Identification of PECAM-1 association with sphingosine kinase 1 and its regulation by agonist-induced phosphorylation
Identification of PECAM-1 association with sphingosine kinase 1 and its regulation by agonist-induced phosphorylation
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DOI：
10.1016/j.bbalip.2003.11.006
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发表时间：
2004-02-27
影响因子：
4.8
通讯作者：
Igarashi, Y
中科院分区：
文献类型：
--
作者：
Fukuda, Y;Aoyama, Y;Igarashi, Y
1-磷酸鞘氨醇（S1 P）是由鞘氨醇通过鞘氨醇激酶（SPHK）产生的生物活性脂质介质。S1 P作为一种信号分子在细胞外和细胞内发挥作用，尽管其细胞内靶点仍不明确。细胞内S1 P水平受到SPHK调节、S1 P降解和S1 P去磷酸化的严格调控。因此，阐明SPHK活性的调节机制可能有助于我们了解S1 P产生的时间和地点。在这项研究中，我们进行了酵母双杂交筛选，以寻找SPHK 1a结合分子，可能参与调节激酶的定位或活性。血小板内皮细胞粘附分子-1（PECAM-1）被鉴定为可能与SPHK 1a相关的蛋白质。使用过表达PECAM-1和SPHK 1a的HEK 293细胞通过共免疫沉淀分析证实了它们的关联。此外，激酶活性似乎在稳定的PECAM-1表达细胞中降低。PECAM-1在血管细胞的细胞表面上表达，并且已知几种刺激物诱导其酪氨酸残基的磷酸化。我们发现这种磷酸化减弱了它与SPHK 1a的结合。SPHK与PECAM-1的这种结合/解离，受膜蛋白磷酸化状态的调节，可能参与某些细胞类型中局部激酶活性的控制。(C)2004 Elsevier B. V.保留所有权利。
Sphingosine 1-phosphate (S1P) is a bioactive lipid mediator generated from sphingosine by sphingosine kinase (SPHK). S1P acts both extracellularly and intracellularly as a signaling molecule, although its intracellular targets are still undefined. Intracellular level of S1P is under strict regulatory control of SPHK regulation, S1P degradation, and S1P dephosphorylation. Therefore, clarifying the mechanisms regulating SPHK activity may help us understand when and where S1P is generated. In this study, we performed yeast two-hybrid screening to search for SPHK1a-binding molecules that may be involved in the regulation of the kinase localization or activity. Platelet endothelial cell adhesion molecule-1 (PECAM-1) was identified as a protein potentially associating with SPHK1a. Their association was confirmed by coimmunoprecipitation analysis using HEK293 cells overexpressing PECAM-1 and SPHK1a. Moreover, the kinase activity appeared to be reduced in stable PECAM-1-expressing cells. PECAM-1 is expressed on the cell surface of vascular cells, and several stimuli are known to induce phosphorylation of its tyrosine residues. We found that such phosphorylation attenuated its association with SPHK1a. This association/dissociation of SPHK with PECAM-1, regulated by the phosphorylated state of the membrane protein, may be involved in the control of localized kinase activity in certain cell types. (C) 2004 Elsevier B.V. All rights reserved.