Inagami T, Guo D F, Kitami Y
Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232-0146, USA.
J Hypertens Suppl. 1994 Dec;12(10):S83-94.
So far, three isoforms of angiotensin II receptors have been identified by complementary DNA cloning, all with seven transmembrane domain structures. AT1A and AT1B are the most common isoforms. They are coupled to phospholipase C through Gq/G11 proteins and to a calcium channel, and negatively coupled to adenyl cyclase. AT2 is only remotely related to the AT1 family. KNOWN STRUCTURAL DETAILS OF ANGIOTENSIN II RECEPTORS: Ligand-binding domains are being defined in the space surrounded by transmembrane helices. Coupling to Gq seems to involve the second cytosolic loop. Receptor proteins undergo transition to a low-affinity form, which is desensitized and internalized. CHROMOSOME LOCATION: In the rat, AT1A, AT1B and AT2 are located on chromosomes 17, 2 and X, respectively. SIGNALING PATHWAY: Studies with receptors are revealing several different pathways of angiotensin signaling that modulate protein tyrosine phopsphorylation.
血管紧张素 II 受体的亚型：到目前为止，通过互补 DNA 克隆已鉴定出三种血管紧张素 II 受体亚型，均具有七个跨膜结构域。AT1A 和 AT1B 是最常见的亚型。它们通过 Gq/G11 蛋白与磷脂酶 C 偶联，并与钙通道偶联，且与腺苷酸环化酶负偶联。AT2 与 AT1 家族仅有远缘关系。血管紧张素 II 受体的已知结构细节：配体结合结构域在跨膜螺旋包围的空间中得以界定。与 Gq 的偶联似乎涉及第二个胞质环。受体蛋白会转变为低亲和力形式，该形式会脱敏并内化。染色体定位：在大鼠中，AT1A、AT1B 和 AT2 分别位于第 17、2 和 X 号染色体上。信号通路：对受体的研究揭示了几种不同的血管紧张素信号通路，这些通路可调节蛋白质酪氨酸磷酸化。
