The MHC class II-associated invariant chain contains two endosomal targeting signals within its cytoplasmic tail.
The MHC class II-associated invariant chain contains two endosomal targeting signals within its cytoplasmic tail.
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MHC II 类相关不变链在其细胞质尾部包含两个内体靶向信号。
DOI：
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发表时间：
1993
影响因子：
4
通讯作者：
Bernhard Dobberstein
中科院分区：
文献类型：
--
作者：
Jean Pieters;Oddmund Bakke;Bernhard Dobberstein
由主要组织相容性复合体（MHC）II类α和β链以及不变链（Ii）形成的寡聚复合体在内质网中组装，然后通过高尔基复合体转运至内吞途径的隔室。当Ii单独在CV1细胞中表达时，它被分选到内体。已经发现Ii胞质尾区对于靶向这些隔室是必不可少的。为了进一步表征负责内体靶向的信号，我们删除了细胞质尾部的各个片段。瞬时表达Ii突变体，并对蛋白质的细胞定位进行生化和形态学分析。发现Ii的胞质尾在其胞质尾内含有两个内体靶向序列;一个靶向序列存在于氨基酸残基12-29内，并且该区段的缺失揭示了位于前11个氨基酸残基内的第二个内体靶向序列的存在。发现该序列内位置7和8处的亮氨酸-异亮氨酸对的存在对于内体靶向是必需的。此外，这种L-I基序的存在导致Ii分子在含有溶酶体标记蛋白的大内体空泡中积累。仅含有一个内体靶向序列的野生型Ii和Ii突变体分子均从质膜迅速内化。当Ii细胞质尾融合到神经氨酸酶，一个居民质膜蛋白的跨膜区域，所产生的嵌合体（INA）被发现在含有溶酶体标记蛋白的内吞隔室。因此，Ii的胞质尾区足以靶向内吞/溶酶体途径。
The oligomeric complex formed by major histocompatibility complex (MHC) class II alpha and beta chains and invariant chain (Ii) assembles in the endoplasmic reticulum and is then transported via the Golgi complex to compartments of the endocytic pathway. When Ii alone is expressed in CV1 cells it is sorted to endosomes. The Ii cytoplasmic tail has been found to be essential for targeting to these compartments. In order to characterize further the signals responsible for endosomal targeting, we have deleted various segments of the cytoplasmic tail. The Ii mutants were transiently expressed and the cellular location of the proteins was analyzed biochemically and morphologically. The cytoplasmic tail of Ii was found to contain two endosomal targeting sequences within its cytoplasmic tail; one targeting sequence was present within amino acid residues 12-29 and deletion of this segment revealed the presence of a second endosomal targeting sequence, located within the first 11 amino acid residues. The presence of a leucine-isoleucine pair at positions 7 and 8 within this sequence was found to be essential for endosomal targeting. In addition, the presence of this L-I motif lead to accumulation of Ii molecules in large endosomal vacuoles containing lysosomal marker proteins. Both wild type Ii and Ii mutant molecules containing only one endosomal targeting sequence were rapidly internalized from the plasma membrane. When the Ii cytoplasmic tail was fused to the membrane-spanning region of neuraminidase, a resident plasma membrane protein, the resulting chimera (INA) was found in endocytic compartments containing lysosomal marker proteins. Thus the cytoplasmic tail of Ii is sufficient for targeting to the endocytic/lysosomal pathway.
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流感病毒神经氨酸酶信号锚定结构域的突变分析。
DOI：
10.1073/pnas.84.1.1
发表时间：
1987
影响因子：
11.1
作者：
Sivasubramanian,N;Nayak,DP
通讯作者：
Nayak,DP
位于多种形式的不变链（gamma、gamma 2、gamma 3）上的人类 Ia 细胞质决定簇。
DOI：
--
发表时间：
1984
期刊：
Journal of immunology (Baltimore, Md. : 1950)
影响因子：
--
作者：
Quaranta,V;Majdic,O;Stingl,G;Liszka,K;Honigsmann,H;Knapp,W
通讯作者：
Knapp,W
DOI：
10.1016/s0021-9258(18)37369-1
发表时间：
1988-12
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
S. Carlsson;J. Roth;F. Piller;Minoru Fukuda
通讯作者：
S. Carlsson;J. Roth;F. Piller;Minoru Fukuda
DOI：
10.1016/s0021-9258(18)54636-6
发表时间：
1991-11
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
M. Fukuda
通讯作者：
M. Fukuda
参与流感病毒跨膜蛋白的分选和运输的结构域和组织构象。
影响因子：
10.5
作者：
Nayak,DP;Jabbar,MA
通讯作者：
Jabbar,MA