MHC CLASS-II-ASSOCIATED INVARIANT CHAIN CONTAINS A SORTING SIGNAL FOR ENDOSOMAL COMPARTMENTS
MHC CLASS-II-ASSOCIATED INVARIANT CHAIN CONTAINS A SORTING SIGNAL FOR ENDOSOMAL COMPARTMENTS
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DOI：
10.1016/0092-8674(90)90137-4
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发表时间：
1990-11-16
期刊：
影响因子：
64.5
通讯作者：
DOBBERSTEIN, B
中科院分区：
文献类型：
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作者：
BAKKE, O;DOBBERSTEIN, B
不变链（li）是一种跨膜蛋白，与内质网中的MHC II类分子相关。在MHC II类阴性的CV1细胞中表达的li显示其获得复合型寡糖侧链并保留在内体隔室中。为了寻找分选信号，我们从li的胞质N-末端进行了渐进性缺失。删除11个氨基酸残基导致蛋白质仍然被分选并保留在内体囊泡中，而删除15个或更多个氨基酸残基导致蛋白质驻留在质膜中。因此，氨基酸12-15对于细胞内转运至内体隔室至关重要。由于li在细胞内与MHC II类分子相关，因此提出li决定这些分子的细胞内转运途径。
The invariant chain (li) is a transmembrane protein that associates with the MHC class II molecules in the endoplasmic reticulum. Expression of li in MHC class II-negative CV1 cells showed that is acquired complex-type oligosaccharide side chains and was retained in endosomal compartments. To search for a sorting signal, we made progressive deletions from the cytoplasmic N-terminus of li. Deleting 11 amino acid residues resulted in a protein that was still sorted and retained in endosomal vesicles, whereas deletion of 15 or more amino acid residues resulted in a protein that became resident in the plasma membrane. Amino acids 12-15 are thus essential for intracellular transport to endosomal compartments. As li is intracellularly associated with the MHC class II molecules, it is proposed that li determines the intracellular transport route of these molecules.