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.
Keywords: CNG channel, Grb14, Insulin receptor, PTP1B, Rhodopsin, Rod outer
segments, Tyrosine phosphorylation.
