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Roles of GTP-binding proteins in dynamics of secretory granules in human neutrophils

GTP 结合蛋白在人中性粒细胞分泌颗粒动力学中的作用

基本信息

批准号：
07807101
负责人：
KOBAYASHI Toshihiro
金额：
$ 1.28万
依托单位：
Kochi Medical School
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07807101/
关键词：
neutrophils signal transduction GTP-binding proteins NADPH oxidase alkaline phosphatase

项目摘要

Human neutrophils possess alkaline phosphatase-containing intracellular granules which are up-regulated to the cell surface upon stimulation (Kobayashi and Robinson. 1991, J.Cell Biol.113 : 743-756). The mechanisms of the intracellular dynamics of these granules has not fully elucidated. The aim of the present study is to investigate the participation of GTP-binding proteins in reorganization and exocytosis of the alkaline phosphatase-containing granules using electropermeabilized cells. In biochemical assays, intact neutrophils showed the up-regulation of alkaline phosphatase activity to the cell surface upon stimulation with AIF_4^- and N-formy1 peptide. This up-regulation was inhibited by the treatment of cells with pertussis toxin or botulinum toxin. Alkaline phosphatase activity was also up-regulated in electropermeabilized cells stimulated with GTPgammaS,but not with GDPbetaS.In cytochemical studies, alkaline phosphatase-containing granules were localized dispersedly throughout the cytoplasm in unstimulated electromeabilized neutrophils. Upon stimulation with GTPgammaS,but not with GDPbetaS,these granules fused to from elongated tubular structures which were associated with the plasma membrane. Nocodazole perturbed the reorganization of the alkaline phosphatase-containing granules upon stimulation with GTPgammaS.Results from this study indicate that GTP-binding proteins participate in reorganization and exocytosis of the alkaline phosphatase-containing granules which are associated with the microtubules in electropermeabilized human neutrophils.

人嗜中性粒细胞具有含有碱性磷酸酶的细胞内颗粒，其在刺激后上调至细胞表面(Kobayashi和Robinson.1991，J.Cell Biol.113：743-756)。这些颗粒的细胞内动力学机制尚未完全阐明。本研究的目的是利用电透细胞研究 GTP 结合蛋白在含碱性磷酸酶颗粒的重组和胞吐作用中的参与。在生化测定中，完整的中性粒细胞在 AIF_4^- 和 N-formy1 肽刺激后显示细胞表面碱性磷酸酶活性上调。用百日咳毒素或肉毒杆菌毒素处理细胞可以抑制这种上调。在用 GTPgammaS 刺激的电透化细胞中，碱性磷酸酶活性也上调，但用 GDPbetaS 则不然。在细胞化学研究中，在未刺激的电透化中性粒细胞中，含有碱性磷酸酶的颗粒分散地分布在整个细胞质中。在用 GTPgammaS（而非 GDPbetaS）刺激后，这些颗粒融合成与质膜相关的细长管状结构。诺考达唑在 GTPgammaS 刺激后扰乱含碱性磷酸酶颗粒的重组。这项研究的结果表明，GTP 结合蛋白参与含碱性磷酸酶颗粒的重组和胞吐作用，这些颗粒与电透化的人中性粒细胞中的微管相关。