Purified from rabbit serum by sequential epitope-specific chromatography. The antibody has been negatively preadsorbed using a non-phosphopeptide corresponding to the site of phosphorylation to remove antibody that is reactive with non-phosphorylated Rb protein. The final product is generated by affinity chromatography using a Rb-derived peptide that is phosphorylated at threonine 821.
The application notes include recommended starting dilutions; optimal dilutions/concentrations should be determined by the end user.
1/1000. Detects a band of approximately 120 kDa (predicted molecular weight: 106 kDa).
Use at an assay dependent concentration.
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.
Expressed in the retina.
Involvement in disease
Childhood cancer retinoblastoma Bladder cancer Osteogenic sarcoma
Belongs to the retinoblastoma protein (RB) family.
The Pocket domain binds to the threonine-phosphorylated domain C, thereby preventing interaction with heterodimeric E2F/DP transcription factor complexes.
Phosphorylated by CDK6 and CDK4, and subsequently by CDK2 at Ser-567 in G1, thereby releasing E2F1 which is then able to activate cell growth. Dephosphorylated at the late M phase. SV40 large T antigen, HPV E7 and adenovirus E1A bind to the underphosphorylated, active form of pRb. Phosphorylation at Thr-821 and Thr-826 promotes interaction between the C-terminal domain C and the Pocket domain, and thereby inhibits interactions with heterodimeric E2F/DP transcription factor complexes. Dephosphorylated at Ser-795 by calcineruin upon calcium stimulation. CDK3/cyclin-C-mediated phosphorylation at Ser-807 and Ser-811 is required for G0-G1 transition. Phosphorylated by CDK1 and CDK2 upon TGFB1-mediated apoptosis. N-terminus is methylated by METTL11A/NTM1 (By similarity). Monomethylation at Lys-810 by SMYD2 enhances phosphorylation at Ser-807 and Ser-811, and promotes cell cycle progression. Monomethylation at Lys-860 by SMYD2 promotes interaction with L3MBTL1. Acetylation at Lys-873 and Lys-874 regulates subcellular localization, at least during keratinocytes differentiation.
Protein phosphatase 1 regulatory subunit 130 antibody
RB transcriptional corepressor 1 antibody
RB1 gene antibody
Retinoblastoma 1 antibody
Retinoblastoma suspectibility protein antibody
Retinoblastoma-associated protein antibody
Western blot - Anti-Rb (phospho T821) antibody (ab4787)
Peptide Competition: Cell extracts prepared from Jurkat cells in high growth phase were resolved by SDS-PAGE on a 10% Tris-glycine gel and transferred to PVDF. Membranes were incubated with 0.50 µg/mL ab4787, following prior incubation in the: absence of the phosphopeptide immunogen (1), a generic phosphothreonine containing peptide (2), the non phosphopeptide corresponding to the phosphopeptide immunogen (3), or the presence of the phosphopeptide immunogen (4). After washing, membranes were incubated with goat F(ab’)2 anti-rabbit IgG alkaline phosphatase and bands were detected using the Tropix WesternStar detection method. The data show that only the phosphopeptide corresponding to this site blocks the antibody signal, demonstrating the specificity of the ab4787 antibody for this epitope. Peptide Competition: Cell extracts prepared from Jurkat cells in high growth phase were resolved by SDS-PAGE on a 10% Tris-glycine gel and transferred to PVDF. Membranes were in
Immunocytochemistry/ Immunofluorescence - Anti-Rb (phospho T821) antibody (ab4787)This image is courtesy of an anonymous Abreview
ab4787 staining Rb (phospho T821) in mouse B cell line cells by ICC/IF (Immunocytochemistry/immunofluorescence). Cells were fixed with paraformaldehyde, permeabilized with 0.1% Triton X-100 in PBS for 10 minutes at room temperature and blocked with 3% BSA + 2.5% serum in TBS for 2 hours at room temperature. Samples were incubated with primary antibody (1/300 in TBS-T + 1% serum + 3% BSA) for 16 hours at 4°C. An Alexa Fluor® 546-conjugated goat anti-rabbit IgG (H+L) polyclonal (1/500) was used as the secondary antibody.