T-antigen binding sites in mammalian genome

[Andrew K. Groves]

In article <2tr1gh$6u8 at ysics.physics.sunysb.edu>,
mhollowa at epo.som.sunysb.edu wrote:

> Can anyone tell me if any good work has been done to explain 
> the function of SV-40 large T-antigen binding sites in the 
> genome.  Are they just randomly distributed or does the SV40 
> protein take advantage of a cellular protein's binding site?  
> The organism doesn't maintain the site so that SV40 can 
> transform the cells.  It should have some cellular function, no?
> 

SV40 large T does not need to bind to DNA to immortalise cells. The U19
strain of the tsA58 temperature sensitive SV40 T antigen mutant cannot bind
DNA, but is more potent at immortalising (as, for example, measured by
colony assays) than the original tsA58 mutant. 

I believe it has been shown that the SV40 T antigen can form complexes with
both p53 and with the RB gene product. It is probably these activities that
cause the large T antigen to immortalise cells.

-- 
Andy Groves
Division of Biology, 216-76
California Institute of Technology