摘要
利用EST拼接技术、RT PCR及DNA序列测定 ,首次成功克隆了小鼠新基因mLPTS。获得的mLPTS基因片段长 12 4 4bp ,编码了一个由 332个氨基酸组成的蛋白质。该蛋白质与人的LPTS蛋白有 78%的同源性 ,LPTS基因是本实验室通过定位候选克隆策略获得的一个新的肝癌相关基因。它在肝癌组织中不表达或低表达 ,并参与细胞生长的负调控。小鼠mLPTS基因在小鼠的各个组织中都有表达 ,与人LPTS基因的表达组织分布相同。分析比较了LPTS蛋白在不同物种间的序列同源性 ,发现LPTS在进化上是高度保守的 ,是一个具有重要功能的基因。将mLPTS基因与绿色荧光蛋白EGFP融合构建真核表达载体 ,在中国仓鼠卵CHO细胞中表达 ,发现mLPTS基因表达产物位于细胞核仁中 ,为进一步研究该基因的功能及作用途径提供了重要信息。
A novel mouse gene mLPTS was cloned by EST assembling, RT PCR and DNA sequencing. The gene fragment for mLPTS is 1244bp in length, encoding a protein of 332 amino acids. The amino acid sequence of mLPTS has 78% homologue with that of LPTS gene, which is a novel liver cancer related gene identified through positional candidate cloning stratage by our laboratory. The expression of LPTS gene was ubiquitous in normal human tissues, whereas levels appeared to be significantly reduced, or sometime undetectable in HCC cells and neoplastic tissues, and it might be involved in the negative regulation of cell proliferation. The expression of mLPTS gene was found in all mouse tissues analyzed, same with that of LPTS gene in human. There was only one transcript for mLPTS gene in mouse tissues. The phylogenetic tree was constructed through the amino acids sequence analysis and the study of the sequence homologue among different species. Next, mLPTS gene was cloned into green fluorescent protein eukarytic expression vector and then transfected into CHO cell line. The green fluorescent was mostly limited in the nucleolus, showing that the gene products of mLPTS in eukaryocytes were located in the nucleolus
基金
国家高科技"863"计划资助项目 (No .2 0 0 1AA2 2 10 2 1)
国家自然科学基金资助项目 (No .3 0 170 5 2 4)~~
