SMURF2 Protein, Human

SMURF2 Protein, functioning as an E3 ubiquitin-protein ligase, operates by accepting ubiquitin from an E2 ubiquitin-conjugating enzyme and subsequently transferring ubiquitin directly to its targeted substrates. Notably, it interacts with SMAD7 to instigate SMAD7-mediated ubiquitin-dependent degradation of the transforming growth factor beta (TGF-beta) receptor, leading to the down-regulation of TGF-beta signaling. This interaction with SMAD7 not only triggers the degradation of the TGF-beta receptor but also activates SMURF2's autocatalytic degradation, a process antagonized by the association with AIMP1. Additionally, SMURF2 forms a stable complex with TGF-beta receptor-mediated phosphorylated SMAD1, SMAD2, and SMAD3, targeting SMAD1 and SMAD2 for ubiquitination and subsequent degradation. In the context of filovirus infections such as Ebola/EBOV and Marburg/MARV, SMURF2 collaborates with the viral matrix protein VP40 to facilitate virus budding. Furthermore, SMURF2 plays a critical role in negatively regulating TGFB1-induced processes, including epithelial-mesenchymal transition and myofibroblast differentiation. This multifaceted functionality underscores the diverse regulatory roles of SMURF2 in cellular signaling and responses to infections.