Interaction of GTP‐binding proteins with calmodulin

FEBS Letters

Ogasawara, Nobuaki¹  Kitajima, Satoko²  Sano, Mamoru²  Asano, Tomiko¹ 

[1] Department of Biochemistry, Institute for Developmental Research, Aichi Prefectural Colony, Kasugai, Aichi 480-03, Japan;Department of Morphology, Institute for Developmental Research, Aichi Prefectural Colony, Kasugai, Aichi 480-03, Japan

关键词: GTP-binding protein;    Calmodulin;    Cyclic nucleotide phosphodiesterase;    Protein interaction;   

DOI  :  10.1016/0014-5793(86)80729-3

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Two GTP-binding proteins (G_i and G_o), which were the substrates for islet-activating protein, pertussis toxin, were purified from bovine cerebral cortical membranes. Both G_i and G_o completely inhibited calmodulin-stimulated cyclic nucleotide phosphodiesterase activity. The same concentrations of these proteins, however, had no appreciable effect on the basal phosphodiesterase activity. The isolated G_iα and βγ subunits of GTP-binding proteins were potent inhibitors of the calmodulin-stimulated phosphodiesterase activity, but G_oα was very weak. Therefore, the βγ subunits were likely to be the major active molecules in the brain membranes. GTP-binding proteins were shown to bind directly to calmodulin in a Ca²⁺-dependent manner by a gel permeation binding experiment.

【 授权许可】

Unknown