Binding of pigment epithelium-derived factor (PEDF) to retinoblastoma cells and cerebellar granule neurons - Evidence for a PEDF receptor
Binding of pigment epithelium-derived factor (PEDF) to retinoblastoma cells and cerebellar granule neurons - Evidence for a PEDF receptor
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DOI：
10.1074/jbc.274.44.31605
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发表时间：
1999-10-29
影响因子：
4.8
通讯作者：
Becerra, SP
中科院分区：
文献类型：
--
作者：
Alberdi, E;Aymerich, MS;Becerra, SP
色素上皮衍生因子（PEDF）；具有神经元分化和存活；对视网膜母细胞瘤和小脑颗粒（CG）细胞的活性。在这里，我们研究了PEDF受体在视网膜母细胞瘤Y-79和CG细胞上的存在。用I-125放射性标记的PEDF保持生物活性，并用于放射性配体结合分析。这种结合是饱和的，对两种细胞上的一类受体具有特异性，并且具有相似的亲和力（K-d = 1.7-3.6 nM, B-max = 10.5-2.7 × 10(5)个位点/Y-79细胞）；K-d = 3.2 nM, B-max = 1.1 × 10(3)个位点/CG细胞)。一种针对PEDF的多克隆抗血清，先前显示可阻断PEDF的神经营养活性，阻止I-125-PEDF结合。我们设计了两种来自先前显示赋予人类PEDF神经营养特性的区域的肽，合成肽34-mer（位置44-77）和44-mer（位置78-121）。只有44-mer肽竞争与Y-79细胞受体结合（EC50 = 5 nM）并表现出神经元分化活性。两种细胞类型的膜蛋白的PEDF亲和柱层析显示一个类似于80 kDa的PEDF结合蛋白。这些结果首次证明了PEDF结合蛋白具有PEDF受体的特征，并表明PEDF氨基酸位置78-121的区域可能参与配体与受体的相互作用。
Pigment epithelium-derived factor (PEDF);has neuronal differentiation and survival;activity on retinoblastoma and cerebellar granule (CG) cells. Here, we investigated the presence of PEDF receptors on retinoblastoma Y-79 and CG cells. PEDF radiolabeled with I-125 remained biologically active and was used for radioligand binding analysis. The binding was saturable and specific to a single class of receptors on both cells and with similar affinities (K-d = 1.7-3.6 nM, B-max = 10.5-2.7 x 10(5) sites/Y-79 cell; and K-d = 3.2 nM, B-max = 1.1 x 10(3) sites/CG cell). A polyclonal antiserum to PEDF, previously shown to block the PEDF neurotrophic activity, prevented the I-125-PEDF binding. We designed two peptides from a region previously shown to confer the neurotrophic property to human PEDF, synthetic peptides 34-mer (positions 44-77) and 44-mer (positions 78-121). Only peptide 44-mer competed for the binding to Y-79 cell receptors (EC50 = 5 nM) and exhibited neuronal differentiating activity. PEDF affinity column chromatography of membrane proteins from both cell types revealed a PEDF-binding protein of similar to 80 kDa. These results are the first demonstration of at PEDF-binding protein with characteristics of a PEDF receptor and suggest that the region comprising amino acid positions 78-121 of PEDF might be involved in ligand-receptor interactions.