Identification of anaplastic lymphoma kinase as a receptor for the growth factor pleiotrophin
Identification of anaplastic lymphoma kinase as a receptor for the growth factor pleiotrophin
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DOI：
10.1074/jbc.m010660200
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发表时间：
2001-05-18
影响因子：
4.8
通讯作者：
Wellstein, A
中科院分区：
文献类型：
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作者：
Stoica, GE;Kuo, A;Wellstein, A
多效生长因子（PTN）是一种分泌的生长因子，可诱导神经突生长，并对成纤维细胞、上皮细胞和内皮细胞有促有丝分裂作用。在肿瘤生长过程中，PTN可作为血管生成因子，驱动肿瘤的侵袭和转移。为了鉴定PTN的受体，我们构建了针对固定化PTN蛋白的噬菌体展示人cDNA文库作为诱饵。由此，我们分离了与孤儿受体酪氨酸激酶间变性淋巴瘤激酶（ALK）的细胞外结构域（ECD）中的氨基酸序列延伸同源的噬菌体插入物。与PTN平行，ALK在神经系统的围产期发育期间高度表达并且在成人中下调。我们在无细胞试验以及完整细胞中的放射性配体受体结合研究中显示，PTN与ALK ECD结合的表观Kd为32 +/- 9 pM。过量PTN、ALK ECD以及抗PTN和抗ECD抗体可抑制该受体结合。向ALK表达细胞中加入PTN可诱导ALK和下游效应分子IRS-1、She、磷脂酶C-γ和磷脂酰肌醇3-激酶的磷酸化。此外，PTN对培养物中不同细胞系的生长刺激作用与ALK mRNA的内源性表达一致，并且PTN的作用通过ALK过表达增强。由此我们得出结论，ALK是一种转导PTN介导的信号的受体，并提出PTN-ALK轴在发育和疾病过程中发挥重要作用。
Pleiotrophin (PTN) is a secreted growth factor that induces neurite outgrowth and is mitogenic for fibroblasts, epithelial, and endothelial cells. During tumor growth PTN can serve as an angiogenic factor and drive tumor invasion and metastasis, To identify a receptor for PTN, we penned a phage display human cDNA library against immobilized PTN protein as a bait. From this we isolated a phage insert that was homologous to an amino acid sequence stretch in the extracellular domain (ECD) of the orphan receptor tyrosine kinase anaplastic lymphoma kinase (ALK), In parallel with PTN, ALK is highly expressed during perinatal development of the nervous system and down-modulated in the adult. Here we show in cell-free assays as well as in radioligand receptor binding studies in intact cells that PTN binds to the ALK ECD with an apparent K-d of 32 +/- 9 pM, This receptor binding is inhibited by an excess of PTN, by the ALK ECD, and by anti-PTN and anti-ECD antibodies. PTN added to ALK-expressing cells induces phosphorylation of both ALK and of the downstream effector molecules IRS-1, She, phospholipase C-gamma, and phosphatidylinositol 3-kinase, Furthermore, the growth stimulatory effect of PTN on different cell lines in culture coincides with the endogenous expression of ALK mRNA, and the effect of PTN is enhanced by ALK overexpression. From this we conclude that ALK is a receptor that transduces PTN-mediated signals and propose that the PTN-ALK axis can play a significant role during development and during disease processes.