Molecular Biological Studies on new regulatory factors in the control of blood pressure and body fluid with reference to the pathogenesis of hypertension

D-氨基酸氧化酶(EC1.4.3.3，DAO)是一种以FAD为辅基的黄素酶，催化多种氨基酸的氧化脱氨反应。据报道，该酶定位于细胞内，DAO被认为是过氧化物体的特征标志酶。人类基因组包含一个DAO基因拷贝，由11个外显子组成，跨度为20kb。通过筛选一组中国仓鼠和人体细胞杂交种，将人DAO基因座定位在12号染色体上，并用独特的序列引物进行了PCR分析。在第一内含子中存在两个交替的嘧啶和嘌呤核苷酸序列，(CA)20和(CA)17。为了寻找人类DAO基因CA重复微卫星DNA周围序列的异质性，分析了21个独立的人类基因组DNA，包括高加索人、黑人和东方人群体，发现人类DAO基因是一个丰富的多态性标记来源。有TH…肾素结合蛋白(Renin-Binding Protein，RnBP)是一种与肾素结合的蛋白质，形成一种称为高分子量肾素的蛋白质复合体。为探讨其生理功能，采用Northern印迹杂交法检测了RnBP在大鼠主动脉中的基因表达。除肾脏、肾上腺、脑和卵巢外，RnBP基因在大鼠主动脉中也有表达。猪主动脉来源的血管内皮细胞RnBP基因表达水平较高，为肾脏的40%。为了研究猪肾素基因表达与RnBP基因表达的关系，通过对猪肾mRNA进行RT-PCR分析，获得了猪肾素基因片段，并测定了猪肾素基因的核苷酸序列。最后，对内皮细胞中猪肾素基因的RT-PCR分析表明，肾素基因也在同一内皮细胞中表达。血管紧张素Ⅱ和8-溴环腺苷可上调培养内皮细胞的RnBP基因表达。因此，RNBP可能作为血管肾素血管紧张素系统的一员，参与血管内皮细胞的血压调节。较少

D-Amino acid oxidase (EC1.4.3.3, DAO) is a flavoenzyme with FAD as its prosthetic group that catalyzes the oxidative deamination of a wide range of Damino acids. This enzyme was reported to be intracellularly localized in peroxisomes and DAO is regarded as a characteristic marker enzyme of the peroxisomes. The human genome contains a single copy of DAO gene, comprising 11 exons and spanning 20kb. The human DAO locus was assigned to chromosome 12 by screening a panel of Chinese hamster and human somatic cell hybrids with unique sequence primers for PCR analysis. Two sequences of alternating pyrimidine and purine nucleotides, (CA) 20 and (CA) 17, are present in the first intron. In order to search for heterogeneity in the sequences around the CA repeat microsatellite DNA in the human DAO gene, 21 independent human genomic DNAs, comprising Caucasian, Black and Oriental populations were analyzed, and the human DAO gene was found to be an abundant source of polymorphic markers. There are th … More ree other potential sequences for genetic polymorphism in the first intron, namely pentanucleotide ATTTT and 2 poly T tract.Renin-binding protein (RnBP) is a protein that binds to renin, forming a protein complex called high molecular weight renin. In search of its physiological function, gene expression of RnBP in rat aorta were examined by Northern blot hybridization. RnBP gene expression was observed in rat aorta, in addition to kidney, adrenal gland, brain and ovary. The arterial endothelial cells derived from porcine aorta exhibited high level of RnBP gene expression, 40% of the level observed in the kidney. In order to study renin gene expression in relation to that of RnBP,porcine renin cDNA fragment was isolated by RT-PCR analysis of porcine kidney mRNA,followed by determination of the nucleotide sequence for porcine renin. Finally, the RT-PCR analysis of porcine renin mRNA in endothelial cells has shown that renin gene is also expressed in the same endothelium. RnBP gene expression was shown to be up-regulated by Angiotens in II and 8-bromo cAMP in cultured endothelial cells. RnBP,therefore, may participate in blood pressure regulation at vascular endothelium as a member of vascular reninangiotensin system. Less