References
PMID:22286770
The inhibitory Smad7 mRNA is repressed by MIR106B, MIR93, MIR25.
Smad7 antagonizes TGF-b signaling through multiple mechanisms, including binding to TGFBR1 and interfering with recruitment and downstream phosphorylation and activation of Smad2 and Smad3.
Smad7 also functions to recruit E3 ubiquitin ligases to TGRFBR1, resulting in its degradation.
Repression of Smad7 therefore activates TGF-beta signaling.