| First Author | Na SY | Year | 1999 |
| Journal | J Biol Chem | Volume | 274 |
| Issue | 40 | Pages | 28491-6 |
| PubMed ID | 10497212 | Mgi Jnum | J:120488 |
| Mgi Id | MGI:3706640 | Doi | 10.1074/jbc.274.40.28491 |
| Citation | Na SY, et al. (1999) Bcl3, an IkappaB protein, stimulates activating protein-1 transactivation and cellular proliferation. J Biol Chem 274(40):28491-6 |
| abstractText | Bcl3, an IkappaB protein, was originally isolated as a putative proto-oncogene in a subset of B cell chronic lymphocytic leukemias. Bcl3 was subsequently shown to associate tightly with and transactivate the NFkappaB p50 or p52 homodimer. Herein, we show that Bcl3 stimulates the activating protein-1 (AP-1) transactivation, either alone or in conjunction with transcription integrators steroid receptor coactivator-1 and CREB-binding protein/p300. The C-terminal 158 residues of Bcl3 exhibited an autonomous transactivation function and interacted with specific subregions of the AP-1 components c-Jun and c-Fos, CREB-binding protein/p300, and steroid receptor coactivator-1, as demonstrated by the yeast and mammalian two-hybrid tests as well as glutathione S-transferase pull-down assays. In addition, anti-HA antibody co-precipitated c-Jun from HeLa cells co-expressing c-Jun and HA-tagged Bcl3, consistent with the idea that Bcl3 directly associates with AP-1 in vivo. Furthermore, microinjection of Bcl3 expression vector into Rat-1 fibroblast cells significantly enhanced DNA synthesis and expression of c-jun, one of the cellular target genes of AP-1. These results suggest that Bcl3 may directly participate in the tumorigenesis processes as a novel transcription coactivator of the mitogenic transcription factor AP-1 in vivo. |
