Chemotaxis in a lymphocyte cell line transfected with C-C chemokine receptor 2B:: Evidence that directed migration is mediated by βγ dimers released by activation of Gαi-coupled receptors
Chemotaxis in a lymphocyte cell line transfected with C-C chemokine receptor 2B:: Evidence that directed migration is mediated by βγ dimers released by activation of Gαi-coupled receptors
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DOI：
10.1073/pnas.94.26.14495
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发表时间：
1997-12-23
影响因子：
11.1
通讯作者：
Charo, IF
中科院分区：
文献类型：
--
作者：
Arai, H;Tsou, CL;Charo, IF
趋化性是由7个跨膜结构域G蛋白偶联受体的激活介导的，但导致趋化性的信号转导途径尚不清楚。为了鉴定指示细胞定向迁移的G蛋白，我们稳定地转染了一个淋巴细胞系（300-19），其中G蛋白偶联受体仅偶联G(α q) （m3毒毒碱受体），G(α i) （kappa-阿片受体）和G(α s) （β肾上腺素能受体），以及人凝血酶受体（PAR-1）和C-C趋化因子受体2B。表达与G（α i）偶联但不与G（α q）或G（α s）偶联的受体的细胞，随着适当激动剂的浓度梯度而迁移。G（α）转导蛋白与游离G（β - γ）二聚体结合并失活，其过表达完全阻断趋化性，尽管对细胞内钙动员或其他细胞信号传导措施几乎没有影响。G（β - γ）二聚体作为趋化信号通路的关键中间体的鉴定进一步证明了哺乳动物细胞的趋化性与酵母的极化反应具有重要的相似性。我们得出结论，趋化性依赖于G（α i）的激活和G（β - γ）二聚体的释放，并且传统上与趋化性无关的G（α i）偶联受体在造血细胞中表达时可以介导定向迁移。
Chemotaxis is mediated by activation of seven-transmembrane domain, G protein-coupled receptors, but the signal transduction pathways leading to chemotaxis are poorly understood. To identify G proteins that signal the directed migration of cells, we stably transfected a lymphocyte cell line (300-19) with G protein-coupled receptors that couple exclusively to G(alpha q) (the m3 muscarinic receptor), G(alpha i) (the kappa-opioid receptor), and G(alpha s) (the beta-adrenergic receptor), as well as the human thrombin receptor (PAR-1) and the C-C chemokine receptor 2B. Cells expressing receptors that coupled to G(alpha i), but not to G(alpha q) or G(alpha s), migrated in response to a concentration gradient of the appropriate agonist. Overexpression of G(alpha) transducin, which binds to and inactivates free G(beta gamma) dimers, completely blocked chemotaxis although having little or no effect on intracellular calcium mobilization or other measures of cell signaling. The identification of G(beta gamma) dimers as a crucial intermediate in the chemotaxis signaling pathway provides further evidence that chemotaxis of mammalian cells has important similarities to polarized responses in yeast. We conclude that chemotaxis is dependent on activation of G(alpha i) and the release of G(beta gamma) dimers, and that G(alpha i)-coupled receptors not traditionally associated with chemotaxis can mediate directed migration when they are expressed in hematopoietic cells.