Cloning of protein tyrosine phosphatase gene family and its gene expression

1.酪氨酸磷酸酶(LRP)基因的克隆利用聚合酶链式反应(PCR)从人肾cDNA文库中克隆了人LRP基因。结论：1.人LRP由793个氨基酸组成，含有跨膜区和两个磷酸酶催化结构域，提示它是一种受体型磷酸酶。人LRP基因的克隆以人LRP基因为探针，对人基因组文库进行筛选，得到多个阳性克隆。进一步分析表明，这些克隆没有覆盖cDNA5‘端。我们正在继续对含有LRP cDNA 5‘端的克隆进行筛选。LRPBy RT-PCR方法，克隆了大鼠LRP的部分基因。以此为探针，用Northern方法分析LRP基因的表达。LRP基因在脑、肺、肝、肾、脾、胃、小肠、大肠、骨骼肌、心脏和胰腺中均有表达。LRP基因在脑、肝、肾和骨骼肌中的表达不受禁食、再喂食、链脲佐菌素或地塞米松诱导的高血糖的影响。这些数据表明，LRP的表达可能与高血糖无关。

1. Cloning of a tyrosine phosphatase(Leukocyte common antigen-related phosphatase : LRP) cDNAHuman LRP cDNA were cloned from a human kidney cDNA library by PCR. Human LRP consisted from 793 amino acids, and it contains transmembrane region and two phosphatase catalytic domains, which suggest it is a receptor type phosphatase.2. Cloning of human LRP geneUsing human LRP cDNA as a probe, we screened human genomic library, and obtained several positive clones. Further analysis revealed that these clones did not cover the 5'end of cDNA. We are continuing the screening of the clones contains the 5'end of the LRP cDNA.3. Gene expression of LRPBy RT-PCR method, we cloned partial cDNA of rat LRP. Using it as a probe, LRP gene expression are analyzed by Northern method. LRP gene expression are observed in brain, lung, liver, kidney, spleen, stomach, small and large intestine, skeletal muscle, heart, and pancreas. LRP gene expression in brain, liver, kidney, and skeletal muscle, are unchanged by fasting, refeeding, strepto-zotocin- or dexamethasone-induced hyperglycemia. These data suggest that expression of LRP may not correlate with hyperglycemia.