Function
SMAD7 inhibits TGF-β signaling by preventing formation of Smad2/Smad4 complexes which initiate the TGF-β signaling. It interacts with activated TGF-β type I receptor therefore block the association, phosphorylation and activation of Smad2. By occupying type I receptors for Activin and bone morphogenetic protein (BMP), it also plays a role in negative feedback of these pathways.
Upon TGF- β treatment, Smad7 binds to discrete regions of Pellino-1 via distinct regions of the Smad MH2 domains. The interaction block formation of the IRAK1-mediated IL-1R/TLR signaling complex therefore abrogates NF-κB activity, which subsequently causes reduced expression of pro-inflammatory genes.
While Smad7 is induced by TGF-β, it is also induced by other stimuli, such as epidermal growth factor (EGF), interferon-γ and tumor necrosis factor (TNF)-α. Therefore it provides a cross-talk between TGF-β signaling and other cellular signaling pathways.
Read more about this topic: Mothers Against Decapentaplegic Homolog 7
Famous quotes containing the word function:
“Of all the inhabitants of the inferno, none but Lucifer knows that hell is hell, and the secret function of purgatory is to make of heaven an effective reality.”
—Arnold Bennett (1867–1931)
“The intension of a proposition comprises whatever the proposition entails: and it includes nothing else.... The connotation or intension of a function comprises all that attribution of this predicate to anything entails as also predicable to that thing.”
—Clarence Lewis (1883–1964)
“The function of the actor is to make the audience imagine for the moment that real things are happening to real people.”
—George Bernard Shaw (1856–1950)