| First Author | Uchiumi F | Year | 2004 |
| Journal | Biochem Biophys Res Commun | Volume | 321 |
| Issue | 2 | Pages | 355-63 |
| PubMed ID | 15358184 | Mgi Jnum | J:91301 |
| Mgi Id | MGI:3046409 | Doi | 10.1016/j.bbrc.2004.06.152 |
| Citation | Uchiumi F, et al. (2004) Characterization of Smubp-2 as a mouse mammary tumor virus promoter-binding protein. Biochem Biophys Res Commun 321(2):355-63 |
| abstractText | A cDNA encoding a rat Smubp-2 has been cloned from a lambdagt11 library by South-Western blot screening using a 50-bp tannic acid responsive element [J. Biol. Chem. 273 (1998) 12499] of the mouse mammary tumor virus (MMTV) promoter region as a probe. The full-length cDNA encodes a protein with a predicted size of 108 kDa. Northern blot analysis revealed that the gene expression of Smubp-2 is comparatively high in testis, moderate in brain, and low in other tissues. The recombinant Smubp-2 protein was expressed as a GST- or Trx-fusion protein in Escherichia coli and purified by affinity column chromatography. Gel mobility shift competition analysis indicated that the recombinant Smubp-2 protein binds to region II (containing the ACTG-motif) in the 50-bp element in the MMTV promoter. A transient transfection assay of the Smubp-2 expression vector with MMTV promoter-containing Luciferase (Luc) reporter plasmids into mouse cells suggested that Smubp-2 is a negative transcription factor. Furthermore, the MMTV promoter activity was suppressed in cells expressing high levels of Smubp-2. Insertion of the 50-bp element upstream of the SV40 promoter negatively responded to the induced expression of Smubp-2. These results suggest that the negative transcriptional effect of Smubp-2 arises from its binding to the 50-bp element located in the MMTV promoter region. |
