Retinoblastoma (RB1) Human 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: Tumor suppressor; Nuclear receptor co-regulator; Transcription, coactivator/corepressor; Oncoprotein

Chromosomal Location of Human Ortholog: 13q14.2

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

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

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

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