Montenarh M, Kohler M, Aggeler G, Henning R
EMBO J. 1985 Nov;4(11):2941-7. doi: 10.1002/j.1460-2075.1985.tb04027.x.
We have investigated the functional roles of two structural subsets of simian virus 40 (SV40) large T antigen, namely homo-oligomers and complexes with the host cellular p53 protein, for the transformed phenotype. We examined T antigen produced in cells transformed by temperature-sensitive SV40 large T mutants: heat-sensitive or unrestricted SV40 tsA58-transformed rat cells and unrestricted tsA1499 transformants. In both unrestricted cell lines, T antigen was temperature-sensitive only for the formation of fast sedimenting homo-oligomers. Corresponding to our recent observations obtained with tsA1499-infected monkey cells, in tsA1499 transformants large T was competent to form stable T-p53 complexes independently of the temperature. However, T antigen coded for by tsA58, which is heat-sensitive for binding to p53, occurred in stable complexes with this protein in unrestricted tsA58 transformants under all conditions. Furthermore, in both unrestricted transformants T-p53 complexes arise in the absence of homo-oligomers of T antigen. In conclusion, T antigen homo-oligomers are not involved in cell transformation, whereas T-p53 complexes may be involved in the maintenance of this phenotype.
我们研究了猴病毒40（SV40）大T抗原的两个结构亚群，即同型寡聚体和与宿主细胞p53蛋白的复合物，在转化表型中的功能作用。我们检测了由温度敏感型SV40大T突变体转化的细胞中产生的T抗原：热敏感型或不受温度限制的SV40 tsA58转化的大鼠细胞以及不受温度限制的tsA1499转化体。在这两种不受温度限制的细胞系中，T抗原仅在快速沉降的同型寡聚体形成方面对温度敏感。与我们最近用tsA1499感染的猴细胞所获得的观察结果一致，在tsA1499转化体中，大T能够独立于温度形成稳定的T-p53复合物。然而，tsA58编码的T抗原对与p53的结合是热敏感的，在不受温度限制的tsA58转化体中，在所有条件下该蛋白都与p53形成稳定的复合物。此外，在这两种不受温度限制的转化体中，T-p53复合物在没有T抗原同型寡聚体的情况下出现。总之，T抗原同型寡聚体不参与细胞转化，而T-p53复合物可能参与维持这种表型。
