IndraLab

"Mechanistically, Trabid forms a complex with Twist1 and specifically cleaves RNF8-induced K63-linked poly-ubiquitin chains from Twist1, which enhances the association of Twist1 with β-TrCP1 and allows for subsequent K48-linked ubiquitination of Twist1."

"To elucidate the mechanisms by which Trabid suppresses Twist1, we firstly examined the interaction between Trabid and Twist1."

"It was observed that GST-full-length (FL) Trabid and Trabid (1–354) strongly interacted with Twist1, whereas GST-Trabid (355–708) showed no interaction (Fig.  xref ), indicating that the N-terminal of Trabid should contain a primary interaction domain for Twist1."

"It suggests that Trabid-Twist1 inverse regulation in HCC was associated with reduced survival, and that Trabid downregulation in combination with RNF8 or Twist1 overexpression is a stronger predictor of poor survival than Trabid alone (Fig.  xref )."

"Thus, we concluded that Trabid directly interacts with Twist1."

"We demonstrate the following: (1) Trabid expression is significantly downregulated in HCC cell lines and two independent cohorts of HCC patients’ tissues; (2) Trabid expression is negatively correlated with pathological grading, recurrence, and poor survival; (3) Reintroduction of Trabid in HCC cells significantly decreases HCC growth and pulmonary metastasis; (4) The inhibitory effect of Trabid on HCC development occurs at least partially through regulation of Twist1 activity; (5) Trabid forms a complex with Twist1 and specifically cleaves RNF8-induced K63-linked poly-ubiquitin chains from Twist1, which enhances the association of Twist1 with β-TrCP1 and allows for subsequent K48-linked ubiquitination of Twist1; (6) AKT-mediated phosphorylation at Ser78/Thr117 is essential for the role of Trabid in negatively regulating Twist1 signaling; and (7) Twist1 negatively regulates the promoter activity of Trabid, indicating a double-negative feedback loop."

"Chromatin immunoprecipitation (ChIP) further confirmed that Twist1 directly binds to the Trabid promoter in HCC cells (Fig.  xref ) and clinical HCC tissues (Fig.  xref )."