βarrestin2 interacts with TβRII to regulate Smad-dependent and Smad-independent signal transduction

► βarrestin2 interacts with TβRII in the absence of TβRIII. ► βarrestin2 traffics with TβRII and enhances the interaction of TβRII with SARA. ► βarrestin2 siRNA increases cell surface TβRII levels, Smad2 and p38 phosphorylation. ► βarrestin2 siRNA-dependent phosphorylation of p38 correlates with increased apoptosis.