| First Author | Kokura K | Year | 2003 |
| Journal | J Biol Chem | Volume | 278 |
| Issue | 22 | Pages | 20133-9 |
| PubMed ID | 12646588 | Mgi Jnum | J:196118 |
| Mgi Id | MGI:5486566 | Doi | 10.1074/jbc.M210855200 |
| Citation | Kokura K, et al. (2003) The Ski-binding protein C184M negatively regulates tumor growth factor-beta signaling by sequestering the Smad proteins in the cytoplasm. J Biol Chem 278(22):20133-9 |
| abstractText | Ski is a transcriptional co-repressor and is involved in the negative regulation of tumor growth factor-beta (TGF-beta) signaling. To understand more fully the role of Ski in TGF-beta signaling, we searched for novel Ski-interacting proteins. The identified C184M protein consists of 189 amino acids and contains the leucine-rich region. An association between Ski and C184M involving the leucine-rich region of C184M and the C-terminal coiled-coil motif of Ski was confirmed by glutathione S-transferase pull-down and immunoprecipitation assays. The C184M protein is located in the cytosol, and the C184M and Ski signals are co-localized in the cytoplasm when C184M was co-expressed with Ski in CV-1 cells. The cytoplasmic C184M-Ski complex inhibited the nuclear translocation of Smad2. Consistent with this, the activity of promoter containing the Smad-binding sites was repressed by C184M, and the TGF-beta-induced growth inhibition of mink lung Mv1Lu cells was attenuated by the ectopic expression of C184M. Thus, C184M inhibits TGF-beta signaling in concert with Ski. In hepatocytes, which express significant levels of C184M, the Ski signals were found only in the cytoplasm, supporting the notion that C184M forms a complex with Ski in the cytosol. |
