Rhodopsin-Regulated Grb14 Trafficking to Rod Outer Segments: Functional Role of Grb14 in Photoreceptors
Pp. 101-108 (8)
Raju V.S. Rajala
Growth factor receptor-bound protein 14 (Grb14) belongs to the Grb7
family. It is an adapter molecule, lacking any intrinsic enzyme activity, but mediates
protein-protein and protein-lipid interactions. In photoreceptors, Grb14 undergoes a
rhodopsin-dependent translocation from the inner segments to the outer segments. In
photoreceptors, Grb14 undergoes a light-dependent tyrosine phosphorylation and
protects the insulin receptor (IR) phosphorylation, which is neuroprotective. Outersegment-
localized Grb14 also modulates the activity of the cyclic nucleotide gated
(CNG) chancel. Thus, Grb14 plays a key role in receiving signals from rhodopsin, and
translocating to outer segments, where it regulates IR and CNG channel activities. The
present study supports the idea that rhodopsin regulates non-canonical signaling
pathways in photoreceptor cells.
CNG channel, Grb14, Insulin receptor, PTP1B, Rhodopsin, Rod outer
segments, Tyrosine phosphorylation.
Departments of Ophthalmology, Physiology, and Cell Biology, University of Oklahoma Health Sciences Center, and Dean A. McGee Eye Institute, Oklahoma City, Oklahoma 73104, USA.