Smad4 polyclonal antibody

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