| First Author | Yahata T | Year | 2000 |
| Journal | J Biol Chem | Volume | 275 |
| Issue | 12 | Pages | 8825-34 |
| PubMed ID | 10722728 | Mgi Jnum | J:61379 |
| Mgi Id | MGI:1354847 | Doi | 10.1074/jbc.275.12.8825 |
| Citation | Yahata T, et al. (2000) The MSG1 non-DNA-binding transactivator binds to the p300/CBP coactivators, enhancing their functional link to the Smad transcription factors. J Biol Chem 275(12):8825-34 |
| abstractText | The MSG1 nuclear protein has a strong transcriptional activating activity but does not bind directly to DNA. When cotransfected, MSG1 enhances transcription mediated by the Smad transcription factors in mammalian cells in a manner dependent on ligand-induced Smad hetero-oligomerization. However, the mechanism of this MSG1 effect has been unknown. We now show that MSG1 directly binds to the p300/cAMP-response element-binding protein-binding protein (CBP) transcriptional coactivators, which in turn bind to the Smads, and enhances Smad-mediated transcription in a manner dependent on p300/CBP. The C-terminal transactivating domain of MSG1 is required for binding to p300/CBP and enhancement of Smad-mediated transcription; the viral VP16 transactivating domain could not substitute for it. In the N-terminal region of MSG1, we identified a domain that is necessary and sufficient to direct the specific interaction of MSG1 with Smads. We also found that the Hsc70 heat-shock cognate protein also forms complex with MSG1 in vivo, suppressing both binding of MSG1 to p300/CBP and enhancement of Smad-mediated transcription by MSG1. These results indicate that MSG1 interacts with both the DNA-binding Smad proteins and the p300/CBP coactivators through its N- and C-terminal regions, respectively, and enhances the functional link between Smads and p300/CBP. |
