Altered DNA binding and replication activities of JC virus T-antigen mutants.
Altered DNA binding and replication activities of JC virus T-antigen mutants.
复制标题
JC 病毒 T 抗原突变体的 DNA 结合和复制活性发生改变。
DOI：
10.1016/0042-6822(91)90136-y
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发表时间：
1991
期刊：
影响因子：
3.7
通讯作者：
Frisque,RJ
中科院分区：
文献类型：
--
作者：
Tavis,JE;Frisque,RJ
在JC病毒（JCV）T抗原中与SV 40 T抗原DNA结合结构域（SV 40氨基酸131至220）对应的区域内引入了10个突变;其中9个突变增加了SV 40 T抗原DNA结合关键序列中两种蛋白质之间的同源性。所有突变型JCV T抗原均与JCV和SV 40 DNA复制起点结合。相对于野生型JCV T抗原的结合效率，JCV结合位点的结合效率为83 - 301%，SV 40结合位点的结合效率为44 - 240%。九个突变蛋白促进病毒DNA在原代人胎儿神经胶质细胞（PHFG）和CV-1细胞中的复制。在PHFG细胞中，相对于野生型T抗原，DNA复制的促进范围为26%至220%;在CV-1细胞中，其范围为14%至522%。将五种突变蛋白的编码序列转移到杂交病毒M1（SV 40）中[M1（SV 40）含有来自JCV的编码序列和来自SV 40的调控序列]。在CV-1细胞中，野生型T抗原促进这些杂交病毒中SV 40起点的弱复制（从JCV起点的2%）;由突变蛋白驱动的复制范围为由野生型蛋白诱导的复制的110至412%。突变T抗原的有效特异性DNA结合不是突变蛋白促进DNA复制能力的可靠指标。
Ten mutations were introduced into the JC virus (JCV) T antigen within a region corresponding to the SV40 T-antigen DNA binding domain (SV40 amino acids 131 to 220); nine of these increased homology between the two proteins in sequences critical for SV40 T antigen DNA binding. All mutant JCV T antigens bound to JCV and SV40 origins of DNA replication. Binding efficiency relative to that of wild-type JCV T antigen ranged from 83 to 301 % for the JCV binding sites and from 44 to 240% for the SV40 binding sites. Nine mutant proteins promoted viral DNA replication in primary human fetal glial (PHFG) and CV-1 cells. In PHFG cells, promotion of DNA replication ranged from 26 to 220% relative to that of wild-type T antigen; in CV-1 cells it ranged from 14 to 522%. Coding sequences for five mutant proteins were transferred into the hybrid virus M1(SV40) [M1(SV40) contains coding sequences from JCV and regulatory sequences from SV40]. Wild-type T antigen promoted replication weakly from the SV40 origin in these hybrid viruses in CV-1 cells (2% that from the JCV origin); replication driven by the mutant proteins ranged from 110 to 412% of that induced by the wild-type protein. Efficient specific DNA binding by a mutant T antigen was not a reliable indicator of that mutant protein's ability to promote DNA replication.