Christensen J B, Imperiale M J
Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor 48109-0620, USA.
J Virol. 1995 Jun;69(6):3945-8. doi: 10.1128/JVI.69.6.3945-3948.1995.
Simian virus 40 large T antigen interacts with three cellular proteins, pRb, p107, and p130, through a common binding site on the T antigen protein called the E1A conserved region 2-like (CR2-like) domain. Mutations in this domain inactivate the transforming activity of large T antigen. Since these mutations have been demonstrated to abolish binding to pRb and p107, and presumably therefore affect binding to p130, assessment of the relative roles of these three proteins in transformation of rodent fibroblasts by T antigen has been difficult. We have examined the role of T antigen-pRb interactions in transformation. We have introduced a mutant T antigen, which is unable to bind any of these three proteins, into primary mouse fibroblasts derived from the embryos of mice in which the Rb gene encoding the retinoblastoma protein had been disrupted. This mutant is unable to transform the Rb-negative fibroblasts, indicating that inactivation of pRb is not the sole function of the CR2-like domain in the induction of transformation of mouse fibroblasts by simian virus 40.
猴病毒40大T抗原通过T抗原蛋白上一个名为E1A保守区域2样（CR2样）结构域的共同结合位点与三种细胞蛋白pRb、p107和p130相互作用。该结构域中的突变会使大T抗原的转化活性失活。由于这些突变已被证明会消除与pRb和p107的结合，因此推测也会影响与p130的结合，所以评估这三种蛋白在T抗原转化啮齿动物成纤维细胞中的相对作用一直很困难。我们研究了T抗原与pRb相互作用在转化中的作用。我们将一种无法与这三种蛋白中的任何一种结合的突变型T抗原导入源自编码视网膜母细胞瘤蛋白的Rb基因已被破坏的小鼠胚胎的原代小鼠成纤维细胞中。这种突变体无法转化Rb阴性成纤维细胞，这表明pRb的失活不是猴病毒40诱导小鼠成纤维细胞转化过程中CR2样结构域的唯一功能。
