PURIFICATION AND CHARACTERIZATION OF HUMAN PAPILLOMAVIRUS TYPE-16 E7 PROTEIN WITH PREFERENTIAL BINDING-CAPACITY TO THE UNDERPHOSPHORYLATED FORM OF RETINOBLASTOMA GENE-PRODUCT
PURIFICATION AND CHARACTERIZATION OF HUMAN PAPILLOMAVIRUS TYPE-16 E7 PROTEIN WITH PREFERENTIAL BINDING-CAPACITY TO THE UNDERPHOSPHORYLATED FORM OF RETINOBLASTOMA GENE-PRODUCT
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DOI：
10.1128/jvi.65.9.4966-4972.1991
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发表时间：
1991-09-01
影响因子：
5.4
通讯作者：
TERADA, M
中科院分区：
文献类型：
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作者：
IMAI, Y;MATSUSHIMA, Y;TERADA, M
人乳头瘤病毒16型E7被认为是一种主要的病毒癌蛋白，在宫颈癌中发挥重要作用。E7蛋白显示与视网膜母细胞瘤基因（RB）的蛋白产物结合，而猿猴病毒40大T和腺病毒E1 A也显示具有与RB蛋白的结合活性。RB蛋白是一种细胞周期调节因子，在S、G2和M期高度磷酸化，而在G 0和G1期磷酸化不足。最近，大T被证明优先结合到磷酸化不足的RB蛋白，这被认为是一个积极的形式限制细胞增殖。然而，E7是否能与磷酸化RB蛋白结合尚不清楚。我们成功地纯化了大量的未融合的人乳头瘤病毒16型E7蛋白在大肠杆菌中表达，通过使用T7启动子-T7 RNA聚合酶系统。纯化的E7蛋白被证明优先结合到磷酸化不足的RB蛋白。
Human papillomavirus type 16 E7 is considered to be a major viral oncoprotein playing an important role(s) in cervical cancers. E7 protein was shown to bind to the protein product of the retinoblastoma gene (RB), while simian virus 40 large T and adenovirus E1A were also shown to possess binding activity to RB protein. The RB protein is a cell cycle regulator that is highly phosphorylated specifically in S, G2, and M, whereas it is underphosphorylated in G0 and G1. Recently, large T was demonstrated to bind preferentially to the underphosphorylated RB protein, which is considered to be an active form restricting cell proliferation. However, it is not known whether E7 can bind to phosphorylated RB protein. We successfully purified large quantities of unfused human papillomavirus type 16 E7 protein expressed in Escherichia coli by using a T7 promoter-T7 RNA polymerase system. The purified E7 protein was demonstrated to bind preferentially to the underphosphorylated RB protein.