Structural analysis of angiotensin IV receptor (AT₄) from selected bovine tissues

作     者：Zhang, JH Hanesworth, JM Sardinia, MF Alt, JA Wright, JW Harding, JW 

作者机构：Washington State Univ Dept Vet & Comparat Anat Pharmacol & Physiol Pullman WA 99164 USA 

出 版 物：《JOURNAL OF PHARMACOLOGY AND EXPERIMENTAL THERAPEUTICS》 (药理学与实验治疗学杂志)

年 卷 期：1999年第289卷第2期

页      面：1075-1083页

核心收录：

学科分类：1007[医学-药学(可授医学、理学学位)] 10[医学] 

主　　题：血管紧张素Ⅱ/类似物和衍生物 血管紧张素Ⅱ/化学 色谱法 高压液相 电泳 聚丙烯酰氨凝胶 糖基化 配体 膜 分子量 器官特异性 受体 血管紧张素/化学 动物 牛 

摘      要：The angiotensin IV receptor (AT(4)) receptor is widely distributed in both species and tissues. This broad distribution appears to be reflected in an equally diverse repertoire of physiological actions that are mediated through AT(4) receptors. This breadth of location and function of AT(4) receptors encourages speculation that multiple AT(4) isoforms might exist. In this study, we compared the structural properties of bovine AT(4) receptors from adrenals, kidney, heart, thymus, bladder, aorta, and hippocampus. These comparisons were made using polyacrylamide gel electrophoresis or HPLC analysis of AT(4) receptors that had been covalently radiolabeled with the AT(4)-specific photoprobe I-125-benzoyl phenylalamine-angiotensin IV. Except for the hippocampal AT(4) receptor, the binding subunit in all tissues had a molecular mass of approximately 165 kDa and associated with additional subunits via disulfide linkages. The hippocampal receptor was significantly smaller (150 kDa) and did not appear to possess other disulfide-linked subunits. The receptor was highly glycosylated in all tissues examined. Peptide mapping following cleavage of I-125-labeled receptor with endopeptidase C or cyanogen bromide resulted in complex cleavage patterns. Together these mapping studies demonstrated the uniqueness of the hippocampal receptor and further suggested that other AT(4) isoforms may exist and be variably distributed among bovine tissues. In agreement with the peptide mapping studies, differences in the binding pattern of several AngIV analogs were observed among the various tissues.