Nociception activates Elk-1 and Sap 1a following expression of the ORL 1 receptor in Chinese hamster ovary cells

Abstract
NOCICEPTIN stimulation of the ORL1 receptor expressed in Chinese hamster ovary (CHO) cells results in the activation of the extracellular signal regulated kinases ERK1 and ERK2. ERK1/ERK2 activation is inhibited by pertussis toxin, the MEK inhibitor PD 98059 and by transient expression o α-transducin, indicating that ORL1 up-regulation of these kinases occurs as a consequence of the release of the G-protei n βγ complex following the activation of pertussis-toxin sensitive Gαi-family G-proteins. Using specific reporter genes we demonstrate that the transcription factors Elk-1 and Sap1a are activated in a pertussis toxin-sensitive manner as a consequence of ORL1 upregulation of ERK1/ERK2 to induce changes in gene expression. The activation of these transcription factors is also inhibited following treatment with PD 98059 and following coexpression of α-transducin.