Welsh J D, Swimmer C, Cocke T, Shenk T
Mol Cell Biol. 1986 Jun;6(6):2207-12. doi: 10.1128/mcb.6.6.2207-2212.1986.
Previous studies have demonstrated that mutations at amino acid position 128 of the simian virus 40 large T antigen can alter the subcellular localization of the antigen. A second domain in which mutations can alter localization of the nuclear antigen has been identified by mutations at amino acid positions 185, 186, and 199. Mutations in this region cause the polypeptide to accumulate in both the nucleus and cytoplasm of monkey cells. These T-antigen variants accumulate to near normal levels, but they don't bind to the simian virus 40 origin of DNA replication and are unable to mediate DNA replication. Furthermore, the altered tumor antigens can no longer transform secondary rat cells at normal efficiency, but they retain the ability to transform established mouse and rat cell lines.
先前的研究表明，猿猴病毒40大T抗原第128位氨基酸的突变可改变该抗原的亚细胞定位。通过第185、186和199位氨基酸的突变，已确定了另一个突变可改变核抗原定位的结构域。该区域的突变导致多肽在猴细胞核和细胞质中均有积累。这些T抗原变体积累至接近正常水平，但它们不与猿猴病毒40 DNA复制起点结合，也无法介导DNA复制。此外，改变后的肿瘤抗原不再能以正常效率转化二代大鼠细胞，但它们仍保留转化已建立的小鼠和大鼠细胞系的能力。
