Retinoblastoma-Associated Protein (RB1) Recombinant Protein

The protein encoded by this gene is a negative regulator of the cell cycle and was the first tumor suppressor gene found. The encoded protein also stabilizes constitutive heterochromatin to maintain the overall chromatin structure. The active, hypophosphorylated form of the protein binds transcription factor E2F1. Defects in this gene are a cause of childhood cancer retinoblastoma (RB), bladder cancer, and osteogenic sarcoma. [provided by RefSeq, Jul 2008]

Rb: retinoblastoma tumor suppressor protein regulates cell proliferation by controlling progression through the G1-phase restriction point. Has three distinct binding domains and interacts with regulatory proteins including the E2F family of transcription factors, c-Abl tyrosine kinase and proteins with a conserved LXCXE motif. Cell cycle-dependent phosphorylation by Cdks inhibits Rb target binding, thus allowing cell cycle progression. Recruits and targets histone methyltransferase suv39h1 leading to epigenetic transcriptional repression.

Protein type: Transcription, coactivator/corepressor; Tumor suppressor; Oncoprotein; Nuclear receptor co-regulator

Chromosomal Location of Human Ortholog: 13q14.2

Cellular Component: chromatin; nucleoplasm; nucleus; PML body; Rb-E2F complex; spindle; SWI/SNF complex; transcription elongation factor complex b

Molecular Function: androgen receptor binding; DNA binding; identical protein binding; kinase binding; phosphoprotein binding; protein binding; transcription coactivator activity; transcription factor activity; transcription factor binding; ubiquitin protein ligase binding

Biological Process: androgen receptor signaling pathway; cell cycle arrest; cell cycle checkpoint; cell division; chromatin remodeling; enucleate erythrocyte differentiation; G1/S transition of mitotic cell cycle; G1/S-specific transcription in mitotic cell cycle; gut development; maintenance of mitotic sister chromatid cohesion; mitotic cell cycle checkpoint; myoblast differentiation; negative regulation of epithelial cell proliferation; negative regulation of protein kinase activity; negative regulation of smoothened signaling pathway; negative regulation of transcription factor activity; negative regulation of transcription from RNA polymerase II promoter, mitotic; negative regulation of transcription, DNA-dependent; neurite development; neuron apoptosis; neuron maturation; neuron morphogenesis during differentiation; positive regulation of macrophage differentiation; positive regulation of mitotic metaphase/anaphase transition; positive regulation of transcription from RNA polymerase II promoter; positive regulation of transcription, DNA-dependent; Ras protein signal transduction; regulation of lipid kinase activity; regulation of mitotic cell cycle; sister chromatid biorientation; striated muscle cell differentiation; transcription, DNA-dependent; viral reproduction

Disease: Bladder Cancer; Osteogenic Sarcoma; Retinoblastoma; Small Cell Cancer Of The Lung