I 类 MHC 抗原呈递：折叠、组装和肽装载
中文名称
通路描述
与其他糖蛋白不同，MHC 类 I 分子的正确折叠不足以触发其从内质网（ER）退出，它们只有在完成肽装载后才退出。此处描述的是抗原呈递过程，包括 MHC 类 I 分子的折叠、组装和肽装载。新合成的 MHC 类 I 重链（HC）最初在几种辅助蛋白（calnexin, BiP, ERp57）的帮助下折叠，然后与β-2微球蛋白（B2M）结合。该 MHC:B2M 异二聚体进入肽装载复合物（PLC），该复合物包括钙联蛋白（calreticulin）、内质网驻留蛋白 57（ERp57）、抗原加工转运蛋白（TAP）和 tapasin。从泛素 - 蛋白酶体降解产生的肽段通过 TAP 转运进入 ER。这些肽段进一步由内质网相关氨基肽酶（ERAP）修剪，并加载到 MHC 类 I 分子上。具有高亲和力肽段的稳定 MHC 类 I 三聚体通过高尔基体从 ER 转运到细胞表面。
英文描述
Antigen Presentation: Folding, assembly and peptide loading of class I MHC Unlike other glycoproteins, correct folding of MHC class I molecules is not sufficient to trigger their exit from the ER, they exit only after peptide loading. Described here is the process of antigen presentation which consists of the folding, assembly, and peptide loading of MHC class I molecules. The newly synthesized MHC class I Heavy Chain (HC) is initially folded with the help of several chaperones (calnexin, BiP, ERp57) and then binds with Beta-2-microglobulin (B2M). This MHC:B2M heterodimer enters the peptide loading complex (PLC), a multiprotein complex that includes calreticulin, endoplasmic reticulum resident protein 57 (ERp57), transporter associated with antigen processing (TAP) and tapasin. Peptides generated from Ub-proteolysis are transported into the ER through TAP. These peptides are further trimmed by ER-associated aminopeptidase (ERAP) and loaded on to MHC class I molecules. Stable MHC class I trimers with high-affinity peptide are transported from the ER to the cell surface by the Golgi apparatus.
所含基因
24 个基因