Identification of bovine invariant chain (Ii) gene by nucleotide sequencing.
Identification of bovine invariant chain (Ii) gene by nucleotide sequencing.
复制标题
通过核苷酸测序鉴定牛恒定链（Ii）基因。
DOI：
10.1006/bbrc.1996.0689
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发表时间：
1996
影响因子：
3.1
通讯作者：
Y. Aida
中科院分区：
文献类型：
--
作者：
M. Niimi;Y. Nakai;Y. Aida
分离并表征了编码牛不变链（Ii）的四个重叠cDNA克隆。牛Ii cDNA克隆NI 3具有1，381-bp的插入片段，编码204个氨基酸的翻译产物。从该克隆推导的氨基酸序列显示，牛Ii基因与人Ii基因的关系比与啮齿类动物（如小鼠和大鼠）的基因的关系更密切，但与其他物种的蛋白质相比，牛Ii基因的胞外结构域的3'端缺少10个氨基酸。感兴趣的是，II类相关的不变链肽（CLIP）片段存在于由NI 3编码的蛋白质中，并且该区域与人、小鼠和大鼠编码的序列具有高度的整体相似性，这表明牛CLIP可能具有与MHC II类分子结合的CLIP生物学功能。因此，这似乎是可能的，该cDNA克隆编码的功能性产品，可能执行一个重要的功能，在MHC II类抗原呈递，如先前在小鼠和人的研究中建立。
Four overlapping cDNA clones encoding the bovine invariant chain (Ii) were isolated and characterized. The bovine Ii cDNA clone, NI3 with a 1,381-bp insert, encoded a translated product of 204 amino acids. The amino acid sequences deduced from this clone revealed that the bovine Ii gene is more closely related to human Ii gene than to genes for rodents, such as mouse and rat, but lacked 10 amino acids of the 3' end of the extracellular domain comparable to those in proteins from other species. Of interest is that the class-II-associated invariant chain peptide (CLIP) segment is present in the protein encoded by NI3, and this region exhibits a high degree of overall similarity to sequences encoded by human, mouse and rat, suggesting that bovine CLIP may have the biological function of CLIP binding to MHC class II molecules. Thus, it seems likely that this cDNA clone encodes a functional product which might perform an important function in MHC class II antigen presentation, as previously established in studies in mouse and man.