Product Name:
RB-pT373
Product Number:
ab-pn978
Target Full Name: Retinoblastoma-associated protein 1
Target Alias: P105-Rb; Pp110; PRb
Product Type Specific: Rb phosphosite-specific antibody
Antibody Code: PN978
Antibody Target Type: Phosphosite-specific
Antibody Phosphosite: T373
Protein UniProt: P06400
Protein SigNET: RB
Antibody Type: Polyclonal
Antibody Host Species: Rabbit
Antibody Immunogen Source: Synthetic phosphopeptide patterned after human RB
Antibody Immunogen Sequence: IPPH(pT)PVR(βA)C
Antibody Immunogen Description: Corresponds to amino acid residues I369 to R376. T373 phosphorylation inhibits interaction with EF21. This is one of the major sites of in vivo phosphorylation of Rb based on ≥86 mass spectrometry reports recorded in PhosphoSitePlus. Rb is known to be phosphorylated at this site in vitro by CDK1 (CDC2), CDK2, and CDK4.
Production Method: The immunizing peptide was produced by solid phase synthesis on a multipep peptide synthesizer and purified by reverse-phase hplc chromatography. Purity was assessed by analytical hplc and the amino acid sequence confirmed by mass spectrometry analysis. This peptide was coupled to KLH prior to immunization into rabbits. New Zealand White rabbits were subcutaneously injected with KLH-coupled immunizing peptide every 4 weeks for 4 months. The sera from these animals was applied onto an agarose column to which the immunogen peptide was thio-linked. Antibody was eluted from the column with 0.1 M glycine, pH 2.5. Subsequently, the antibody solution was neutralized to pH 7.0 with saturated Tris.
Antibody Modification: Unconjugated. Contact KInexus if you are interest in having the antibody biotinylated or coupled with fluorescent dyes.
Antibody Concentration: 1 mg/ml
Storage Buffer: Phosphate buffered saline pH 7.4, 0.05% Thimerasol
Storage Conditions: For long term storage, keep frozen at -40°C or lower. Stock solution can be kept at +4°C for more than 3 months. Avoid repeated freeze-thaw cycles.
Product Use: Western blotting | Antibody microarray
Antibody Dilution Recommended: 2 µg/ml for immunoblotting
Antibody Species Reactivity: This antibody detects the target phosphoprotein in the following species due to conservation of amino acid sequence: Human | Chimpanzee | Rhesus macaque | Dog | Rat | Mouse | Platypus | Chicken.
Related Product 1: RB S249+T252 phosphorylation antibody (Cat. No.: AB-PN724)
Related Product 2: RB S807+S811 phosphorylation antibody (Cat. No.: AB-PN847)
Scientific Background: RB1 (Retinoblastoma protein) is a critical tumour suppressor protein that belongs to the retinoblastoma protein (RB) family. It acts as the "sentry" of the cell cycle, inhibiting G1-to-S phase progression to prevent uncontrolled cell division. It functions as a molecular scaffold, binding to and inhibiting transcription factors like E2F to control DNA replication and gene expression. Active, unphosphorylated Rb blocks S-phase entry by sequestering E2F. When phosphorylated by cyclin-CDK complexes (specifically cyclin D-CDK4/6), RB1 becomes inactive, releasing E2F to allow cell cycle progression by stimulation expression of genes such a c-Myc. Beyond the cell cycle, RB1 contributes to chromatin remodeling, apoptosis, differentiation, and maintaining chromosome stability. It is directly involved in heterochromatin formation by maintaining overall chromatin structure and, in particular, that of constitutive heterochromatin by stabilizing histone methylation. It recruits and targets histone methyltransferases SUV39H1, KMT5B and KMT5C, leading to epigenetic transcriptional repression. It controls histone H4 'Lys-20' trimethylation. It inhibits the intrinsic kinase activity of TAF1. It 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 (PP2B), which leads to release of the repressor complex. It features three main domains—an N-terminal domain (RBN), a central "pocket" domain, and a C-terminal domain—which act as a docking site for various proteins, including viral oncoproteins. RB1 be functionally inhibited by viral oncoproteins such as HPV E7, SV40 TAg, and Adenovirus E1A, which bind to its pocket domain, promoting cancer. As the first identified tumour suppressor, loss or mutation of the RB1 gene leads to deregulation of the cell cycle and is a hallmark of many cancers, particularly retinoblastomas. This description may include information annotated by UniProt and/or Google AI.