1mjs
MH2 domain of transcriptional factor SMAD3
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OverviewOverview
Smad3 transduces the signals of TGF-betas, coupling transmembrane receptor kinase activation to transcriptional control. The membrane-associated molecule SARA (Smad Anchor for Receptor Activation) recruits Smad3 for phosphorylation by the receptor kinase. Upon phosphorylation, Smad3 dissociates from SARA and enters the nucleus, in which its transcriptional activity can be repressed by Ski. Here, we show that SARA and Ski recognize specifically the monomeric and trimeric forms of Smad3, respectively. Thus, trimerization of Smad3, induced by phosphorylation, simultaneously activates the TGF-beta signal by driving Smad3 dissociation from SARA and sets up the negative feedback mechanism by Ski. Structural models of the Smad3/SARA/receptor kinase complex and Smad3/Ski complex provide insights into the molecular basis of regulation.
About this StructureAbout this Structure
1MJS is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
ReferenceReference
Smad3 allostery links TGF-beta receptor kinase activation to transcriptional control., Qin BY, Lam SS, Correia JJ, Lin K, Genes Dev. 2002 Aug 1;16(15):1950-63. PMID:12154125
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