First Author | Nagai T | Year | 1998 |
Journal | J Biol Chem | Volume | 273 |
Issue | 9 | Pages | 5358-65 |
PubMed ID | 9478996 | Mgi Jnum | J:46244 |
Mgi Id | MGI:1197406 | Doi | 10.1074/jbc.273.9.5358 |
Citation | Nagai T, et al. (1998) Regulation of NF-E2 activity in erythroleukemia cell differentiation. J Biol Chem 273(9):5358-65 |
abstractText | The erythroid transcription factor NF-E2 is an obligate heterodimer composed of two different subunits (p45 and p18), each containing a basic region-leucine zipper DNA binding domain, and it plays a critical role in erythroid differentiation as an enhancer-binding protein for expression of the beta-globin gene. We show here that dimethyl sulfoxide treatment of wild-type murine erythro-leukemia cells, but not a mutant clone of dimethyl sulfoxide-resistant cells, increases NF-E2 activity significantly, which involves both up-regulation of DNA binding and transactivation activities. Both activities were reduced markedly by treatment of cells with 2-aminopurine but not by genistein. Activation of the Ras-Raf-MAP kinase signaling cascade increased NF-E2 activity significantly, but this was suppressed when MafK was overexpressed. Domain analysis revealed an activation domain in the NH2-terminal region of p45 and a suppression domain in the basic region-leucine zipper of MafK. These findings indicate that induction of NF-E2 activity is essential for erythroid differentiation of murine erythroleukemia cells, and serine/threonine phosphorylation may be involved in this process. In addition, they also suggest that a MafK homodimer can suppress transcription, not only by competition for the DNA binding site, but also by direct inhibition of transcription. Hence, MafK may function as an active transcription repressor. |