text: During the M-to-G1 transition, pRb is then progressively dephosphorylated by PP1, returning to its growth-suppressive hypophosphorylated state.
  pRb family proteins are components of the DREAM complex composed of DP, E2F4/5, RB-like (p130/p107) And MuvB (Lin9:Lin37:Lin52:RbAbP4:Lin54). The DREAM complex is assembled in Go/G1 and maintains quiescence by assembling at the promoters of > 800 cell-cycle genes and mediating transcriptional repression. Assembly of DREAM requires DYRK1A (Ser/Thr kinase) dependant phosphorylation of the MuvB core component, Lin52 at Serine28. This mechanism is crucial for recruitment of p130/p107 to the MuvB core and thus DREAM assembly.