The GTP‐Binding Proteins, Go and Gi2, of Neural Cloned Cells and Their Changes During Differentiation

Abstract
The levels of the α‐subunits of two GTP‐binding proteins, Go and Gi2, were determined in neural and non‐neural cloned cells by immunoassays. Goα was detected in all neural cells and some of nonneural cells, but not in HL‐60 leukemic cells and PYS‐2 teratocarcinoma‐derived cells. The level of Goα was highest in the PC12 pheochroihocytoma cells. Gi2α was present in all types of cells tested, arid its level was highest in the HL‐60 cells and relatively high in glioma ells. Treatment of PC 12 cells and neuroblastoma X glioma hybrid NG108‐15 cells with nerve growth factor and forskolin, respectively, caused the extension of neuronal‐like processes and increase in the level of Goα by 60‐80%, but small changes in the levels of Gi2α.