Anti-phospho-Rb (Ser780)

In 1X PBS, pH 7.4, with 0.09% sodium azide. RB1 likely acts as a regulator of other genes. It forms a complex with adenovirus E1A and with SV40 large T antigen, acts as a tumor suppressor, and may bind and modulate functionally certain cellular proteins with which T and E1A compete for pocket binding. RB1 is a potent inhibitor of E2F-mediated trans-activation, and also recruits and targets histone methyltransferase SUV39H1 leading to epigenetic transcriptional repression. This protein inhibits the intrinsic kinase activity of TAF1. Defects in RB1 are the cause of childhood cancer retinoblastoma (RB), a congenital malignant tumor that arises from the nuclear layers of the retina. Defects in RB1 are also a cause of bladder cancer and osteogenic sarcoma. Protein function: 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, SUV420H1 and SUV420H2, 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. 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. [The UniProt Consortium]