Figure 7.

Spy1 can overcome a p27-induced G₁ arrest. (A) NIH3T3 wild-type cells were transfected with the indicated constructs and treated with BrdU for 2 h. The cells were then fixed and examined by immunofluorescence for BrdU incorporation by examination of GFP-positive cells. The graphed data indicate that there is an increase in DNA synthesis when p27 and Spy1 are coexpressed in comparison to p27 alone. (B) The lysates from the BrdU experiment were analyzed by 10% SDS-PAGE; immunoblotting with α-flag, α-GFP, and α-p27 sera show approximately equivalent levels of protein expression.