Wang Y, Tan S, Hooi S C
Department of Physiology, Faculty of Medicine, National University of Singapore, Singapore.
Dig Dis Sci. 1999 Jan;44(1):25-32. doi: 10.1023/a:1026685613212.
This paper describes the identification and characterization of a novel cDNA encoding a putative protein of 254 amino acids that is highly homologous to triosephosphate isomerase. The cDNA was isolated by subtractive hybridization and was differentially expressed in the remnant rat ileum after massive small bowel resection. The novel triosephosphate isomerase was named rsTPI (resection-induced TPI) and the putative protein encoded RSTPI. The nucleotide and amino acid sequences of rsTPI and RSTPI were about 60% and 62% homologous to Giardia lamblia TPI and TPI, respectively. Active catalytic sites (Lys 13, His 95, and Glu 167) and the peptide motifs, AYEPVWSIGT and GGASLKPEF found in other triosephosphate isomerases were conserved in RSTPI. rsTPI expression was detected in normal ileum and pancreas by reverse transcription-polymerase chain reaction. Expression of rsTPI in remnant rat ileum was detectable by northern blot analysis one week after massive small bowel resection. Expression increased significantly by 2.8-fold between one and two weeks after surgery. High levels were maintained for at least one month after surgery. The up-regulation of triosephosphate isomerase expression in the remnant small intestine after massive resection indicates that it may play an important role in the adaptive process.
本文描述了一种新的cDNA的鉴定和特征，该cDNA编码一种推定的含254个氨基酸的蛋白质，与磷酸丙糖异构酶高度同源。该cDNA通过消减杂交分离得到，在大鼠小肠大部切除术后的残余回肠中差异表达。这种新的磷酸丙糖异构酶被命名为rsTPI（切除诱导的TPI），其编码的推定蛋白质为RSTPI。rsTPI和RSTPI的核苷酸和氨基酸序列分别与蓝氏贾第鞭毛虫TPI和TPI约60%和62%同源。RSTPI中保留了其他磷酸丙糖异构酶中发现的活性催化位点（赖氨酸13、组氨酸95和谷氨酸167）以及肽基序AYEPVWSIGT和GGASLKPEF。通过逆转录-聚合酶链反应在正常回肠和胰腺中检测到rsTPI表达。通过Northern印迹分析在大鼠小肠大部切除术后一周可检测到残余回肠中rsTPI的表达。术后1至2周表达显著增加2.8倍。术后至少一个月维持高水平。小肠大部切除术后残余小肠中磷酸丙糖异构酶表达的上调表明它可能在适应性过程中起重要作用。
