Rabbit polyclonal antibody to Smad2/3 (S2)

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. 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.