Blockage of chemotactic peptide-induced stimulation of neutrophils by wortmannin as a result of selective inhibition of phosphatidylinositol 3-kinase.
Blockage of chemotactic peptide-induced stimulation of neutrophils by wortmannin as a result of selective inhibition of phosphatidylinositol 3-kinase.
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DOI：
10.1016/s0021-9258(17)41900-4
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发表时间：
1994-02
期刊：
影响因子：
--
通讯作者：
T. Okada;L. Sakuma;Y. Fukui;O. Hazeki;M. Ui
中科院分区：
文献类型：
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作者：
T. Okada;L. Sakuma;Y. Fukui;O. Hazeki;M. Ui
渥曼青霉素，真菌代谢产物，抑制32磷标记的磷脂酰肌醇三磷酸，磷脂酰肌醇3-激酶（PI 3-激酶）的产物，选择性在甲酰肽刺激的32磷负载的豚鼠中性粒细胞。的抑制是相同的浓度依赖性（与一半的最大抑制约50 nM），因为观察到的同时抑制甲酰肽诱导的超氧阴离子的产生。Wortmannin抑制豚鼠中性粒细胞胞质组分中发现的所有三种PI 3-激酶活性，具有相似的剂量依赖性（5 nM时的半数最大效应）。渥曼青霉素对酶的免疫纯化制剂也有效。抑制是一个非竞争性类型的ATP和观察时，PI，PI单磷酸，或PI二磷酸作为底物一致。PI 4-激酶活性不受影响。因此，可以得出结论，渥曼青霉素取消了甲酰肽诱导的刺激中性粒细胞作为PI 3-激酶抑制的结果。PI 3-激酶在中性粒细胞中受体介导的信号传导中的重要作用，从而证明了使用渥曼青霉素将扩展到其他细胞信号传导系统。
Wortmannin, a fungal metabolite, inhibited 32P labeling of phosphatidylinositol trisphosphate, a product of phosphatidylinositol 3-kinase (PI 3-kinase), selectively in formyl peptide-stimulated 32P-loaded guinea pig neutrophils. The inhibition was of the same concentration dependence (with the half-maximal inhibition around 50 nM) as was observed for the simultaneous inhibition of formyl peptide-induced superoxide anion production. Wortmannin inhibited all three of the PI 3-kinase activities found in the cytosol fraction of guinea pig neutrophils, with a similar dose dependence (the half-maximal effects at 5 nM). Wortmannin was also effective on an immunologically purified preparation of the enzyme. The inhibition was of a noncompetitive type with regard to ATP and was observed consistently when PI, PI monophosphate, or PI bisphosphate was used as substrate. PI 4-kinase activity was not affected. It is concluded, therefore, that wortmannin abolished the formyl peptide-induced stimulation of neutrophils as a result of the inhibition of PI 3-kinase. An essential role of PI 3-kinase in receptor-mediated signaling in neutrophils thus evidenced with the use of wortmannin will be expanded to other cellular signaling systems.