Fain J N, Wallace M A, Wojcikiewicz R J
Department of Biochemistry, College of Medicine, University of Tennesse, Memphis 38163.
FASEB J. 1988 Jul;2(10):2569-74. doi: 10.1096/fasebj.2.10.2838362.
Guanine nucleotide-binding regulatory proteins similar to Gs and Gi may be involved in the activation of phospholipases C and A2 by hormones and other ligands. The binding of hormones to receptors that activate phospholipase C is decreased by guanine nucleotides and these hormones also stimulate a high-affinity GTPase activity in cell membranes. Effects of hormones on phospholipase C activity in cell-free preparations are dependent on the presence of guanine nucleotides. In addition, fluoride and nonhydrolyzable GTP analogs activate phospholipases in a manner that can be blocked by GDP beta S. The putative guanine nucleotide-binding regulatory protein that appears to be involved in activation of phospholipase C is sensitive to pertussis toxin in some cells but not in others.
类似于Gs和Gi的鸟嘌呤核苷酸结合调节蛋白可能参与激素和其他配体对磷脂酶C和A2的激活过程。鸟嘌呤核苷酸可降低激素与激活磷脂酶C的受体的结合，并且这些激素还能刺激细胞膜中高亲和力的GTP酶活性。激素对无细胞制剂中磷脂酶C活性的影响取决于鸟嘌呤核苷酸的存在。此外，氟化物和不可水解的GTP类似物以一种可被GDP-β-S阻断的方式激活磷脂酶。在某些细胞中，似乎参与磷脂酶C激活的假定鸟嘌呤核苷酸结合调节蛋白对百日咳毒素敏感，而在其他细胞中则不敏感。
