人肾高亲和力钠离子依赖性二羧酸转运蛋白基因的克隆和生物信息学分析

为探讨人高亲和力钠离子依赖性二羧酸转运蛋白 (humanhigh affinitysodium dependentdicar boxylatetransporter,hSDCT2orhNaDC3 )基因在人体内的生理功能及其与疾病的关系 ,借助生物信息学成功地从人肾中克隆了hSDCT2基因 (GenBank接收号 :AY0 72 810 ) .首先将大鼠SDCT2cDNA与人EST数据库进行同源性比较 ,获得具有高度同源性EST片段并用DNAstar软件将它们拼接成EST重叠群 .在重叠群上设计PCR引物从人肾总RNA中用RT PCR扩增出hSDCT2基因并测序 ,然后用软件对其结构特性、组织分布及基因定位进行分析 .序列测定结果显示 ,hSDCT2开放阅读框为180 9bp ,共编码 6 0 2个氨基酸 .蛋白同源性分析表明 ,其氨基酸序列与大鼠及小鼠SDCT2分别有85 %和 87%相同 .二级结构分析显示 ,该蛋白有 12个跨膜螺旋区 .Northern分析显示 ,该基因可在肾、肝、脑、胎盘等多种组织中表达 ,并定位于 2 0号染色体的q12～q13 1

Cloning and Bioinformatics Analysis of High-affinity Sodium-dependent Dicarboxylate Transporter Gene from Human Kidney

To study the physiological function and the relationship of human high affinity sodium dependent dicarboxylate transporter protein (hSDCT2,hNaDC 3) with human diseases, hSDCT 2 cDNA gene was successfully cloned from human kidney by the bioinformatics (GenBank Accession Number: AY072810). Rat SDCT 2 cDNA was compared with human EST database to obtain EST fragments with high homology. These ESTs were assembled into contig by DNAstar software. Based on the contig sequence, PCR primers were designed and hSDCT 2 cDNA was amplified from human kidney total RNA by RT PCR and sequenced. The sequencing results showed that hSDCT 2 cDNA contained 1809 bp open reading frame to encode 602 amino acids. Homology analysis indicated that amino acid sequence of hSDCT2 protein had 85% and 87% identity with rat and mouse SDCT2, respectively. The prediction of secondary structure for hSDCT2 protein showed that the protein contained 12 putative α helix transmembrane domains. Northern bloting analysis suggested that the gene was expressed in human kidney, liver, placenta and brain. hSDCT2 gene was located on chromosome 20q12—13.1 by HTGS and STS/GDB.