Figure 1

Transcriptional control of the cell cycle by pRB. In G1 pRB is bound to E2Fs and masks their ability to activate transcription. In turn, pRB can recruit a number of chromatin remodeling factors that can further inhibit the initiation of transcription. Mitogen signaling then activates cyclin/Cdk complexes that phosphorylate pRB in late G1 and early S-phase leading to the disassembly of this complex and the activation of transcription of genes needed for progression through S-phase.