Cell Signaling Technology

Product Pathways - TGF-beta/Smad Signaling

Phospho-Smad2 (Ser245/250/255) Antibody #3104

Applications Reactivity Sensitivity MW (kDa) Source
W H M (R) Endogenous 60 Rabbit

Applications Key:  W=Western Blotting
Reactivity Key:  H=Human  M=Mouse  R=Rat
Species cross-reactivity is determined by Western blot.

Protocols

Specificity / Sensitivity

Phospho-Smad2 (Ser245/250/255) Antibody detects endogenous levels of Smad2 only when phosphorylated at serines 245, 250 or 255.

Source / Purification

Polyclonal antibodies are produced by immunizing rabbits with a synthetic phospho-peptide (KLH-coupled) corresponding to residues surrounding serines 245/250/255 of Smad2. Antibodies are purified by protein A and peptide affinity chromatography.

Western Blotting

Western Blotting

Western blot analysis of extracts from HeLa cells, mock transfected or transfected with Smad2 or Smad3 and treated with TPA (200 nM) or TGF-beta (100 ng/ml) for 30 minutes, using Phospho-Smad2 (Ser245/250/255) Antibody.

Western Blotting

Western Blotting

Western blot analysis of extracts from 293 and HeLa cells, untreated or TPA-treated (200 nM for 30 minutes) using Phospho-Smad2 (Ser245/250/255) Antibody (upper) or Smad2 Antibody (lower).

Background

Members of the Smad family of signal transduction molecules are components of a critical intracellular pathway that transmits TGF-β signals from the cell surface into the nucleus. Three distinct classes of Smads have been defined: the receptor-regulated Smads (R-Smads), which include Smad1, 2, 3, 5 and 8, the common-mediator Smad (co-Smad), Smad4, and the antagonistic or inhibitory Smads (I-Smads), Smad6 and 7 (1-5). Activated type I receptors associate with specific R-Smads and phosphorylate them on a conserved carboxy-terminal SSXS motif. The phosphorylated R-Smad dissociates from the receptor and forms a heteromeric complex with the co-Smad (Smad4), allowing translocation of the complex to the nucleus. Once in the nucleus, Smads can target a variety of DNA binding proteins to regulate transcriptional responses (6-8).

Oncogenic Ras antagonizes TGF-beta signaling and inhibits the nuclear accumulation of Smad2 and Smad3, which may be explained through MAP kinase dependent phosphorylation of these Smads (9).Cell stimulation with EGF leads to phosphorylation of Smad2 at a cluster of serine-proline sites within its linker region, including Ser245, 250, and 255 (9).

  1. Heldin, C.H. et al. (1997) Nature 390, 465-471.
  2. Attisano, L. and Wrana, J.L. (1998) Curr. Opin. Cell Biol. 10, 188-194.
  3. Derynck, R. et al. (1998) Cell 95, 737-740.
  4. Massague, J. (1998) Annu. Rev. Biochem. 67, 753-791.
  5. Whitman, M. et al. (1998) Genes Dev. 12, 2445-2462.
  6. Wrana, J. (2000) Science 23, 1-9.
  7. Attisano, L. and Wrana, J. (2002) Science 296, 1646-1647.
  8. Moustakas, A. et al. (2001) J. Cell Sci. 114, 4359-4369.
  9. Kretzschmar, M. et al. (1999) Genes Dev. 13, 804-816.

Application References

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Companion Products

This product is for in vitro research use only and is not intended for use in humans or animals. This product is not intended for use as therapeutic or in diagnostic procedures.

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