REPLACEMENT OF PROTEASOME SUBUNIT-X AND SUBUNIT-Y BY LMP7 AND LMP2 INDUCED BY INTERFERON-GAMMA FOR ACQUIREMENT OF THE FUNCTIONAL DIVERSITY RESPONSIBLE FOR ANTIGEN-PROCESSING
REPLACEMENT OF PROTEASOME SUBUNIT-X AND SUBUNIT-Y BY LMP7 AND LMP2 INDUCED BY INTERFERON-GAMMA FOR ACQUIREMENT OF THE FUNCTIONAL DIVERSITY RESPONSIBLE FOR ANTIGEN-PROCESSING
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DOI：
10.1016/0014-5793(94)80612-8
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发表时间：
1994-04-18
期刊：
影响因子：
3.5
通讯作者：
ICHIHARA, A
中科院分区：
文献类型：
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作者：
AKIYAMA, K;KAGAWA, S;ICHIHARA, A
蛋白酶体催化泛素化蛋白的非溶酶体、ATP依赖性选择性分解，并被认为负责MHC I类限制性抗原呈递。最近，我们报道，γ干扰素（IFN-γ）诱导不仅显着的MHC编码的蛋白酶体亚基LMP 2和LMP 7的合成，但也几乎完全丧失了两个未知的蛋白酶体亚基暂定为X和Y在各种人类细胞。在这里，我们表明，X亚基是一个新的蛋白酶体亚基LMP 7高度同源，和亚基Y是相同的LMP 2相关的蛋白酶体亚基δ。因此，IFN-γ似乎分别通过LMP 7和LMP 2诱导X和Y的亚基替换，产生具有负责内源性抗原加工的功能多样性的“免疫蛋白酶体”。
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.