Cell Signaling Technology

Product Pathways - Cell Cycle / Checkpoint

PLK1 (208G4) Rabbit mAb #4513

Applications Reactivity Sensitivity MW (kDa) Isotype
W IP H R Mk Endogenous 62 Rabbit IgG

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

Protocols

Specificity / Sensitivity

PLK1 (208G4) Rabbit mAb detects endogenous levels of of total PLK1 protein.

Source / Purification

Monoclonal antibody is produced by immunizing animals with a synthetic peptide corresponding to residues near the carboxy terminus of human PLK1.

Western Blotting

Western Blotting

Western blot analysis of GSK-PLK1 fusion protein and extracts from HeLa, COS and PC12 cells, using PLK1 (208G4) Rabbit mAb.

Background

At least 4 distinct polo-like kinases exist in mammalian cells: PLK1, PLK2, PLK3, and PLK4/SAK (1). PLK1 apparently plays many roles during mitosis, particularly in regulating mitotic entry and exit. The mitosis promoting factor (MPF), cdc2/cyclin B1, is activated by dephosphorylation of cdc2 (Thr14/Tyr15) by cdc25C. PLK1 phosphorylates cdc25C at Ser198 and cyclin B1 at Ser133 causing translocation of these proteins from the cytoplasm to the nucleus (2-5). PLK1 phosphorylation of Myt1 at Ser426 and Thr495 has been proposed to inactivate Myt1, one of the kinases known to phosphorylate cdc2 at Thr14/Tyr15 (6). Polo-like kinases also phosphorylate the cohesin subunit SCC1, causing cohesin displacement from chromosome arms that allow for proper cohesin localization to centromeres (7). Mitotic exit requires activation of the anaphase promoting complex (APC) (8), a ubiquitin ligase responsible for removal of cohesin at centromeres, and degradation of securin, cyclin A, cyclin B1, Aurora A, and cdc20 (9). PLK1 phosphorylation of the APC subunits Apc1, cdc16, and cdc27 has been demonstrated in vitro and has been proposed as a mechanism by which mitotic exit is regulated (10,11).Substitution of Thr210 with Asp has been reported to elevate PLK1 kinase activity and delay/arrest cells in mitosis, while a Ser137Asp substitution leads to S-phase arrest (12). Additionally, while DNA damage has been found to inhibit PLK1 kinase activity, the Thr210Asp mutant is resistant to this inhibition (13). PLK1 has been reported to be phosphorylated in vivo at Ser137 and Thr210 in mitosis, and DNA damage prevents phosphorylation at these sites (14).

  1. Nigg, E.A. (1998) Curr. Opin. Cell Biol. 10, 776-783.
  2. Toyoshima-Morimoto, F. et al. (2002) EMBO Rep. 3, 341-348.
  3. Toyoshima-Morimoto, F. et al. (2001) Nature 410, 215-220.
  4. Peter, M. et al. (2002) EMBO Rep. 3, 551-556.
  5. Jackman, M. et al. (2003) Nat. Cell Biol. 5, 143-148.
  6. Nakajima, H. et al. (2003) J. Biol. Chem. 278, 25277-25280.
  7. Sumara, I. et al. (2002) Mol. Cell 9, 515-525.
  8. Hauf, S. et al. (2001) Science 293, 1320-1323.
  9. Peters, J.M. (1999) Exp. Cell Res. 248, 339-349.
  10. Kraft, C. et al. (2003) EMBO J. 22, 6598-6609.
  11. Kotani, S. et al. (1998) Mol. Cell 1, 371-380.
  12. Jang, Y.J. et al. (2002) J Biol Chem 277, 44115-20.
  13. Smits, V.A. et al. (2000) Nat Cell Biol 2, 672-6.
  14. Tsvetkov, L. and Stern, D.F. (2005) Cell Cycle 4, 166-71.

Application References

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Companion Products

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

This product is intended for research purposes only. The product is not intended to be used for therapeutic or diagnostic purposes in humans or animals.

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