Lectin-induced activation of plasma membrane NADPH oxidase in cholesterol-depleted human neutrophils
Lectin-induced activation of plasma membrane NADPH oxidase in cholesterol-depleted human neutrophils
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DOI：
10.1016/j.abb.2011.10.013
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发表时间：
2011-12-15
影响因子：
3.9
通讯作者：
Timoshenko, Alexander V.
中科院分区：
文献类型：
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作者：
Gorudko, Irina V.;Mukhortava, Ann V.;Timoshenko, Alexander V.
黄细胞色素10558的gp 91 phox亚基是吞噬细胞质膜NADPH氧化酶的催化核心。它的激活发生在脂筏内，需要四个亚基移位为黄细胞色素B（558）。gp 91 phox是NADPH氧化酶的唯一糖基化亚基，并且没有关于其聚糖的结构或功能的数据。然而，聚糖与凝集素结合，这可以刺激NADPH氧化酶活性。鉴于这一信息，我们假设凝集素gp 91 phox相互作用将促进组装的功能活性NADPH氧化酶的脂筏的情况下。为了测试这一点，我们使用了不同的碳水化合物结合特异性的凝集素，以检查脂质筏破坏剂甲基-β-环糊精（M β CD）处理的人中性粒细胞对H2 O2生成的影响。M β CD处理去除膜胆固醇，引起细胞形态的变化，抑制凝集素诱导的细胞聚集，并延迟凝集素诱导的NADPH氧化酶复合物的组装。更重要的是，M β CD治疗刺激或抑制H2 O2的生产在凝集素依赖性的方式。总之，这些结果表明选择性凝集素结合gp 91 phox，并提供证据的gp 91 phox聚糖的生化结构。此外，数据还表明，在脂筏的情况下，中性粒细胞NADPH氧化酶活性可以改变这些选择凝集素。(C)2011 Elsevier Inc. All rights reserved.
The gp91phox subunit of flavocytochrome 10558 is the catalytic core of the phagocyte plasma membrane NADPH oxidase. Its activation occurs within lipid rafts and requires translocation of four subunits to flavocytochrome b(558). gp91 phox is the only glycosylated subunit of NADPH oxidase and no data exist about the structure or function of its glycans. Glycans, however, bind to lectins and this can stimulate NADPH oxidase activity. Given this information, we hypothesized that lectin-gp91 phox interactions would facilitate the assembly of a functionally active NADPH oxidase in the absence of lipid rafts. To test this, we used lectins with different carbohydrate-binding specificity to examine the effects on H2O2 generation by human neutrophils treated with the lipid raft disrupting agent methyl-beta-cyclodextrin (M beta CD). M beta CD treatment removed membrane cholesterol, caused changes in cell morphology, inhibited lectin-induced cell aggregation, and delayed lectin-induced assembly of the NADPH oxidase complex. More importantly, M beta CD treatment either stimulated or inhibited H2O2 production in a lectin-dependent manner. Together, these results show selectivity in lectin binding to gp91phox, and provide evidence for the biochemical structures of the gp91phox glycans. Furthermore, the data also indicate that in the absence of lipid rafts, neutrophil NADPH oxidase activity can be altered by these select lectins. (C) 2011 Elsevier Inc. All rights reserved.