THE RECEPTOR FOR THE SUBGROUP-A AVIAN LEUKOSIS-SARCOMA VIRUSES BINDS TO SUBGROUP-A BUT NOT TO SUBGROUP-C ENVELOPE GLYCOPROTEIN
THE RECEPTOR FOR THE SUBGROUP-A AVIAN LEUKOSIS-SARCOMA VIRUSES BINDS TO SUBGROUP-A BUT NOT TO SUBGROUP-C ENVELOPE GLYCOPROTEIN
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DOI：
10.1128/jvi.68.9.5623-5628.1994
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发表时间：
1994-09-01
影响因子：
5.4
通讯作者：
WHITE, JM
中科院分区：
文献类型：
--
作者：
GILBERT, JM;BATES, P;WHITE, JM
最近通过基因转移克隆了推定的亚群A禽白血病-肉瘤病毒（ALSV）受体（Tva）（P. Bates，J.A.年轻的，和我。E. Varmus，Cell 74：1043-1051，1993; J. A. T. Young，P. Bates，and H. E. Varmus，J. Virol. 67：1811-1816，1993）。在用编码tva的cDNA转染后，细胞被赋予对亚群A ALSV感染的易感性。假设tva编码A亚群ALSV的特异性受体，预测Tva蛋白应结合A亚群，但不结合C亚群包膜糖蛋白。在这项研究中，我们通过使用几种生物化学测定来检验这一预测。我们建立了稳定的NIH 3 T3细胞系，表达Tva，亚组A包膜糖蛋白（Env-A）或亚组C包膜糖蛋白（Env-C），并将它们与这些分子的可溶性形式结合使用，以证明特异性结合。当含有Tva的细胞裂解物与Env-A或Env-C的裂解物混合时，在Tva和Env A之间形成免疫沉淀复合物，但在Tva和Env-C之间不形成免疫沉淀复合物。可溶性寡聚形式的Env-A，而不是Env-C，与表达Tva的细胞结合。反过来，分泌形式的Tva可以与表达Env-A的细胞结合，但不与表达Env-C的细胞结合。蔗糖密度梯度离心证明可溶性Env-A和分泌的Tva之间形成特异性和稳定的复合物。因此，通过三种测定，Tva似乎特异性结合Env-A，这与其作为亚群A ALSV的细胞表面受体和亚群特异性的主要决定因素的遗传证据一致。
The putative subgroup A avian leukosis-sarcoma virus (ALSV) receptor (Tva) was recently cloned by gene transfer (P. Bates, J. A. Young, and Il. E. Varmus, Cell 74:1043-1051, 1993; J. A. T. Young, P. Bates, and H. E. Varmus, J. Virol. 67:1811-1816, 1993). Susceptibility to infection by subgroup A ALSV is conferred on cells upon transfection with cDNAs encoding tva. The hypothesis that tva encodes a specific receptor for subgroup A ALSV predicts that the Tva protein should bind to subgroup A, but not to subgroup C, envelope glycoprotein. In this study, we examined this prediction by using several biochemical assays. We established stable NIH 3T3 cell lines expressing either Tva, the subgroup A envelope glycoprotein (Env-A), or the subgroup C envelope glycoprotein (Env-C) and used them in conjunction with soluble forms of these molecules to demonstrate specific binding. When cell lysates containing Tva were mixed with lysates of either Env-A or Env-C, an immunoprecipitable complex formed between Tva and Env A but not between Tva and Env-C. A soluble, oligomeric form of Env-A, not Env-C, binds to cells expressing Tva. Reciprocally, a secreted form of Tva can bind to cells expressing Env-A but not to cells expressing Env-C. A specific and stable complex formed between soluble Env-A and secreted Tva as demonstrated by sucrose density gradient centrifugation. Thus, by three kinds of assays, Tva appears to bind specifically to Env-A, which is consistent with genetic evidence that it serves as the cell surface receptor of subgroup A ALSV and the main determinant of subgroup specificity.