Vascular endothelial growth factor receptor-1 and neuropilin-2 form complexes
Vascular endothelial growth factor receptor-1 and neuropilin-2 form complexes
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DOI：
10.1074/jbc.m006909200
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发表时间：
2001-06-01
影响因子：
4.8
通讯作者：
Neufeld, G
中科院分区：
文献类型：
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作者：
Gluzman-Poltorak, Z;Cohen, T;Neufeld, G
neuropilin-1 （Np-1）和neuropilin-2 （Np-2）基因的产物是3类信号蛋白家族因子的受体，参与引导生长轴突到达目标。在肝素样分子存在的情况下，这两种受体也作为血管内皮生长因子（VEGF）的肝素结合165个氨基酸异构体的受体（165）。这两种受体都不能与缺乏肝素结合结构域的血管内皮生长因子（VEGF(121)）的121个氨基酸异构体结合。有趣的是，当I-125-VEGF（121）与共表达VEGFR-1和Np-1或Np-2的猪主动脉内皮细胞结合并交联时，形成了大小与I-125-VEGF（121）神经匹林复合物相当的复合物。这些复合物似乎不代表I-125-VEGF的复合物，具有截断形式的VEGFR-1，可能是由于细胞中存在Np-1或Np-2而形成的，因为抗VEGFR-1抗体无法检测到这种截断形式。针对VEGFR-1的抗体与I-125-VEGF（121）共免疫沉淀了Np-2大小的交联复合物。VEGFR-1复合物来自同时表达VEGFR-1和Np-2的细胞，而不来自对照细胞，表明VEGFR-1和Np-2相互关联。为了进行互反实验，我们在猪主动脉内皮细胞中表达了一个Np-2受体，该受体在C端含有一个框架内的myc表位。令人惊讶的是，myc标记的Np-2受体失去了大部分VEGF（165）结合能力，但没有失去信号素- 3f的结合能力。然而，当Np-2myc与VEGFR-1共表达在细胞中时，它部分恢复了其与VEGF（165）的结合能力。针对myc表位的抗体共同免疫沉淀I-125-VEGF（165）。Np-2myc和I-125-VEGF(165) VEGFR-1复合物来自共表达VEGFR-1和Np-2myc的细胞，再次表明VEGFR-1与Np-2相关。因此，我们的实验表明Np-2，也可能是Np-1，与VEGFR-1相关，这些复合物可能是细胞膜相关信号复合物的一部分。
The products of the neuropilin-1 (Np-1) and neuropilin-2 (Np-2) genes are receptors for factors belonging to the class 3 semaphorin family and participate in the guidance of growing axons to their targets. In the presence of heparin-like molecules, both receptors also function as receptors for the heparin-binding 165-amino acid isoform of vascular endothelial growth factor (VEGF(165)). Both receptors are unable to bind to the 121-amino acid isoform of vascular endothelial growth factor (VEGF(121)), which lacks a heparin-binding domain. Interestingly, complexes corresponding in size to I-125-VEGF(121) neuropilin complexes are formed when I-125-VEGF(121) is bound and cross-linked to porcine aortic endothelial cells co-expressing VEGFR-1 and either Np-1 or Np-2. These complexes do not seem to represent complexes of I-125-VEGF With a truncated form of VEGFR-1, presumably formed as a result of the presence of Np-1 or Np-2 in the cells, because such truncated forms could not be detected with anti-VEGFR-1 antibodies. Antibodies directed against VEGFR-1 co-immunoprecipitated the I-125-VEGF(121) Np-2 sized cross-linked complex along with I-125-VEGF(121). VEGFR-1 complexes from cells expressing both VEGFR-1 and Np-2 but not from control cells, indicating that VEGFR-1 and Np-2 associate with each other. To perform the reciprocal experiment we have expressed in porcine aortic endothelial cells a Np-2 receptor containing an in-frame myc epitope at the C terminus. Surprisingly, the myc-tagged Np-2 receptor lost most of its VEGF(165) binding capacity but not its semaphorin-3F binding ability. Nevertheless, when Np-2myc was co-expressed in cells with VEGFR-1, it partially regained its VEGF(165) binding ability. Antibodies directed against the myc epitope co-immunoprecipitated I-125-VEGF(165). Np-2myc and I-125-VEGF(165) VEGFR-1 complexes from cells co-expressing VEGFR-1 and Np-2myc, indicating again that VEGFR-1 associates with Np-2, Our experiments therefore indicate that Np-2, and possibly also Np-1, associate with VEGFR-1 and that such complexes may be part of a cell membrane-associated signaling complex.