Target: Detects endogenous total Rb protein (not phosphorylation-specific).
Immunogen: Synthetic peptide around amino acids 778–782 (T-L-S-P-I), encompassing Ser780.
Host/Clonality: Rabbit/polyclonal.
Applications:
Western blotting (WB): 1:500–1:1000 dilution.
Immunohistochemistry (IHC): 1:50–1:100 dilution.
Species Reactivity: Human, mouse, rat.
Purification: Affinity chromatography using epitope-specific peptide.
Formulation: Supplied at 1.0 mg/mL in phosphate-buffered saline (PBS) with sodium azide and 50% glycerol.
The Rb protein acts as a transcriptional repressor of E2F1 target genes, arresting the cell cycle in G1 phase when underphosphorylated. Its phosphorylation by cyclin-dependent kinases (CDKs) releases E2F1, enabling S-phase entry .
Phospho-Ser780 antibodies (e.g., ABIN675294, PA5-114632) detect phosphorylated Rb, critical for studying its activation in cell cycle progression . For example, UV-irradiated NIH/3T3 cells show strong phospho-Ser780 signals, validating its role in DNA damage response .
Rb recruits histone methyltransferases (e.g., SUV39H1) to maintain chromatin structure and repress transcription through histone H4 'Lys-20' trimethylation .
Rb binds viral proteins like SV40 large T antigen, disrupting its tumor suppressor activity .
Rb dysfunction is implicated in cancers (e.g., breast, colon, prostate) and viral infections . Phospho-Ser780 antibodies enable functional studies of Rb activation in disease contexts .