RESUMEN
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
RESUMEN
Smad4, a common-mediator of Smads, plays a central role in forming complexes with receptor-phosphorylated Smads, and then transduces transforming growth factor (TGF)-ß signals into the nuclei. Although many cellular factors are involved in TGF-ß induced epithelial-to-mesenchymal transition (EMT) and cell migration, very little is known with the mechanism of Smad4 regulation on pro-oncogenes response by TGF-ß. Herein, we demonstrate the interaction of Sentrin-specific protease 2 (SENP2) with Smad4 through SENP2 residue 363~400. The same segment is also important for desumoylation of Smad4, and able to relieve sumoylation-mediated TGF-ß repression. The SENP2363~400 segment is critical for TGF-ß-induced cell migration, which is correlated with SENP2363~400 deletion mutant failed to increase matrix metalloproteinase (MMP)-9 and EMT marker gene expression. Moreover, our results suggest that the interaction and desumoylation between SENP2 and Smad4 promote cell migration in triple-negative breast cancer cells. Altogether, our data show how SENP2 regulates its substrate for desumoylation, and also the role of SENP2 in TGF-ß induced cancer cell migration.
Asunto(s)
Carcinogénesis/metabolismo , Carcinogénesis/patología , Cisteína Endopeptidasas/metabolismo , Movimiento Celular , Humanos , Unión Proteica , Transducción de Señal/efectos de los fármacos , Proteína Smad4/metabolismo , Esferoides Celulares/metabolismo , Esferoides Celulares/patología , Especificidad por Sustrato , Sumoilación , Factor de Crecimiento Transformador betaRESUMEN
The movement of some plant viruses are accomplished by three proteins encoded by a triple gene block (TGB). The second protein (TGBp2) in the block is a transmembrane protein. This study was aimed to unravel the mechanism underlying the relatively inefficient cell-to-cell movement of Bamboo mosaic virus (BaMV) caused by amino acid substitutions for the three Cys residues, Cys-109, Cys-112 and Cys-119, at the C-terminal tail of TGBp2. Results from confocal microscopy revealed that substitutions of the three Cys residues of TGBp2, especially Cys-109 and Cys-112, would reduce the efficiency of TGBp2- and TGBp3-dependent PD localization of TGBp1. Moreover, there is an additive effect of the substitutions on reducing the efficiency of PD localization of TGBp1. These results indicate that the Cys residues in the C-terminal tail region of TGBp2 participate in the TGBp2- and TGBp3-dependent PD localization of TGBp1, and thus influence the cell-to-cell movement capability of BaMV.