E3 ubiquitin-protein ligase TRIM33 (TRIM33)

Promotes SMAD4 ubiquitination, nuclear exclusion and degradation through the ubiquitin proteasome pathway. According to PubMed:16751102, does not promote a decrease in the amount of endogenous SMAD4.

May behave as a transcriptional repressor. Inhibits the transcriptional response to TGF-beta/BMP signaling cascade.