Replacement of proteasome subunits X and Y by LMP7 and LMP2 induced by interferon-gamma for acquirement of the functional diversity responsible for antigen processing.
Article Details
- CitationCopy to clipboard
Akiyama K, Kagawa S, Tamura T, Shimbara N, Takashina M, Kristensen P, Hendil KB, Tanaka K, Ichihara A
Replacement of proteasome subunits X and Y by LMP7 and LMP2 induced by interferon-gamma for acquirement of the functional diversity responsible for antigen processing.
FEBS Lett. 1994 Apr 18;343(1):85-8.
- PubMed ID
- 8163024 [ View in PubMed]
- Abstract
Proteasomes catalyze the non-lysosomal, ATP-dependent selective breakdown of ubiquitinated proteins and are thought to be responsible for MHC class I-restricted antigen presentation. Recently, we reported that gamma interferon (IFN-gamma) induced not only marked synthesis of the MHC-encoded proteasome subunits LMP2 and LMP7, but also almost complete loss of two unidentified proteasome subunits tentatively designated as X and Y in various human cells. Here, we show that subunit X is a new proteasomal subunit highly homologous to LMP7, and that subunit Y is identical to the LMP2-related proteasomal subunit delta. Thus, IFN-gamma appears to induce subunit replacements of X and Y by LMP7 and LMP2, respectively, producing 'immuno-proteasomes' with the functional diversity responsible for processing of endogenous antigens.