Acts as a coactivator of transcriptional activity. Required to increase TGFB1/Smad-mediated transactivation. Acts through SMAD2, SMAD3 and SMAD4 to increase transcriptional activity. Increases phosphorylation of SMAD2 and SMAD3 on their C-terminal SSXS motif, possibly through recruitment of TGFBR1. Promotes the nuclear accumulation of SMAD2, SMAD3 and SMAD4 proteins . Binds to poly(A) RNA (, ).
Subcellular locations: Nucleus, Cytoplasm, Cytoplasm, P-body
Translocates into cytoplasmic stress granules that probably correspond to P-bodies in response to oxidative stress.
Ubiquitously expressed, at various levels depending on the isoform and the tissue.