Cell Signaling Technology

Product Pathways - MAPK Signaling

Phospho-MEK1 (Ser298) Antibody #9128

Applications Reactivity Sensitivity MW (kDa) Source
W H M R Mk (Dg) Endogenous 45 Rabbit

Applications Key:  W=Western Blotting
Reactivity Key:  H=Human  M=Mouse  R=Rat  Mk=Monkey  Dg=Dog
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-MEK1 (Ser298) Antibody detects endogenous levels of MEK1 phosphorylated at serine 298. This antibody does not cross-react with phosphorylated MEK2.

Source / Purification

Polyclonal antibodies are produced by immunizing animals with a synthetic phosphopeptide corresponding to residues surrounding Ser298 of human MEK1. Antibodies are purified by protein A and peptide affinity chromatography.

Western Blotting

Western Blotting

Western blot analysis of extracts from C2C12, C6 and COS cells, untreated or PMA-treated, using Phospho-MEK1 (Ser298) Antibody (upper) or MEK1 Antibody #9124 (lower). In lane 3, the C2C12 lysate was treated with alkaline phosphatase (CIP) to show the phospho-specificity of the antibody.

Background

MEK1 and MEK2, also called MAPK or Erk kinases, are dual-specificity protein kinases that function in a mitogen activated protein kinase cascade controlling cell growth and differentiation (1-3). Activation of MEK1 and MEK2 occurs through phosphorylation of two serine residues at positions 217 and 221, located in the activation loop of subdomain VIII, by Raf-like molecules. MEK1/2 is activated by a wide variety of growth factors and cytokines and also by membrane depolarization and calcium influx (1-4). Constitutively active forms of MEK1/2 are sufficient for the transformation of NIH/3T3 cells or the differentiation of PC-12 cells (4). MEK activates p44 and p42 MAP kinase by phosphorylating both threonine and tyrosine residues at sites located within the activation loop of kinase subdomain VIII.

MEK1 is phosphorylated at Ser298 by PAK1, which facilitates signal transduction from Raf to MEK1 and Erk2 (5-7). MEK1 is also phosphorylated by cdk5 at Thr286 in mitotic cells, causing negative feedback of the p44/42 MAP kinase pathway (8).

  1. Crews, C.M. et al. (1992) Science 258, 478-480.
  2. Alessi, D.R. et al. (1994) EMBO J. 13, 1610-1619.
  3. Rosen, L.B. et al. (1994) Neuron 12, 1207-1221.
  4. Cowley, S. et al. (1994) Cell 77, 841-852.
  5. Xu, B. et al. (1999) J. Biol. Chem. 274, 34029-34035.
  6. Coles, L.C. and Shaw, P.E. (2002) Oncogene 21, 2236-2244.
  7. Eblen, S. T. et al. (2002) Mol. Cell. Biol. 22, 6023-6033.
  8. Sharma, P. et al. (2002) J. Biol. Chem. 277, 528-534.

Application References

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

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