| Autor: |
Hisamatsu, H, Shimbara, N, Saito, Y, Kristensen, P, Hendil, K B, Fujiwara, T, Takahashi, E, Tanahashi, N, Tamura, T, Ichihara, A, Tanaka, K |
| Zdroj: |
The Journal of Experimental Medicine; April 1996, Vol. 183 Issue: 4 p1807-1816, 10p |
| Abstrakt: |
Interferon (IFN) gamma induces replacements of the proteasomal subunits X and Y by LMP7 and LMP2, respectively, resulting in an alteration of the proteolytic specificity. We found a third pair of proteasome subunits expressed reciprocally in response to IFN-gamma. Molecular cloning of a cDNA encoding one subunit designated as Z, downregulated by IFN-gamma, showed that it is a novel proteasomal subunit with high homology to MECL1, which is markedly induced by IFN-gamma. Thus, IFN-gamma induces subunit replacements of not only X and Y by LMP7 and LMP2, respectively, but also of Z by MECL1, producing proteasomes responsible for immunological processing of endogenous antigens. When processed from their precursors, three pairs of the 10 homologous, but distinct, beta-type subunits of eukaryotic proteasomes, that is, X/LMP7, Y/LMP2, and Z/MECL1, have an NH2-terminal threonine residue, assumed to be part of a catalytic center. These findings suggest that the altered molecular organization of the proteasome induced by IFN-gamma may be responsible for acquisition of its functional change. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
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