Light-Dependent Translocation of Arrestin in Rod Photoreceptors is Signaled through a Phospholipase C Cascade and Requires ATP

Light adaptation of rod photoreceptors induces translocation of arrestin from inner segments (IS) to outer segments (OS). Our study suggests that components of the G-protein linked phosphoinositide pathway play a role in signaling the initiating events of arrestin translocation. We show that arrestin translocation can be stimulated by activators of phospholipase C (PLC) and protein kinase C (PKC) in the absence of light. Conversely, arrestin translocation to the OS is significantly slowed by inhibitors of PLC and PKC.In the second part of this study, we investigated the mechanism by which arrestin translocates in response to light. Other investigators have suggested that arrestin translocat…