Mechanism of Action of Atrial Natriuretic Peptide (ANP)

为了了解心房钠尿肽（ANP）的分子作用机制，介导ANP生理作用的受体已被分离、表征、分类为亚型，并在细胞水平上可视化。还确定了C型ANP受体的基因结构。1)纯化和性质：通过亲和层析从牛肺质膜中纯化C型ANP受体，并显示其是由两个70-kDa亚基组成的二硫键连接的同源二聚体。纯化蛋白的胰蛋白酶片段的氨基酸序列进行了测定。2)使用无细胞翻译系统检查C型ANP受体的生物合成过程;糖肽酶消化揭示成熟受体具有每70-kDa亚基三个N -连接寡糖。受体的配体结合活性不受去糖基化的影响。3)免疫组织化学定位：在肾和肺中，受体定位于PO 关于我们 肾小球的树突细胞和上皮细胞。肾小球定位很好地解释了ANP对肾小球滤过率的刺激作用。4)作用机制：用特异性抗受体抗血清和辐射灭活法分析了ANP对颗粒鸟苷酸环化酶的激活作用，并提出了一种新的解离激活机制。5)AN受体亚型的组织特异性分布通过对各种靶组织上的受体的生物化学、免疫化学和药理学表征来揭示。令人惊讶的是，使用培养的血管细胞进行的类似分析揭示，当在体外培养时，动脉细胞开始表达不同的亚型，并且这种有趣的现象被称为“亚型转换”。6)A型心钠素受体的亚单位结构：单链受体亚型，称为A型受体，在牛肾上腺肾小球细胞中以四聚体存在。7)测定了牛C型心钠素受体qe的结构，并与大鼠A型受体qe的结构进行了比较。C型受体基因异常长，跨度超过85 kb。有趣的是，基因组结构（外显子-内含子组织）模仿受体的结构域结构，内含子定位在A和C受体基因中非常相似。少

To understand the molecular mechanism of action of atrial natriuretic peptide (ANP), the receptors mediating the physiological actions of ANP have been isolated, characterized, classified into subtypes, and visualized at the cellular level. The gene structure of the type C ANP receptor was also determined. 1) Purification and Properties : type C ANP receptor was purified from bovine lung plasma membranes by affinity chromatography and shown to be a disulfide-linked homodimer consisting of two 70-kDa subunits. Amino acid sequences of tryptic fragments of the purified protein were determined. 2) Biosynthetic process of the type C ANP receptor was examined using a cell-free translation system ; glycopeptidase digestion revealed that the mature receptor has three N -linked oligosaccharides per 70-kDa subunit. The ligand-binding activity of the receptor was not affected by the deglycosylation. 3) Immunohistochemical localization : in the kidney and lung, the receptor was localized to the po … More docytes of the glomeruli and the epithelial cells, respectively. The glomerular localization explains well the stimulatory effect of ANP on glomerular filtration rate. 4) Mechanism of action : activation by ANP of particulate guanylate cyclase was analyzed by using a specific antireceptor antiserum and by radiation inactivation, and a new dissociative activation mechanism has been proposed. 5) Tissue-specific distribution of AN receptor subtypes was revealed by biochemical, immunochemical, and phrmacological characterization of the receptors on various target tissues. Surprisingly, similar analysis using cultured vascular cells revealed that arterial cells begin to express different subtypes when cultured in vitro and this interesting phenomenon was termed "subtype switching". 6) Subunit structure of the type A ANP receptor : the single chain receptor subtype, termed type A receptor, was shown to be present as a tetramer in the bovine adreal zona glomerulosa cells. 7) The structure of the bovine type C ANP receptor qe was determined and compared with that of the rat type A receptor. The type C receptor gene was unusually long, spanning more than 85 kb. Interesting features are that the genomic structure (exon-intron organization) mimics the domain structure of the receptor and intron positioning is very similar bype A and C receptor genes. Less