The cellular prion protein prevents copper-induced inhibition of P2X 4 receptors

Abstract

Although the physiological function of the cellular prion protein (PrP C) remains unknown, several evidences support the notion of its role in copper homeostasis. PrP C binds Cu 2+ through a domain composed by four to five repeats of eight amino acids. Previously, we have shown that the perfusion of this domain prevents and reverses the inhibition by Cu 2+ of the adenosine triphosphate (ATP)-evoked currents in the P2X 4 receptor subtype, highlighting a modulatory role for PrP C in synaptic transmission through regulation of Cu 2+ levels. Here, we study the effect of full-length PrP C in Cu 2+ inhibition of P2X 4 receptor when both are coexpressed. PrP C expression does not significantly change the ATP concentration-response curve in oocytes expressing P2X 4 receptors. However, the presence of PrP C reduces the inhibition by Cu 2+ of the ATP-elicited currents in these oocytes, confirming our previous observations with the Cu 2+ binding domain. Thus, our observations suggest a role for PrP C in modulating synaptic activity through binding of extracellular Cu 2+. Copyright © 2011 Ramn A. Lorca et al.