we cannot judge whether the surface density of astral microtubules is larger at the pole or at the equator.

关键词：后期/生理学计算机模拟图像处理计算机辅助显微镜检查荧光微管/生理学微管/超微结构模型生物学卵子/生理学卵子/超微结构海胆纲统计学分布微管蛋白/生理学微管蛋白/超微结构动物女(雌)性

来源：评论

学校读者我要写书评

暂无评论

Hematopoietic-specific β1 tubulin participates in a pathway of platelet biogenesis dependent on the transcription factor NF-E2

引用

BLOOD 2000年第4期96卷 1366-1373页

作者： Lecine, P Italiano, JE Kim, SW Villeval, JL Shivdasani, RA Dana Farber Canc Inst Dept Adult Oncol Boston MA 02115 USA Dana Farber Canc Inst Dept Canc Biol Boston MA 02115 USA Brigham & Womens Hosp Dept Med Boston MA 02115 USA Harvard Univ Sch Med Boston MA USA

The cellular and molecular bases of platelet release by terminally differentiated megakaryocytes represent important questions in cell biology and hematopoiesis. Mice lacking the transcription factor NF-E2 show profound thrombocytopenia, and their megakaryocytes fail to produce proplatelets, the microtubule-based precursors of blood platelets. Using mRNA subtraction between normal and NF-E2-deficient megakaryocytes, cDNA was isolated encoding beta 1 tubulin, the most divergent beta 1 tubulin isoform. In NF-E2-deficient megakaryocytes, beta 1 tubulin mRNA and protein are virtually absent. The expression of beta 1 tubulin Is exquisitely restricted to platelets and megakaryocytes, where it appears late in differentiation and localizes to microtubule shafts and coils within proplatelets. Restoring NF-E2 activity in a megakaryoblastic cell line or in NF-E2-deficient primary megakaryocytes rescues the expression of beta 1 tubulin. Reexpressing beta 1 tubulin in isolation does not, however, restore proplatelet formation in the defective megakaryocytes, indicating that other critical factors are required;indeed, other genes identified by mRNA subtraction also encode structural and regulatory components of the cytoskeleton. These findings provide critical mechanistic links between NF-E2, platelet formation, and selected microtubule proteins, and they also provide novel molecular insights into thrombopoiesis. (Blood. 2000;96:1366-1373) (C) 2000 by The American Society of Hematology.

关键词：血小板/细胞学血小板/生理学细胞分化/生理学细胞谱系/生理学 DNA结合蛋白质类/生理学红系细胞特异性DNA结合因子类血细胞生成/生理学 NF-E2转录因子 NF-E2转录因子 p45亚基核蛋白质类/生理学 RNA 信使/生物合成阻遏蛋白质类/生理学转录因子/生理学微管蛋白/生理学动物小鼠

来源：评论

学校读者我要写书评

暂无评论

Unique processing pathways within recipient antigen-presenting cells determine IgG immunity against donor platelet MHC antigens

引用

BLOOD 2000年第5期95卷 1735-1742页

作者： Bang, KWA Speck, ER Blanchette, VS Freedman, J Semple, JW St Michaels Hosp Dept Lab Med & Pathobiol Toronto ON M5B 1W8 Canada Hosp Sick Children Div Hematol Oncol Toronto ON M5G 1X8 Canada Univ Toronto Hosp Sick Children Div Hematol Oncol Dept Pharmacol Toronto ON Canada Univ Toronto Hosp Sick Children Div Hematol Oncol Dept Med & Pediat Toronto ON Canada Toronto Platelet Immunobiol Grp Toronto ON Canada

Recipient IgG immunity against leukoreduced donor platelets is dependent on indirect T-cell allorecognition and is suppressed in vivo by inhibitors (aminoguanidine, AMG) of inducible nitric oxide synthase (iNOS), To examine recipient processing pathways of donor platelet antigens, enriched macrophages (antigen-presenting cells [APC]) from BALB/c (H-2(d)) mice were pulsed with allogeneic C57BL/6 (H-2(b)) platelets and transfused weekly into naive BALB/c mice. Platelet-pulsed APC stimulated IgG antidonor antibody production in 45% of recipients by the second transfusion and in 100% by the sixth transfusion;this response was enhanced by pulsing in the presence of interferon-gamma. By the sixth transfusion, high-titer IgG1 (mean titer 4990) and IgG2a (1933) isotypes specific for donor major histocompatibility complex (MHC) class I antigens were detected. Platelet pulsing in the presence of AMG or colchicine significantly inhibited the ability of APC to stimulate IgG alloantibodies;only 50% (P < .005) and 20% (P < .0001) of recipients, respectively, produced antibodies by the sixth transfusion. AMG inhibition was reversed by the addition of L-arginine, the substrate for iNOS, In contrast, pulsing in the presence of chloroquine, the proteasome inhibitory peptide MG115, or Brefeldin A enhanced APC immunity (70-100% of recipients antibody positive by the second transfusion [P < .05]);these agents allowed the pulsed APC to stimulate IgG2a but inhibited IgG1 production and this correlated with a reduction in serum interleukin (IL)-4 levels, The results suggest that for donor platelet antigens to stimulate IgG alloantibodies, recipient APC use the essential generation of nitric oxide and a noncytosolic, pH-independent processing pathway, which can be exploited as an effective immunotherapy target to further inhibit alloimmunization against leukoreduced platelets, (C) 2000 by The American Society of Hematology.

关键词：氯化铵/药理学抗体特异性抗原呈递抗原呈递细胞/药物作用抗原呈递细胞/免疫学抗原呈递细胞/代谢供血者血小板/药物作用血小板/免疫学布雷菲德菌素A/药理学氯喹/药理学秋水仙碱/药理学胞质溶胶/代谢胞吞作用/药物作用内颗粒/药物作用内颗粒/代谢酶激活 H-2抗原/免疫学 H-2抗原/代谢免疫球蛋白G/生物合成免疫球蛋白G/免疫学白细胞介素4/血液同种抗体/生物合成同种抗体/免疫学亮肽菌素类/药理学巨噬细胞/药物作用巨噬细胞/免疫学巨噬细胞/代谢小鼠近交BALBC 小鼠近交C57BL 微管/生理学一氧化氮/生理学一氧化氮合酶/代谢一氧化氮合酶Ⅱ型血小板输注 T淋巴细胞辅助诱导/免疫学微管蛋白/生理学动物女(雌)性小鼠

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：