G protein-coupled APJ receptor signaling induces focal adhesion formation and cell motility.
G protein-coupled APJ receptor signaling induces focal adhesion formation and cell motility.
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DOI：
10.3892/ijmm.16.5.787
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发表时间：
2005-11
影响因子：
5.4
通讯作者：
Yasumi Hashimoto;J. Ishida;R. Yamamoto;K. Fujiwara;S. Asada;Y. Kasuya;N. Mochizuki;A. Fukamizu
中科院分区：
文献类型：
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作者：
Yasumi Hashimoto;J. Ishida;R. Yamamoto;K. Fujiwara;S. Asada;Y. Kasuya;N. Mochizuki;A. Fukamizu
APJ是一种G蛋白偶联受体，它有一种内源性配体，称为apelin。APJ和apelain在从胚胎到成年期的心血管系统中高度表达。已有研究表明，apelin可诱导表达APJ的细胞迁移，但受体信号转导的细节尚未确定。为了研究Apelin/APJ诱导细胞运动的信号转导分子机制，我们建立了稳定表达小鼠APJ(APJ/293T)的人胚胎肾293T细胞。APJ/293T细胞具有[(Glp65，Nle75，Tyr77)[125I]]-Apelin13结合活性(Kd=4.45 nM)。Apelin可诱导APJ/293T细胞Akt/PKB的磷酸化，但不能诱导完整的293T细胞(-/293T细胞)的Akt/PKB磷酸化。百日咳毒素(PTX)和PI3K抑制剂LY29004可显著抑制这种APJ依赖的Akt/PKB激活。此外，apelin可促进APJ/293T细胞中粘着斑激酶(FAK)的磷酸化，并通过F-肌动蛋白染色增加粘着斑形成。PTX和LY29004可显著抑制对apelin的上述反应。此外，我们使用划痕测试来检查迁移活动。Apelin可显著促进APJ/293T细胞的运动，这种作用可被PTX和LY29004所阻断。这些结果表明，Apelin/APJ信号与PTX敏感的G蛋白偶联，通过PI3K激活Akt/PKB和FAK蛋白。
APJ, a G protein-coupled receptor, has an endogenous ligand called apelin. APJ and apelain are highly expressed in the cardiovascular system from embryo to adulthood. It has been shown that apelin elicited the migration of APJ-expressing cells, but details of the receptor signaling have not been identified. To address the signal transduction molecular mechanisms of the apelin/APJ-induced cell motility, we established human embryonic kidney 293T cells stably expressing the mouse APJ (APJ/293T). APJ/293T cells exhibited a specific [(Glp65, Nle75, Tyr77) [125I]]-Apelin13 binding activity (Kd = 4.45 nM). Apelin induced Akt/PKB phosphorylation in APJ/293T cells, but not in the intact 293T cells (-/293T cells). This APJ-dependent activation of Akt/PKB was significantly inhibited by the pretreatment of pertussis toxin (PTx) and a PI3K inhibitor, LY29004. In addition, apelin enhanced focal adhesion kinase (FAK) phosphorylation and increased focal adhesion formation with staining for F-actin in APJ/293T cells. PTx and LY29004 significantly suppressed these responses to apelin. Moreover, we examined the migration activity by using a scratch-test. Apelin strongly accelerated the cell motility in APJ/293T cells, and this activity was abolished by PTx and LY29004. These results indicated that the apelin/APJ signaling coupled with the PTx-sensitive G-protein activates Akt/PKB and FAK proteins through PI3K.