A RECYCLING PATHWAY BETWEEN THE ENDOPLASMIC-RETICULUM AND THE GOLGI-APPARATUS FOR RETENTION OF UNASSEMBLED MHC CLASS-I MOLECULES
A RECYCLING PATHWAY BETWEEN THE ENDOPLASMIC-RETICULUM AND THE GOLGI-APPARATUS FOR RETENTION OF UNASSEMBLED MHC CLASS-I MOLECULES
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DOI：
10.1038/352441a0
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发表时间：
1991-08-01
期刊：
影响因子：
64.8
通讯作者：
KLAUSNER, RD
中科院分区：
文献类型：
--
作者：
HSU, VW;YUAN, LC;KLAUSNER, RD
I类主要组织相容性复合体（MHC）分子的组装涉及两种不同多肽（重链和轻链）与肽抗原的相互作用。已经鉴定了合成两条链但由于组装和运输失败而在其表面上表达低水平的MHC I类分子的细胞系1。 我们现在报告说，虽然在这些细胞中的I类分子的表观稳态分布是在内质网（ER），分子实际上是再循环之间的ER和高尔基体，而不是保留在ER。这解释了I类分子无法通过分泌途径。I类分子似乎没有被高尔基体酶修饰，这表明蛋白质在回收过程中没有到达高尔基体。但形态学和亚细胞分级证据表明，它们通过顺式高尔基体或高尔基体相关的细胞器，我们假设这是回收细胞器。我们称之为“顺式高尔基体网络”的这个隔室因此将是一个选择蛋白质返回ER的分选细胞器。
ASSEMBLY of Class I major histocompatibility complex (MHC) molecules involves the interaction of two distinct polypeptides (the heavy and light chains) with peptide antigen. Cell lines synthesizing both chains but expressing low levels of MHC class I molecules on their surface as a result of a failure in assembly and transport have been identified 1. We now report that although the apparent steady-state distribution in these cells of class I molecules is in the endoplasmic reticulum (ER), the molecules in fact are recycled between the ER and Golgi, rather than retained in the ER. This explains the failure of class I molecules to negotiate the secretory pathway. Class I molecules do not seem to be modified by Golgi enzymes, suggesting that the proteins do not reach the Golgi apparatus during recycling. But morphological and subcellular fractionation evidence indicates that they pass through the cis Golgi or a Golgi-associated organelle, which we postulate to be the recycling organelle. This compartment, which we call the 'cis-Golgi network', would thereby be a sorting organelle that selects proteins for return to the ER.