The α 2 B adrenergic receptor of undifferentiated neuroblastoma × glioma hybrid NG108-15 cells, interacts directly with the guanine nucleotide binding protein, G i2

Abstract

In membranes of undifferentiated neuroblastoma × glioma hybrid cell line NG108-15, the apparent specific binding of [ 3H]yohimbine measured in the presence of 1 μM noradrenaline, was increased substantially by the presence of the poorly hydrolysed analogue of QTP, guanylyl-imidodiphosphate (Gpp[NH]p) or by preincubation of membranes with antibodies against the C-terminal decapeptide of the α subunit of the G-protein G i2. Such an effect was not produced by antibodies against the equivalent region of G oα G i3α or G sα or from non-immune serum. By contrast, total specific binding of [ 3H]yohimbine was not modified by co-incubation with Gpp[NH]p or by preincubation with the antibodies from any of the anti-G protein antisera. These results demonstrate a direct interaction of the α 2B adrenergic receptor of NG108-15 cells with G i2.