Figure 6.

Phosphorylation requirements for Skp2 binding and destabilization of p130. (A) Thymidine-arrested U2OS cells were infected with either empty, Skp2-expressing, Skp2(ΔFbox)-expressing, or p16^INK4-expressing recombinant adenoviruses, maintained under thymidine arrest, and harvested 18 h after infection for Western blot analysis. (B) Thymidine-arrested U2OS cells expressing the indicated HA-tagged recombinant alleles of p130 were infected with either empty or Skp2-expressing recombinant adenoviruses, maintained under thymidine arrest, and harvested 18 h after infection for Western blot analysis. (C) Pulse-chase analysis of p130 decay in thymidine-arrested U2OS cells expressing either β-galactosidase, HA-tagged wt p130, or HA-tagged S672A p130 after infection with either empty or Skp2-expressing recombinant adenoviruses.