FEATURES

FAMILY

DESCRIPTION

Also known as RB_HUMAN, RB1. Tumor suppressor that is a key regulator of the G1/S transition of the cell cycle (PubMed:10499802). The hypophosphorylated form binds transcription regulators of the E2F family, preventing transcription of E2F-responsive genes (PubMed:10499802). Both physically blocks E2Fs transactivating domain and recruits chromatin-modifying enzymes that actively repress transcription (PubMed:10499802). Cyclin and CDK-dependent phosphorylation of RB1 induces its dissociation from E2Fs, thereby activating transcription of E2F responsive genes and triggering entry into S phase (PubMed:10499802). RB1 also promotes the G0-G1 transition upon phosphorylation and activation by CDK3/cyclin-C (PubMed:15084261). Directly involved in heterochromatin formation by maintaining overall chromatin structure and, in particular, that of constitutive heterochromatin by stabilizing histone methylation. Recruits and targets histone methyltransferases SUV39H1, KMT5B and KMT5C, leading to epigenetic transcriptional repression. Controls histone H4 'Lys-20' trimethylation. Inhibits the intrinsic kinase activity of TAF1. Mediates transcriptional repression by SMARCA4/BRG1 by recruiting a histone deacetylase (HDAC) complex to the c-FOS promoter. In resting neurons, transcription of the c-FOS promoter is inhibited by BRG1-dependent recruitment of a phospho-RB1-HDAC1 repressor complex. Upon calcium influx, RB1 is dephosphorylated by calcineurin, which leads to release of the repressor complex (By similarity)., (Microbial infection) In case of viral infections, interactions with SV40 large T antigen, HPV E7 protein or adenovirus E1A protein induce the disassembly of RB1-E2F1 complex thereby disrupting RB1's activity. Interacts with ATAD5. Interacts with PRMT2, CDK1 and CDK2 (By similarity). The hypophosphorylated form interacts with and sequesters the E2F1 transcription factor (PubMed:8336704, PubMed:20940255). Interacts with heterodimeric E2F/DP transcription factor complexes containing TFDP1 and either E2F1, E2F3, E2F4 or E2F5, or TFDP2 and E2F4. The unphosphorylated form interacts with EID1, ARID3B, KDM5A, SUV39H1, MJD2A/JHDM3A and THOC1. Interacts with the N-terminal domain of TAF1. Interacts with SNW1, AATF, DNMT1, LIN9, LMNA, KMT5B, KMT5C, PELP1, UHRF2 and TMPO-alpha. May interact with NDC80. Interacts with GRIP1 and UBR4. Interacts with ARID4A and KDM5B. Interacts with E4F1 and LIMD1. Interacts with SMARCA4/BRG1 AND HDAC1 (By similarity). Interacts with PSMA3 and USP4. Interacts (when methylated at Lys-860) with L3MBTL1. Interacts with CHEK2; phosphorylates RB1. Interacts with CEBPA (PubMed:15107404). P-TEFB complex interacts with RB1; promotes phosphorylation of RB1 (PubMed:12037672). Interacts with RBBP9; the interaction disrupts RB1 binding to E2F1 (By similarity). Interacts with KAT2B/PCAF and EP300/P300 (By similarity). Interacts with PAX5 (PubMed:10197586).

EXTERNAL LINKS

RB1

Retinoblastoma-associated protein

RB1

Molecular Synopsis