The amyloid precursor protein fragment his 657-lys 676 inhibits noradrenaline- and enkephaline-induced suppression of voltage sensitive calcium currents in ng108-15 hybrid cells

Abstract We have investigated the effects of the C-terminal amyloid precursor protein fragment His 657-Lys 676 upon calcium currents in NG108-15 neuroblastoma × glioma hybrid cells. The amyloid precursor protein fragment His 657-Lys 676 (1–10μM) did not affect calcium currents per se , but clearly blocked the calcium current suppression mediated by both adrenergic α 2B - and opioid δ receptors in a concentration-dependent manner. The reverse amyloid precursor protein fragment Lys 676-His 657 and the shorter amyloid precursor protein fragment Gly 659-Lys 676 did not affect calcium current suppression by adrenergic α 2B and opioid δ receptors. The similar interaction of C-terminal amyloid precursor protein with adrenergic α 2B - and opioid δ receptors suggest that the effect occurs downstream of the receptor, possibly via the GTP binding protein G o .