ER aminopeptidases generate a unique pool of peptides for MHC class I molecules
ER aminopeptidases generate a unique pool of peptides for MHC class I molecules
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DOI：
10.1038/89800
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发表时间：
2001-07-01
影响因子：
30.5
通讯作者：
Shastri, N
中科院分区：
文献类型：
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作者：
Serwold, T;Gaw, S;Shastri, N
我们在这里定义了内质网（ER）中蛋白酶的特异性和重要性，这些蛋白酶产生主要组织相容性复合体（MHC）类分子呈现的肽。我们发现，除了脯氨酸外，氨肽酶有效地修剪了内质网中抗原前体nh2末端的所有残基，并导致了X-P-X-n肽的积累。氨基肽酶抑制剂阻断内质网中的肽修剪，因此，产生装载肽的MHC分子。因此，内质网中的肽修剪是MHC I类抗原加工途径的关键步骤，也解释了为什么许多MHC类分子显示带有X-P-X的肽的悖论。尽管与抗原加工相关的转运体无法从细胞质中转运这些肽，但Motif。
We define here the specificity and significance of proteases in the endoplasmic reticulum (ER) that generate peptides for presentation by major histocompatibility complex (MHC) class molecules. We show that aminopeptidases efficiently trimmed all residues except proline that flank the NH2-termini of antigenic precursors in the ER and caused an accumulation of X-P-X-n peptides. An aminopeptidase inhibitor blocked peptide trimming in the ER and, consequently, the generation of peptide-loaded MHC molecules. Peptide trimming in the ER is therefore a key step in the MHC class I antigen-processing pathway and also explains the paradox of why many MHC class molecules display peptides with the X-P-X. motif despite the inability of the transporter associated with antigen processing to transport such peptides from the cytoplasm.