Product Pathways - Motif Antibodies

• Antibodies for PTMScan^®
• more info
• application references

PTMScan^® Phospho-PLK Binding Motif (ST*P) Immunoaffinity Beads

Services Information

This product is not for individual sale. It is only available as a component of the PTMScan^® Proteomics System. PTMScan^® Proteomics System orders must be priced out individually. Please email us at ptmscan@cellsignal.com to receive the most accurate pricing.

Description

PTMScan^® Immunoaffinity Beads are custom preparations of motif antibodies coupled to protein A beads. They are intended only for use for PTMScan^® and are available as components of the PTMScan^® Proteomics System.

Specificity / Sensitivity

PTMScan^® Phospho-PLK Binding Motif (ST*P) Immunoaffinity Beads detect and capture endogenous levels of peptide derived from protease digested cellular proteins containing Ser-phospho-Thr-Pro motif. The antibody has minor cross reactivity with phospho Thr-Pro motif. (U.S. Patent No's.: 6,441,140; 6,982,318; 7,259,022; 7,344,714; U.S.S.N. 11,484,485; and all foreign equivalents.)

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). In addition, 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; DNA damage prevents phosphorylation at these sites (14).

Polo-like kinases (PLKs) are Ser/Thr protein kinases that play essential roles during the cell cycle. At least four PLKs exist in mammalian cells: PLK1, PLK2, PLK3, and PLK4 (1). PLKs have a highly conserved amino-terminal kinase domain and a relatively divergent carboxy-terminal domain called the Polo-box domain (PBD). Of the four PLKs, PLK1 is the best characterized (2). PLK1 functions as a key regulator of mitotic events by phosphorylating substrate proteins on centrosomes, kinetochores, the mitotic spindle, and the midbody, and is crucial for proper progression through multiple stages of mitosis (2-4). The PBDs of PLK1 function as a phospho-Ser/Thr-binding module, recognizing the optimal recognition sequence motif Ser-[pSer/pThr]-[Pro/X] (PLK1 binding motif) (5). Binding of phosphopeptides containing Ser-[pSer/pThr]-[Pro/X] motif by the PBD in PLK1 relieves its inhibitory function on kinase activity (6). Ser-pSer/Thr-Pro peptides are phosphorylated by proline-directed kinases such as cyclin dependent kinases (CDKs). These findings imply that priming phosphorylations on substrates or docking proteins by other mitotic kinases such as CDKs may target PLK1 to its substrates and simultaneously activate its kinase activity. Ser-pThr-Pro Antibody developed by Cell Signaling Technology is a useful tool to study PLK1 binding proteins and PLK1 substrates.

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.
15. Nigg, E.A. (1998) Curr Opin Cell Biol 10, 776-83.
16. Donaldson, M.M. et al. (2001) J Cell Sci 114, 2357-8.
17. Barr, F.A. et al. (2004) Nat Rev Mol Cell Biol 5, 429-40.
18. Kishi, K. et al. (2009) Mol Cell Biol 29, 3134-50.
19. Elia, A.E. et al. (2003) Science 299, 1228-31.
20. Elia, A.E. et al. (2003) Cell 115, 83-95.

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!

---

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