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Product Usage Information

Storage: Supplied in 10 mM sodium HEPES (pH 7.5), 150 mM NaCl, 100 µg/ml BSA, 50% glycerol and less than 0.02% sodium azide. Store at –20°C. Do not aliquot the antibody.

Specificity / Sensitivity

Phospho-Smad3 (Ser423/425) (D12E11) Rabbit mAb recognizes endogenous levels of Smad3 protein when phosphorylated at Ser422 only, at both Ser423 and Ser425, or at Ser422, Ser423, and Ser425. This antibody also weakly recognizes the equivalent phospho-residues of Smad2 protein (Ser464, Ser465, and Ser467).

Source / Purification

Monoclonal antibody is produced by immunizing animals with a synthetic phosphopeptide corresponding to residues surrounding Ser422/423/425 of human Smad3 protein.

Members of the Smad family of signal transduction molecules are components of a critical intracellular pathway that transmit 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).

1.  Heldin, C.H. et al. (1997) Nature 390, 465-71.

2.  Attisano, L. and Wrana, J.L. (1998) Curr Opin Cell Biol 10, 188-94.

3.  Derynck, R. et al. (1998) Cell 95, 737-40.

4.  Massagué, J. (1998) Annu Rev Biochem 67, 753-91.

5.  Whitman, M. (1998) Genes Dev 12, 2445-62.

6.  Wu, G. et al. (2000) Science 287, 92-7.

7.  Attisano, L. and Wrana, J.L. (2002) Science 296, 1646-7.

8.  Moustakas, A. et al. (2001) J Cell Sci 114, 4359-69.

Entrez-Gene Id 4088
Swiss-Prot Acc. P84022

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Phospho-Smad3 (Ser423/425) (D12E11) Rabbit mAb