Cell Signaling Technology

Product Pathways - Cell Cycle / Checkpoint

Phospho-ENSA (Ser67)/ARPP19 (Ser62) Antibody #5240

Applications Reactivity Sensitivity MW (kDa) Source
W H R (M) Endogenous 15 Rabbit

Applications Key:  W=Western Blotting
Reactivity Key:  H=Human  M=Mouse  R=Rat
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-ENSA (Ser67)/ARPP19 (Ser62) Antibody recognizes endogenous levels of ENSA and ARPP19 proteins only when phosphorylated at Ser67 and Ser62, respectively.

Source / Purification

Polyclonal antibodies are produced by immunizing animals with a synthetic peptide corresponding to residues surrounding Ser67/Ser62 of human ENSA/ARPP19 protein. Antibodies are purified by protein A and peptide affinity chromatography.

Western Blotting

Western Blotting

Western blot analysis of extracts from HeLa cells, untreated (-) or treated (+) with thymidine (2 mM, 16 hr) followed by release into nocodazole (100 ng/ml, 24 hr), using Phospho-ENSA (Ser67)/ ARPP19 (Ser62) Antibody (upper) or ENSA Antibody #8770 (lower).

Background

Mitotic control is important for normal growth, development, and maintenance of all eukaryotic cells. Research studies have demonstrated that inappropriate control of mitosis can lead to genomic instability and cancer (reviewed in 1,2). A regulator of mitosis, Greatwall kinase (Gwl), was first identified in Drosophila melanogaster (3). Subsequent studies showed that, based on sequence homology and function, microtubule-associated serine/threonine kinase-like (MASTL) is the human ortholog of Gwl (4). Regulation of MASTL/Gwl activation has been shown to be critical for the correct timing of mitosis. Research studies have shown that Gwl is activated by hyperphosphorylation (5). The phosphorylation of human Gwl at Thr194 and Thr207 by active cyclin B1-cdc2 leads to possible autophosphorylation at Ser875 (Ser883 in Xenopus), which stabilizes the kinase. Activated Gwl phosphorylates α-Endosulfine (ENSA) and cAMP-regulated phosphoprotein 19 (ARPP19) at Ser67 and Ser62, respectively. Phosphorylated ENSA and ARPP19 inhibit the activity of the B55 subunit-associated form of protein phosphatase 2A (PP2A-B55), allowing for complete phosphorylation of mitotic substrates by cyclin B1-cdc2 and mitotic entry. When Gwl is inactivated, PP2A-B55 reactivates, which leads to dephosphorylation of cyclin B1-cdc2 and mitotic exit (5,6, reviewed in 7).

  1. Eichhorn, P.J. et al. (2009) Biochim Biophys Acta 1795, 1-15.
  2. Norbury, C. and Nurse, P. (1992) Annu Rev Biochem 61, 441-70.
  3. Yu, J. et al. (2004) J Cell Biol 164, 487-92.
  4. Voets, E. and Wolthuis, R.M. (2010) Cell Cycle 9, 3591-601.
  5. Blake-Hodek, K.A. et al. (2012) Mol Cell Biol 32, 1337-53.
  6. Vigneron, S. et al. (2011) Mol Cell Biol 31, 2262-75.
  7. Lorca, T. and Castro, A. (2012) Oncogene 32, 537-543.

Application References

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Companion Products

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

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