The Smad family of proteins are components of the signaling pathway for the TGF-β receptor superfamily. Activated receptors associate with specific Smads and phosphorylate them at a conserved sequence in the carboxy terminus. The phosphorylated Smad forms a complex with the Smad4, and translocates to the nucleus, to regulate transcriptional responses.
TGR has developed 3 separate SureFire kits for measurement of Smads. The phospho-Smad 1 (5/8) recognizes Smad 1, and based on sequence similarity, is likely to recognize Smad 5 and Smad 8. TGR has also developed SureFire assay kits for the detection of phospho-Smad 2 and phospho-Smad 3.