Figures & data
Figure 1 Summary of the main regulators of the TGF-β pathway.
Abbreviatons: TGF-β, transforming growth factor beta; Smad, second messenger protein; ALKs, activin-like kinases.
Notes: Briefly, TGF-β binds to receptor type 2 and phosphorylates the type 1 receptor, whose main isoform is termed ALK-4 (activin-like kinase). This kinase phosphorylates and activates Smad2 or Smad3, which forms a heterodimer with Smad4, and internalizes into the nucleus to regulate gene expression. TGF-β can also act by means of non-Smad mediators, such as p38 MAP kinase and Small GTPases, like RhoA. Cytoskeleton and receptor endocytosis are additional mechanisms to regulate the TGF-β signaling. Gene expression can also be eventually modified by micro-RNAs.
