Different signal transduction properties of KDR and Flt1, two receptors for vascular endothelial growth factor.
Different signal transduction properties of KDR and Flt1, two receptors for vascular endothelial growth factor.
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DOI：
10.1016/s0021-9258(18)47116-5
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发表时间：
1994-10
期刊：
影响因子：
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通讯作者：
J. Waltenberger;L. Claesson-Welsh;Agneta Siegbahnll;M. Shibuya;Carl-Henrik HeldinS
中科院分区：
文献类型：
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作者：
J. Waltenberger;L. Claesson-Welsh;Agneta Siegbahnll;M. Shibuya;Carl-Henrik HeldinS
血管内皮生长因子（VEGF）是一种同源二聚体肽生长因子，与两种结构相关的酪氨酸激酶受体Flt 1和KDR结合。为了比较通过这两种受体的信号转导，人Flt 1和KDR蛋白在猪主动脉内皮细胞中稳定表达。使用125 I-VEGF的结合分析显示Flt 1的Kd值为16 pM，KDR的Kd值为760 pM。培养的人脐静脉内皮（HUVE）细胞被发现表达两个不同的人口的结合位点的亲和力相似的Flt 1和KDR，分别。表达KDR的细胞在VEGF刺激后表现出细胞形态、肌动蛋白重组和膜皱褶、趋化性和促有丝分裂性的显著变化，而表达Flt 1的细胞缺乏这种反应。KDR被发现在完整细胞中进行配体诱导的自磷酸化，并且Flt 1和KDR在体外响应于VEGF被磷酸化，然而，KDR比Flt 1更有效。Flt 1或KDR表达细胞的刺激既不影响磷脂酰肌醇3 '-激酶的受体相关活性，也不影响磷脂酶C-γ的酪氨酸磷酸化，并且GT3活化蛋白的磷酸化仅略微增加。Src家族的成员，如Fyn和Yes，在VEGF刺激表达Flt 1的细胞后显示出磷酸化水平增加，但在表达KDR的细胞中没有。表达KDR的猪主动脉内皮细胞中的最大反应在与HUVE细胞相比更高的VEGF浓度下获得，即在Flt 1存在下。这种差异可能是通过在HUVE细胞中KDR和Flt 1或其他分子之间形成异二聚体复合物来解释的。
Vascular endothelial growth factor (VEGF) is a homodimeric peptide growth factor which binds to two structurally related tyrosine kinase receptors denoted Flt1 and KDR. In order to compare the signal transduction via these two receptors, the human Flt1 and KDR proteins were stably expressed in porcine aortic endothelial cells. Binding analyses using 125I-VEGF revealed Kd values of 16 pM for Flt1 and 760 pM for KDR. Cultured human umbilical vein endothelial (HUVE) cells were found to express two distinct populations of binding sites with affinities similar to those for Flt1 and KDR, respectively. The KDR expressing cells showed striking changes in cell morphology, actin reorganization and membrane ruffling, chemotaxis and mitogenicity upon VEGF stimulation, whereas Flt1 expressing cells lacked such responses. KDR was found to undergo ligand-induced autophosphorylation in intact cells, and both Flt1 and KDR were phosphorylated in vitro in response to VEGF, however, KDR much more efficiently than Flt1. Neither the receptor-associated activity of phosphatidylinositol 3'-kinase nor tyrosine phosphorylation of phospholipase C-gamma were affected by stimulation of Flt1 or KDR expressing cells, and phosphorylation of GTPase activating protein was only slightly increased. Members of the Src family such as Fyn and Yes showed an increased level of phosphorylation upon VEGF stimulation of cells expressing Flt1 but not in cells expressing KDR. The maximal responses in KDR expressing porcine aortic endothelial cells were obtained at higher VEGF concentrations as compared to HUVE cells, i.e. in the presence of Flt1. This difference could possibly be explained by the formation of heterodimeric complexes between KDR and Flt1, or other molecules, in HUVE cells.