Rb operates in the midst of the cell cycle clock apparatus. Its main role is to act as a signal transducer connecting the cell cycle clock with the transcriptional machinery (Ref.1). It plays an important role in the Rb/ E2F pathway in cell proliferation, cell fate determination, and cancer (Ref.2). Cellular senescence is a stable form of cell cycle arrest that limits proliferation of damaged cells and act as a natural barrier to cancer progression. A distinct heterochromatic structure that accumulates in senescent human fibroblasts, designated as SAHF (Senescence-Associated Heterochromatic Foci). SAHF formation coincides with recruitment of heterochromatin proteins and the Rb protein to E2F-responsive promoters and is associated with the stable repression of E2F target genes. Both SAHF formation and the silencing of E2F target genes depended on the integrity of the Rb pathway and do not occur in reversibly arrested cells (Ref.3). Rb activates transcription of the c-Jun gene through the SP1-binding site within the c-Jun promoter Roesch A, et al. (2005) Mod Pathol. 18(4): 565-572.Chadee DN, et al. (2004) Nat Cell Biol. 6(8): 770-776.Knudsen ES, et al. (1997) Mol Cell Biol. 17(10): 5771-5783.Knudsen ES, et al. (1996) J Biol Chem. 271(14): 8313-8320.
Host
Rabbit
Immunogen
Peptide sequence around aa.805~809 (Y-I-S-P-L) derived from Human Rb.
Involvement In Disease
Childhood cancer retinoblastoma (RB); Bladder cancer (BLC); Osteogenic sarcoma (OSRC)
Raised In
Rabbit
Reactivity
Human, Mouse, Rat
Regulatory
RUO
Relevance
Rb operates in the midst of the cell cycle clock apparatus. Its main role is to act as a signal transducer connecting the cell cycle clock with the transcriptional machinery (Ref.1). It plays an important role in the Rb/ E2F pathway in cell proliferation, cell fate determination, and cancer (Ref.2). Cellular senescence is a stable form of cell cycle arrest that limits proliferation of damaged cells and act as a natural barrier to cancer progression. A distinct heterochromatic structure that accumulates in senescent human fibroblasts, designated as SAHF (Senescence-Associated Heterochromatic Foci). SAHF formation coincides with recruitment of heterochromatin proteins and the Rb protein to E2F-responsive promoters and is associated with the stable repression of E2F target genes. Both SAHF formation and the silencing of E2F target genes depended on the integrity of the Rb pathway and do not occur in reversibly arrested cells (Ref.3). Rb activates transcription of the c-Jun gene through the SP1-binding site within the c-Jun promoter
Roesch A, et al. (2005) Mod Pathol. 18(4): 565-572. Chadee DN, et al. (2004) Nat Cell Biol. 6(8): 770-776. Knudsen ES, et al. (1997) Mol Cell Biol. 17(10): 5771-5783. Knudsen ES, et al. (1996) J Biol Chem. 271(14): 8313-8320.
Species
Homo Sapiens (Human)
Specificity
The antibody detects endogenous level of total Rb protein.
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 (By similarity). 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.
Pathway
Cell cycle Cellular senescence
Protein Families
Retinoblastoma protein (RB) family
Tissue Specificity
Expressed in the retina.
Buffer
Supplied at 1.0mg/mL in phosphate buffered saline (without Mg2+ and Ca2+), pH 7.4, 150mM NaCl, 0.02% sodium azide and 50% glycerol.
Form
Supplied at 1.0mg/mL in phosphate buffered saline (without Mg2+ and Ca2+), pH 7.4, 150mM NaCl, 0.02% sodium azide and 50% glycerol.
Format
liquid
Purification
Antibodies were produced by immunizing rabbits with synthetic peptide and KLH conjugates. Antibodies were purified by affinity-chromatography using epitope-specific peptide.
Purity
Antibodies were produced by immunizing rabbits with synthetic peptide and KLH conjugates. Antibodies were purified by affinity-chromatography using epitope-specific peptide.
Storage
Upon receipt, store at -20°C or -80°C. Avoid repeated freeze.