Cloning and characterization of cholesteryl ester transfer transfer protein isolated from the tree shrew.
Cloning and characterization of cholesteryl ester transfer transfer protein isolated from the tree shrew.
复制标题
DOI：
--
复制
发表时间：
2003-06
影响因子：
6.1
通讯作者：
W. Zeng;Jian Zhang;Bao-sheng Chen;Gang Wu;H. Xue
中科院分区：
文献类型：
--
作者：
W. Zeng;Jian Zhang;Bao-sheng Chen;Gang Wu;H. Xue
目的获得树鼩胆固醇酯转运蛋白（CETP）cDNA的核苷酸序列及推导的氨基酸序列。方法利用RNA转录本5'端转换机制（SMART）和cDNA末端快速扩增（RACE）技术，从树CETP cDNA第一链扩增得到树CETP的cDNA序列。从cDNA序列中推导出CETP的氨基酸序列，并预测其一级和二级结构。结果获得的树鼩 CETP cDNA序列（GenBank登录号AF 334033）全长1636 bp，其中3'端非翻译区178 bp，编码区1458 bp。前24 bp编码部分信号肽。成熟蛋白由477个氨基酸组成，比人类版本长一个氨基酸（Gly 318）。与其它动物CETP的氨基酸序列比较，树鼩与人和兔CETP的同源性分别为88%和82%。该蛋白质具有极强的疏水性，因为它含有许多疏水残基，特别是在C-末端，这与其在中性脂质转移中的功能一致。与中性脂质结合和转移有关的氨基酸残基高度保守。树鼩 CETP蛋白在Asn 342处缺失一个N-糖基化位点，可能通过增加其转运胆固醇酯的活性参与外周血胆固醇和胆固醇酯的清除。结论树鼩 CETP可能存在糖基化修饰，这可能是其抗动脉粥样硬化的分子机制之一。
OBJECTIVE To obtain the nucleotide sequence and deduced amino acid sequence of cholesteryl ester transfer protein (CETP) cDNA from the tree shrew (Tupaia glis). METHODS The cDNA sequence of the tree shrew CETP was obtained by utilizing the technique of switching mechanism at 5' end of RNA transcript (SMART) and rapid amplification of cDNA end (RACE) from the first strand of the cDNA. The amino acid sequence of CETP was deduced from the cDNA sequence and its primary and secondary structures were predicted. RESULTS The sequence of CETP cDNA from tree shrew (GenBank accession number AF334033) covers 1636 bp, including 178 bp at the 3' end of the untranslated region and a 1458 bp fragment in a coding region, which provides the complete sequence of mature tree shrew CETP, although not the initiator methionine. The first 24 bp encodes a partial signal peptide. The mature protein consists of 477 amino acids and is longer than the human version by one amino acid (Gly318). Comparing this amino acid sequence with those of other animals' CETPs, the identity between tree shrew and human and rabbit CETP is 88% and 82%, respectively. The protein is extremely hydrophobic as it contains many hydrophobic residues, especially at the C-terminal, consistent with its function in the transfer of neutral lipids. The amino acid residues concerning with binding and transferring neutral lipids are highly conserved. There is a deletion of an N-linked glycosylation site at Asn342 in the tree shrew CETP protein that may participate in the removal of peripheral cholesterol and cholesteryl ester by increasing its activity of transferring cholesteryl ester. CONCLUSION The possible glycosylation in the tree shrew CETP may be involved in the molecular mechanism of its insusceptibility to atherosclerosis.