GABAB receptors couple to G proteins Go, G∗ o and G·i1 but not to Gi2

FEBS Letters

Kato, Kanefusa²  Asano, Tomiko²  Morishita, Rika¹ 

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

关键词: GABAB receptor;    GTP-binding protein;    N-Ethylmaleimide;    Reconstitution;   

DOI  :  10.1016/0014-5793(90)80413-D

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

We studied the selectivity of GABA_B receptors for coupling to G proteins by testing the ability of various purified G proteins to increase GABA binding to N-ethylmaleimide (NEM)-treated membranes of bovine brain. The addition of G_o, G^∗ _o or g_i1 to NEM-treated membranes increased GABA binding in a dose-dependent manner. However, the addition of G_i2 did not elicit a marked increase in GABA binding. When α subunits of G proteins were mixed with various brain βγ subunit complexes composed of different γ subunits, and they were added to the NEM-treated membranes, G_i2 with any βγ subunits hardly increased GABA binding. On the other hand, G_o with any βγ subunits caused a marked increase, though G_o with a small γ subunit was more effective than that with a large γ subunit. These data suggest that the selective coupling of the G proteins to GABA_B receptors is determined by the α subunit.

【 授权许可】

Unknown