Source:http://linkedlifedata.com/resource/umls/id/C1515163
NCI: TGF-beta regulates growth and proliferation of cells, blocking growth of many cell types. The TGF-beta receptor includes type 1 and type 2 subunits that are serine-threonine kinases and that signal through the SMAD family of transcriptional regulators. Defects in TGF-beta signaling, including mutation in SMADs, have been associated with cancer in humans. Prior to activation, receptor regulated SMADs are anchored to the cell membrane by factors like SARA (SMAD Anchor for Receptor Activation) that brings the SMADs into proximity of the TGF receptor kinases. Binding of TGF induces phosphorylation and activation of the TGF-beta R1 receptor by the TGF-beta R2 receptor. The activated TGF-beta R1 phosphorylates SMAD2 and SMAD3, which bind to the SMAD4 mediator to move into the nucleus and form complexes that regulate transcription. SMADs regulate transcription in several ways, including binding to DNA, interacting with other transcription factors, and interacting with transcription corepressors and coactivators