Simian virus 40 T antigen can transcriptionally activate and mediate viral DNA replication in cells which lack the retinoblastoma susceptibility gene product

Abstract

Simian virus 40 T antigen is a multifunctional protein which has recently been shown to form a complex with the retinoblastoma susceptibility gene product (Rb protein) (J.A. DeCaprio, J.W. Ludlow, J. Figge, J.-Y. Shaw, C.-M. Huang, W.-H. Lee, E. Marsilio, E. Paucha, and D.M. Livingston, Cell 54:275-283, 1988; P. Whyte, K.J. Buchkovich, J.M. Horowitz, S.H. Friend, M. Raybuck, R.A. Weinberg, and E. Harlow, Nature (London) 334:124-129, 1988). This interaction may facilitate some of the functions of T antigen. The ability of simian virus 40 T antigen to mediate transcriptional activation and viral DNA replication was tested in human osteosarcoma cell lines U-2OS and Saos-2, which are Rb positive and Rb negative, respectively. Both functions of T antigen were efficient in both cell lines. Hence, these functions can occur in the absence of Rb protein.