I-SMADs reside in the nucleus presumably to be sequestered from the BMP2:receptor complex and thus avoid inappropriate silencing of the signalling pathway. Upon activation of the signalling pathway, I-SMADs exit the nucleus and are recruited to the signalling BMP2:receptor complex. I-SMADs directly bind to the so-called L45 loop of the type I receptor, the site of binding of R-SMADs. Thus, I-SMADs competitively inhibit the activation/phosphorylation of R-SMADs.
Miyazono, K, Murakami, G, Imamura, T, Takaoka, K, Watabe, T
Yoshida, M, Miyazono, K, Yoneda, Y, Tajima, Y, Shinomiya, K, Goto, K, Sekimoto, T, Imamura, T
© 2023 Reactome
