An amino-terminal fragment of SV40 T antigen induces cellular DNA synthesis in quiescent rat cells.

SV40 large T antigen can stimulate cellular DNA synthesis in quiescent cells. Here we report that an SV40 mutant, which expresses only the amino-terminal 147 amino acids of this protein and which does not make small t antigen, stimulates cellular DNA synthesis in quiescent rat cells at levels similar to those achieved with serum stimulation. Thus, the amino-terminal 147 amino acids of large T antigen define a domain of this protein that is sufficient for efficient stimulation of cellular DNA synthesis in the absence of small t antigen.