Rong L, Bates P
Department of Microbiology, School of Medicine, University of Pennsylvania, Philadelphia 19104, USA.
J Virol. 1995 Aug;69(8):4847-53. doi: 10.1128/JVI.69.8.4847-4853.1995.
The genes encoding the receptor for subgroup A Rous sarcoma viruses (tva) were recently cloned from both chicken and quail cells (P. Bates, J. A. T. Young, and H. E. Varmus, Cell 74:1043-1051, 1993; J. A. T. Young, P. Bates, and H. E. Varmus, J. Virol. 67:1811-1816, 1993). Previous work suggested that only the extracellular domain of Tva interacts with the virus (P. Bates, J. A. T. Young, and H. E. Varmus, Cell 74:1043-1051, 1993). Tva is a small membrane-associated protein containing in its extracellular domain a 40-amino-acid region which is closely related to the low-density lipoprotein receptor (LDLR) repeat motif. To determine the region of the Tva extracellular domain responsible for viral receptor function, we created chimeric proteins containing various regions of the Tva extracellular domain fused with a murine CD8 membrane anchor. Analysis of these proteins demonstrates that any chimera containing the Tva LDLR repeat motif can specifically bind the envelope protein of subgroup A avian sarcoma and leukosis viruses. Furthermore, NIH 3T3 cell lines expressing these chimeric proteins were efficiently infected by subgroup A avian sarcoma and leukosis virus vectors. Our results demonstrate that the 40-residue-long LDLR repeat motif of Tva is responsible for viral receptor function.
编码劳氏肉瘤病毒A亚群受体（tva）的基因最近已从鸡和鹌鹑细胞中克隆出来（P. 贝茨、J. A. T. 扬和H. E. 瓦尔默斯，《细胞》74:1043 - 1051，1993；J. A. T. 扬、P. 贝茨和H. E. 瓦尔默斯，《病毒学杂志》67:1811 - 1816，1993）。先前的研究表明，只有Tva的细胞外结构域与病毒相互作用（P. 贝茨、J. A. T. 扬和H. E. 瓦尔默斯，《细胞》74:1043 - 1051，1993）。Tva是一种小的膜相关蛋白，其细胞外结构域包含一个与低密度脂蛋白受体（LDLR）重复基序密切相关的40个氨基酸的区域。为了确定Tva细胞外结构域中负责病毒受体功能的区域，我们构建了嵌合蛋白，这些嵌合蛋白包含Tva细胞外结构域的各个区域与鼠CD8膜锚定序列融合。对这些蛋白的分析表明，任何包含Tva LDLR重复基序的嵌合体都能特异性结合A亚群禽肉瘤和白血病病毒的包膜蛋白。此外，表达这些嵌合蛋白的NIH 3T细胞系被A亚群禽肉瘤和白血病病毒载体有效感染。我们的结果表明，Tva的40个氨基酸长的LDLR重复基序负责病毒受体功能。
