On-going Research
Our current efforts focus on the role of two visual arrestins (Arr1 and Arr2) in retinal degeneration and in orchestrating the trafficking of Rh1 rhodopsin. Arr1 has been implicated in the light-dependent endocytosis of Rh1 while Arr2 is essential for the fast deactivation of the visual response. To explore the trafficking of arrestins in live photoreceptors, we have generated transgenic flies expressing GFP-tagged Arr1 or Arr2. We show that only Arr1-GFP displays the light-dependent internalization in pupal, but not adult photoreceptors.
Similarly, we have explored the light-dependent endocytic trafficking of Rh1 rhodopsin. We employ transgenic flies expressing mCherry tagged Rh1 and have established the role of Arr1 in orchestrating the internalization of Rh1 in vivo. Rh1 can be activated by different wavelengths of light leading to internalization. We would like to use the endocytosis of Rh1 as a model for insights into trafficking of G-protein coupled receptors (GPCRs) in the native cellular environment. Following endocytosis, internalized GPCRs can be subjected to either recycling for returning back to the membrane or degradation. We will also investigate how the fate of internalized Rh1 is regulated. We hope insights we gain in Drosophila will broaden our understanding into the trafficking of GPCRs in vivo.