Role of Ca²⁺ for reduction of ERK1/2 phosphorylation.

Abstract

The NECA-induced reduction of ERK1/2 phosphorylation was blocked by the Ca2+-chelator BAPTA intracellularly released from 30 μM of the cell-penetrating derivative BAPTA-AM (A). Consequently, an intracellular increase of Ca2+ triggered by 100 μM UTP (B) resulted in a reduction of ERK1/2 phosphorylation similar to increasing levels of cAMP (C). Western blots and the Ca2+ trace in B show a representative experiment, the columns represent mean values from n = 7 (A) and 8 (C) independent experiments (* p < 0.001, significantly different from control).</p