IRF-1 mediates upregulation of LMP7 by IFN-gamma and concerted expression of immunosubunits of the proteasome.
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Namiki S, Nakamura T, Oshima S, Yamazaki M, Sekine Y, Tsuchiya K, Okamoto R, Kanai T, Watanabe M
IRF-1 mediates upregulation of LMP7 by IFN-gamma and concerted expression of immunosubunits of the proteasome.
FEBS Lett. 2005 May 23;579(13):2781-7. Epub 2005 Apr 20.
- PubMed ID
- 15907481 [ View in PubMed]
- Abstract
An immunoproteasome subunit low molecular weight protein 7 (LMP7) plays critical roles in major histocompatibility complex class I antigen processing; however, the mechanism for its expression has remained unclear. We demonstrate that interferon (IFN) regulatory factor-1 (IRF-1) has a pivotal role in IFN-gamma-dependent LMP7 expression, as was shown for the other two immunosubunits. A tetracycline-inducible system for IRF-1 revealed its function in the LMP7 expression, and a genomic region functionally interacting with IRF-1 was also determined. Furthermore, the role of IRF-1 in IFN-gamma-inducible LMP7 transcription was confirmed by employing small interfering RNA experiments and IRF-1-/- mice. These results suggest that IRF-1 acts as a master regulator for the concerted expression of immunoproteasome components.