Rb Key regulator of entry into cell division that acts as a tumor suppressor. Promotes G0-G1 transition when phosphorylated by CDK3/cyclin-C. Acts as a transcription repressor of E2F1 target genes. The underphosphorylated, active form of RB1 interacts with E2F1 and represses its transcription activity, leading to cell cycle arrest. 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. (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. Belongs to the retinoblastoma protein (RB) family. Expressed in the retina. Note: This description may include information from UniProtKB.
Protein type: Nuclear receptor co-regulator; Oncoprotein; Transcription, coactivator/corepressor; Tumor suppressor
Chromosomal Location of rat Ortholog: 15q11
Cellular Component:  chromatin; cyclin/CDK positive transcription elongation factor complex; nucleoplasm; nucleus; PML body; Rb-E2F complex; spindle; transcription factor complex
Molecular Function:  disordered domain specific binding; enzyme binding; identical protein binding; importin-alpha family protein binding; kinase binding; phosphoprotein binding; protein binding; proximal promoter sequence-specific DNA binding; RNA polymerase II activating transcription factor binding; RNA polymerase II regulatory region DNA binding; transcription factor binding; ubiquitin protein ligase binding
Biological Process:  aortic valve morphogenesis; apoptotic process; cell cycle arrest; cell differentiation; cell division; cell morphogenesis involved in neuron differentiation; cellular response to xenobiotic stimulus; chromatin organization; digestive tract development; enucleate erythrocyte differentiation; G1/S transition of mitotic cell cycle; glial cell apoptotic process; hepatocyte apoptotic process; maintenance of mitotic sister chromatid cohesion; myoblast differentiation; negative regulation of apoptotic signaling pathway; negative regulation of cell cycle; negative regulation of cell proliferation; negative regulation of cold-induced thermogenesis; negative regulation of epithelial cell proliferation; negative regulation of G1/S transition of mitotic cell cycle; negative regulation of gene expression; negative regulation of hepatocyte apoptotic process; negative regulation of inflammatory response; negative regulation of mitotic cell cycle; negative regulation of myofibroblast differentiation; negative regulation of protein kinase activity; negative regulation of protein serine/threonine kinase activity; negative regulation of smoothened signaling pathway; negative regulation of tau-protein kinase activity; negative regulation of transcription by RNA polymerase II; negative regulation of transcription involved in G1/S transition of mitotic cell cycle; negative regulation of transcription, DNA-templated; neuron apoptotic process; neuron differentiation; neuron maturation; neuron projection development; positive regulation of collagen fibril organization; positive regulation of extracellular matrix organization; positive regulation of macrophage differentiation; positive regulation of mitotic metaphase/anaphase transition; positive regulation of transcription by RNA polymerase II; positive regulation of transcription regulatory region DNA binding; protein localization to chromosome, centromeric region; Ras protein signal transduction; regulation of cell cycle; regulation of cell growth; regulation of cohesin loading; regulation of lipid kinase activity; regulation of mitotic cell cycle; regulation of transcription by RNA polymerase II; sister chromatid biorientation; skeletal muscle cell differentiation; spermatogenesis; striated muscle cell differentiation; tissue homeostasis
Reference #:  P33568 (UniProtKB)
Alt. Names/Synonyms: pp105; pRb; Rb; Rb-1; Rb1; retinoblastoma 1; Retinoblastoma 1 (including osteosarcoma); Retinoblastoma-associated protein
Gene Symbols: Rb1
Molecular weight: 105,025 Da
Basal Isoelectric point: 7.97  Predict pI for various phosphorylation states
CST Pathways:  G1/S Checkpoint  |  Protein Acetylation
Select Structure to View Below


Protein Structure Not Found.

Cross-references to other databases:  AlphaFold  |  STRING  |  Reactome  |  BioGPS  |  Pfam  |  Phospho.ELM  |  NetworKIN  |  UniProtKB  |  Entrez-Gene  |  GenPept  |  Ensembl Gene  |  NURSA