Cell Signaling Technology

Product Pathways - Cell Cycle / Checkpoint

Phospho-Cyclin B1 (Ser133) (9E3) Rabbit mAb #4133

Applications Reactivity Sensitivity MW (kDa) Isotype
W IP H Endogenous 58 Rabbit IgG

Applications Key:  W=Western Blotting  IP=Immunoprecipitation
Reactivity Key:  H=Human
Species cross-reactivity is determined by western blot. Species enclosed in parentheses are predicted to react based on 100% sequence homology.

Protocols

Specificity / Sensitivity

Phospho-Cyclin B1 (Ser133) (9E3) Rabbit mAb detects endogenous levels of cyclin B1 protein only when phosphorylated at Ser133.

Source / Purification

Monoclonal antibody is produced by immunizing animals with a synthetic phosphopeptide corresponding to residues surrounding Ser133 of human cyclin B1.

Western Blotting

Western Blotting

Western blot analysis of extracts from HeLa cells, treated with hydroxyurea or nocodazole for 24 hours, using Phospho-Cyclin B1 (Ser133) (9E3) Rabbit mAb (upper) or Cyclin B1 (U152) Mouse mAb #4135 (lower).

Background

Cyclins are a family of proteins that activate specific cyclin-dependent kinases required for progression through the cell cycle. The entry of all eukaryotic cells into mitosis is regulated by activation of cdc2/cdk1 at the G2/M transition. This activation is a multi-step process that begins with the binding of the regulatory subunit, cyclin B1, to cdc2/cdk1 to form the mitosis-promoting factor (MPF). MPF remains in the inactive state until phosphorylation of cdc2/cdk1 at Thr161 by cdk activating kinase (CAK) (1,2) and dephosphorylation of cdc2/cdk1 at Thr14/Tyr15 by cdc25C (3-5). Four cyclin B1 phosphorylation sites (Ser126, 128, 133, and 147) are located in the cytoplasmic retention signal (CRS) domain and are thought to regulate the translocation of cyclin B1 to the nucleus at the G2/M checkpoint, promoting nuclear accumulation and initiation of mitosis (6-9). While MPF itself can phosphorylate Ser126 and Ser128, polo-like kinase 1 (PLK1) phosphorylates cyclin B1 preferentially at Ser133 and possibly at Ser147 (6,10). At the end of mitosis, cyclin B1 is targeted for degradation by the anaphase-promoting complex (APC), allowing for cell cycle progression (11). Research studies have shown that cyclin B1 is overexpressed in breast, prostate, and non-small cell lung cancers (12-14).

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  7. Li, J. et al. (1997) Proc Natl Acad Sci U S A 94, 502-7.
  8. Hagting, A. et al. (1999) Curr Biol 9, 680-9.
  9. Takizawa, C.G. and Morgan, D.O. (2000) Curr Opin Cell Biol 12, 658-65.
  10. Jackman, M. et al. (2003) Nat Cell Biol 5, 143-8.
  11. Gong, D. and Ferrell, J.E. (2010) Mol Biol Cell 21, 3149-61.
  12. Mashal, R.D. et al. (1996) Cancer Res 56, 4159-63.
  13. Kawamoto, H. et al. (1997) Am J Pathol 150, 15-23.
  14. Soria, J.C. et al. (2000) Cancer Res 60, 4000-4.

Application References

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Companion Products

Rabbit Monoclonals Produced Using Epitomics® Technology, U.S. Patent No. 5,675,063.

For Research Use Only. Not For Use In Diagnostic Procedures.

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