Cell Signaling Technology

Product Pathways - Cell Cycle / Checkpoint

Phospho-Rb (Ser780) Antibody #9307

Applications Reactivity MW (kDa) Source
W IP E-P H M R Mk Z 110 Rabbit

Applications Key:  W=Western Blotting  IP=Immunoprecipitation  E-P=ELISA (Peptide)
Reactivity Key:  H=Human  M=Mouse  R=Rat  Mk=Monkey  Z=Zebra Fish
Species enclosed in parentheses are predicted to react based on 100% sequence homology. Species cross-reactivity is determined by Western blot.

Specificity / Sensitivity

Phospho-Rb (Ser780) Antibody detects endogenous levels of Rb only when phosphorylated at Ser780. The antibody does not cross-react with Rb phosphorylated at other sites.

Source / Purification

Polyclonal antibodies are produced by immunizing rabbits with a synthetic phospho-peptide (KLH-coupled) corresponding to residues surrounding Ser780 of human Rb. Antibodies are purified by protein A and peptide affinity chromatography.

Western Blotting

Western Blotting

Western blot analysis of extracts from human fibroblasts synchronized by serum deprivation, using Phospho-Rb (Ser780) Antibody. Cells were synchronized for 24 hours then released by addition of serum and harvested at the times indicated. Cell cycle progression was verified by cyclin analysis and FACS. (Provided by John Boylan, Dupont/Merck, Delaware.)

Background

The retinoblastoma tumor suppressor protein, Rb, regulates cell proliferation by controlling progression through the restriction point within the G1-phase of the cell cycle (1). Rb has three functionally distinct binding domains and interacts with critical regulatory proteins including the E2F family of transcription factors, c-Abl tyrosine kinase and proteins with a conserved LXCXE motif (2-4). Cell cycle-dependent phosphorylation by a CDK inhibits Rb target binding and allows cell cycle progression (5). Rb inactivation and subsequent cell cycle progression likely requires an initial phosphorylation by cyclin D-CDK4/6 followed by cyclin E-CDK2 phosphorylation (6). Specificity of different CDK/cyclin complexes has been observed in vitro (6-8) and cyclin D1 is required for Ser780 phosphorylation in vivo (9).

  1. Sherr, C.J. (1996) Science 274, 1672-1677.
  2. Nevins, J.R. et al. (1992) Science 258, 424-429.
  3. Welch, P.J. and Wang, J.Y. (1993) Cell 75, 779-790.
  4. Hu, Q.J. et al. (1990) EMBO J. 9, 1147-1155.
  5. Knudsen, E.S. and Wang, J.Y. (1997) Mol. Cell. Biol. 17, 5771-5783.
  6. Lundberg, A.S. and Weinberg, R.A. (1998) Mol. Cell. Biol. 18, 753-761.
  7. Connell-Crowley, L. et al. (1997) Mol. Cell. Biol. 8, 287-301.
  8. Kitagawa, M. et al. (1996) EMBO J. 15, 7060-7069.
  9. Geng, Y. et al. (2001) Proc. Natl. Acad. Sci. USA 98, 194-199.

Application References

Have you published research involving the use of our products? If so we'd love to hear about it. Please let us know!

Companion Products

Product Pathways

Drug Discovery Tools

Featured Technologies

Protein Classes