Higashida H, Streaty R A, Klee W, Nirenberg M
Proc Natl Acad Sci U S A. 1986 Feb;83(4):942-6. doi: 10.1073/pnas.83.4.942.
The addition of bradykinin to NG108-15 cells results in a transient hyperpolarization followed by prolonged cell depolarization. Injection of inositol 1,4,5-trisphosphate or Ca2+ into the cytoplasm of NG108-15 cells also elicits cell hyperpolarization followed by depolarization. Tetraethylammonium ions inhibit the hyperpolarizing response of cells to bradykinin or inositol 1,4,5-trisphosphate. Thus, the hyperpolarizing phase of the cell response may be due to inositol 1,4,5-trisphosphate-dependent release of stored Ca2+ into the cytoplasm, which activates Ca2+-dependent K+ channels. The depolarizing phase of the cell response to bradykinin is due largely to inhibition of M channels, thereby decreasing the rate of K+ efflux from cells and, to a lesser extent, to activation of Ca2+-dependent ion channels and Ca2+ channels. In contrast, injection of inositol 1,4,5-trisphosphate or Ca2+ into the cytosol did not alter M channel activity. Incubation of NG108-15 cells with pertussis toxin inhibits bradykinin-dependent cell hyperpolarization and depolarization. Bradykinin stimulates low Km GTPase activity and inhibits adenylate cyclase in NG108-15 membrane preparations but not in membranes prepared from cells treated with pertussis toxin. Reconstitution of NG108-15 membranes from cells treated with pertussis toxin with nanomolar concentrations of a mixture of highly purified No and Ni [guanine nucleotide-binding proteins that have no known function (No) or inhibit adenylate cyclase (Ni)] restores bradykinin-dependent activation of GTPase and inhibition of adenylate cyclase. These results show that [bradykinin . receptor] complexes interact with No or Ni and suggest that No and/or Ni mediate the transduction of signals from bradykinin receptors to phospholipase C and adenylate cyclase.
向NG108 - 15细胞中添加缓激肽会导致短暂的超极化，随后是细胞的长时间去极化。向NG108 - 15细胞的细胞质中注射肌醇1,4,5 - 三磷酸或Ca2 +也会引发细胞超极化，随后是去极化。四乙铵离子抑制细胞对缓激肽或肌醇1,4,5 - 三磷酸的超极化反应。因此，细胞反应的超极化阶段可能是由于肌醇1,4,5 - 三磷酸依赖的储存Ca2 +释放到细胞质中，从而激活了Ca2 +依赖性K +通道。细胞对缓激肽反应的去极化阶段主要是由于M通道的抑制，从而降低了K +从细胞外流的速率，并且在较小程度上是由于Ca2 +依赖性离子通道和Ca2 +通道的激活。相比之下，向细胞质中注射肌醇1,4,5 - 三磷酸或Ca2 +不会改变M通道活性。用百日咳毒素孵育NG108 - 15细胞会抑制缓激肽依赖性的细胞超极化和去极化。缓激肽刺激NG108 - 15细胞膜制剂中的低Km GTP酶活性并抑制腺苷酸环化酶，但在用百日咳毒素处理的细胞制备的膜中则不然。用纳摩尔浓度的高度纯化的No和Ni（无已知功能的鸟嘌呤核苷酸结合蛋白（No）或抑制腺苷酸环化酶的蛋白（Ni））的混合物对用百日咳毒素处理的细胞的NG108 - 15膜进行重组，可恢复缓激肽依赖性的GTP酶激活和腺苷酸环化酶抑制。这些结果表明，[缓激肽.受体]复合物与No或Ni相互作用，并表明No和/或Ni介导从缓激肽受体到磷脂酶C和腺苷酸环化酶的信号转导。
