THE LONG AMINO-TERMINAL TAIL DOMAIN OF ANNEXIN-XI IS NECESSARY FOR ITS NUCLEAR-LOCALIZATION
THE LONG AMINO-TERMINAL TAIL DOMAIN OF ANNEXIN-XI IS NECESSARY FOR ITS NUCLEAR-LOCALIZATION
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DOI：
10.1006/abbi.1995.1216
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发表时间：
1995-04-01
影响因子：
3.9
通讯作者：
HIDAKA, H
中科院分区：
文献类型：
--
作者：
MIZUTANI, A;WATANABE, N;HIDAKA, H
膜联蛋白XI是一种新发现的膜联蛋白，主要存在于大鼠胚胎成纤维细胞的细胞核中。分子中没有典型的核定位信号（NLS）。为了确定其核定位的区域，构建了一系列突变体和嵌合cDNA。这些突变体和嵌合蛋白在COS-7细胞中短暂表达，并通过间接免疫荧光显微镜测定其亚细胞分布。野生型膜联蛋白XI主要位于细胞核内。n端尾部结构域（残基3-196）的缺失改变了蛋白质从细胞核向细胞质的分布，而c端核心结构域（残基208-504）的缺失仍然保持了蛋白质向细胞核的分选。另外三个在n端区域缺乏60-80个氨基酸的突变体（残基分别为3-61、61-115和115-197）不再有效地导入细胞核。此外，大肠杆菌β -半乳糖苷酶多肽只有在与膜联蛋白XI的整个n端区域（残基1-207）融合时才能有效地定位到细胞核上，而不是与部分n端区域融合。在原代培养的大鼠肝细胞中，膜联蛋白XI分布在细胞质中，而不在细胞核中。这些结果表明，膜联蛋白XI的整个n端尾结构域对于其核定位是必要和充分的，并且可能以细胞类型特异性的方式发挥NLS的作用。(C) 1995学术出版社，Inc。
Annexin XI is a newly identified annexin which localizes mainly in the nucleus of rat embryonic fibroblasts. There are no typical nuclear localization signals (NLS) in the molecule. To define the region responsible for its nuclear localization, a series of mutants and chimeric cDNA were constructed. These were transiently expressed in COS-7 cells, and the subcellular distributions of the mutants and chimeric proteins were determined by indirect immunofluorescence microscopy. Wild-type annexin XI was located predominantly within the nucleus. Deletion of the N-terminal tail domain (residues 3-196) changed the distribution of the protein from the nucleus to the cytoplasm whereas deletion of the C-terminal core domain (residues 208-504) still kept the protein sorting to the nucleus. Three other mutants lacking 60-80 amino acids in the N-terminal region (residues 3-61, 61-115, and 115-197, respectively) no longer efficiently imported into the nucleus. Furthermore, Escherichia coli beta-galactosidase polypeptide was efficiently localized to the nucleus only when fused with the whole N-terminal region of annexin XI (residues 1-207), not with part of the N-terminal region. In primary cultured rat hepatocytes, annexin XI was distributed in the cytoplasm but not in the nucleus. These results suggest that the whole N-terminal tail domain of annexin XI is necessary and sufficient for its nuclear localization, and may function as NLS in a cell-type specific manner. (C) 1995 Academic Press, Inc.