Anti-phospho-Retinoblastoma (Ser249, Thr252) (Rb)

Rb is a 110kD tumor suppressor gene which functions as a negative regulator of the cell cycle by interacting with transcription factors including E2F-1, PU.1, ATF-2, UBF, Elf-1 and c-Abl. This ability to alter transcription is regulated by phosphorylation catalyzed by the cyclin-dependent protein kinases (cdks). Phosphorylation of serine 249 and threonine 252 is catalyzed by Cyclin Dcdk4. Rb contains at least 16 consensus sequences for cdk phosphorylation, but the significance of many of these sites is unclear. Phosphorylation by cdk4 appears to prime Rb for its subsequent phosphorylation by cdk2 and inhibits HDAC binding, DNA acetylation and Rb active repression. Applications: Suitable for use in Western Blot. Other applications not tested. Recommended Dilution: Western Blot: 1:1000, Optimal dilutions to be determined by the researcher. Positive Control: Jurkat cells in high growth phase. Storage and Stability: May be stored at 4°C for short-term only. Aliquot to avoid repeated freezing and thawing. Store at -20°C. Aliquots are stable for at least 12 months. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap.