The translocation of signaling molecules in dark adapting mammalian rod photoreceptor cells is dependent on the cytoskeleton
Article first published online: 11 JUL 2008
Copyright © 2008 Wiley-Liss, Inc.
Cell Motility and the Cytoskeleton
Volume 65, Issue 10, pages 785–800, October 2008
How to Cite
Reidel, B., Goldmann, T., Giessl, A. and Wolfrum, U. (2008), The translocation of signaling molecules in dark adapting mammalian rod photoreceptor cells is dependent on the cytoskeleton. Cell Motil. Cytoskeleton, 65: 785–800. doi: 10.1002/cm.20300
- Issue published online: 4 SEP 2008
- Article first published online: 11 JUL 2008
- Manuscript Accepted: 2 JUN 2008
- Manuscript Received: 14 MAR 2008
- Deutsche Forschungsgemeinschaft (DFG)
- Pro Retina Deutschland e.V.
- FAUN-Stiftung, Nürnberg, Germany
- light adaptation;
- molecular movements
In vertebrate rod photoreceptor cells, arrestin and the visual G-protein transducin move between the inner segment and outer segment in response to changes in light. This stimulus dependent translocation of signalling molecules is assumed to participate in long term light adaptation of photoreceptors. So far the cellular basis for the transport mechanisms underlying these intracellular movements remains largely elusive. Here we investigated the dependency of these movements on actin filaments and the microtubule cytoskeleton of photoreceptor cells. Co-cultures of mouse retina and retinal pigment epithelium were incubated with drugs stabilizing and destabilizing the cytoskeleton. The actin and microtubule cytoskeleton and the light dependent distribution of signaling molecules were subsequently analyzed by light and electron microscopy. The application of cytoskeletal drugs differentially affected the cytoskeleton in photoreceptor compartments. During dark adaptation the depolymerization of microtubules as well as actin filaments disrupted the translocation of arrestin and transducin in rod photoreceptor cells. During light adaptation only the delivery of arrestin within the outer segment was impaired after destabilization of microtubules. Movements of transducin and arrestin required intact cytoskeletal elements in dark adapting cells. However, diffusion might be sufficient for the fast molecular movements observed as cells adapt to light. These findings indicate that different molecular translocation mechanisms are responsible for the dark and light associated translocations of arrestin and transducin in rod photoreceptor cells. Cell Motil. Cytoskeleton 65: 785–800, 2008. © 2008 Wiley-Liss, Inc.