Zeng W, Zhang J, Chen B
National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100005, China.
Zhonghua Yi Xue Za Zhi. 2001 Nov 10;81(21):1316-20.
To obtain the nucleotide sequence and deduced amino acid sequence of cholesteryl ester transfer protein (CETP) cDNA of tree shrew, mammalian insusceptible to atherosclerosis.
The first strand of cDNA of tree shrew was obtained from its liver. The sequence of tree shrew CETP cDNA was obtained by using techniques of switching mechanism at 5' end of RNA transcript (SMART) and rapid amplification of cDNA end (RACE), The CETP amino acid sequence was deduced from this cDNA and its primary and secondary structures were predicted by using DNAMAN, a software of molecular biology. Results The tree shrew CETP cDNA sequence covers 1636 bp, including a 178 bp fragment at the 3' of untranslated region and a 1458 bp fragment in the coding region, coding the complete sequence of mature tree shrew CETP except the initiator methionine. There are 477 amino acids in its mature protein, one amino acid more than that in human beings, with an extra Gly318. The homology of tree shrew CETP and human CETP and rabbit CETP is 88% and 82% respectively judged by comparing the amino acid sequence of tree shrew CETP and those of human beings and rabbit. The regions concerning the CETP function of binding and transferring neutral lipids in tree shrew CETP amino acid sequence are highly conservative. However, there is a deletion of N-linked glycosylation site at Asn342 in tree shrew protein that may increase the ability of removing peripheral cholesterol and cholesteryl ester.
The glycosylation in tree shrew CETP may be one of the mechanisms of insusceptibility to atherosis of tree shrew.
获取对动脉粥样硬化不易感的哺乳动物——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。
从树鼩肝脏中获取其cDNA第一链。利用RNA转录本5'端开关机制（SMART）和cDNA末端快速扩增（RACE）技术获得树鼩CETP cDNA序列。从该cDNA推导CETP氨基酸序列，并使用分子生物学软件DNAMAN预测其一级和二级结构。结果树鼩CETP cDNA序列全长1636 bp，包括3'非翻译区178 bp片段和编码区1458 bp片段，编码除起始甲硫氨酸外的成熟树鼩CETP完整序列。其成熟蛋白有477个氨基酸，比人类多1个氨基酸，多了一个Gly318。通过比较树鼩CETP与人类及兔的氨基酸序列，树鼩CETP与人类CETP及兔CETP的同源性分别为88%和82%。树鼩CETP氨基酸序列中与结合和转运中性脂质的CETP功能相关区域高度保守。然而，树鼩蛋白在Asn342处存在N-连接糖基化位点缺失，这可能增强其清除外周胆固醇和胆固醇酯的能力。
树鼩CETP中的糖基化可能是树鼩对动脉粥样硬化不易感的机制之一。
