Cyclin D:CDK4/6 mediated phosphorylation of p107 (RBL1) and dissociation of phosphorylated p107 (p-RBL1) from DP1:E2F4 complex Authored: Orlic-Milacic, Marija, 2011-06-14 EC Number: 2.7.11.22 In late G1, cyclin D dependent kinases CDK4 and CDK6 phosphorylate RBL1 (p107) on four serine and threonine residues (S964, S975, T369 and S640), leading to dissociation of phosphorylated RBL1 (p107) from E2F4 in complex with either DP-1 or DP-2. E2F4, which lacks nuclear localization signal, is then thought to translocate to the cytosol, allowing E2F promoter sites to become occupied by activating E2Fs (E2F1, E2F2, and E2F3), resulting in transcription of E2F targets needed for cell cycle progression. Pubmed11884610 Pubmed7797074 Pubmed9144196 Reactome Database ID Release 431226095 Reactome, http://www.reactome.org ReactomeREACT_111248 Reviewed: MacPherson, D, 2011-08-25 has a Stoichiometric coefficient of 4 E2F4:DP1/2 RBL1:E2F4:DP1/2