Aquaporin 9 phosphorylation mediates membrane localization and neutrophil polarization
Aquaporin 9 phosphorylation mediates membrane localization and neutrophil polarization
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DOI：
10.1189/jlb.0910540
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发表时间：
2011-11-01
影响因子：
5.5
通讯作者：
Magalhaes, Marco A. O.
中科院分区：
文献类型：
--
作者：
Karlsson, Thommie;Glogauer, Michael;Magalhaes, Marco A. O.
中性粒细胞在宿主抵抗入侵微生物的先天防御中起着至关重要的作用，它通过两种主要机制--向猎物移动和吞噬猎物。最近的研究指出水通道在细胞运动中的关键作用。在这里，我们集中在化学引诱剂诱导的极化和迁移的原代小鼠中性粒细胞和嗜中性粒细胞样HL 60细胞的AQP 9的作用。我们发现，AQP 9是磷酸化下游的fMLFR或PMA刺激在原代人中性粒细胞。AQP 9的动力学通过各种活细胞成像技术使用GFP标记的AQP 9构建体和其他荧光标记物进行评估。WT或磷酸化模拟S11 D AQP 9的表达改变了细胞体积调节，作为对高渗变化的反应，并增强了中性粒细胞的极化和趋化性。WT AQP 9和S11 D AQP 9在细胞膜上显示出非常动态的分布，而磷酸化缺陷的S11 A AQP 9未能定位于质膜。此外，我们发现Rac 1调节AQP 9向质膜的移位。我们的研究结果表明，AQP 9在中性粒细胞的体积调节和迁移中起着积极的作用。AQP 9在质膜上的展示依赖于AQP 9磷酸化，这似乎是通过Rac 1依赖性途径调节的。J. Leukoc. 90：963-973; 2011.
Neutrophils are of prime importance in the host innate defense against invading microorganisms by using two primary mechanisms-locomotion toward and phagocytosis of the prey. Recent research points to pivotal roles for water channels known as AQPs in cell motility. Here, we focused on the role of AQP9 in chemoattractant-induced polarization and migration of primary mouse neutrophils and neutrophil-like HL60 cells. We found that AQP9 is phosphorylated downstream of fMLFR or PMA stimulation in primary human neutrophils. The dynamics of AQP9 were assessed using GFP-tagged AQP9 constructs and other fluorescent markers through various live-cell imaging techniques. Expression of WT or the phosphomimic S11D AQP9 changed cell volume regulation as a response to hyperosmotic changes and enhanced neutrophil polarization and chemotaxis. WT AQP9 and S11D AQP9 displayed a very dynamic distribution at the cell membrane, whereas the phosphorylation-deficient S11A AQP9 failed to localize to the plasma membrane. Furthermore, we found that Rac1 regulated the translocation of AQP9 to the plasma membrane. Our results show that AQP9 plays an active role in neutrophil volume regulation and migration. The display of AQP9 at the plasma membrane depends on AQP9 phosphorylation, which appeared to be regulated through a Rac1-dependent pathway. J. Leukoc. Biol. 90: 963-973; 2011.