June 2013
Volume 54, Issue 15
Free
ARVO Annual Meeting Abstract  |   June 2013
Interactions between Dopamine Receptor D4 and Visual Arrestins
Author Affiliations & Notes
  • Janise Deming
    Mary D. Allen Lab for Vision Research, Doheny Eye Institute, Los Angeles, CA
    Ophthalmology & Cell & Neurobiology, Keck School of Medicine of Univ. Southern Calif., Los Angeles, CA
  • Kayleen Lim
    Mary D. Allen Lab for Vision Research, Doheny Eye Institute, Los Angeles, CA
    Ophthalmology & Cell & Neurobiology, Keck School of Medicine of Univ. Southern Calif., Los Angeles, CA
  • Bruce Brown
    Mary D. Allen Lab for Vision Research, Doheny Eye Institute, Los Angeles, CA
    Ophthalmology & Cell & Neurobiology, Keck School of Medicine of Univ. Southern Calif., Los Angeles, CA
  • Joseph Pak
    Mary D. Allen Lab for Vision Research, Doheny Eye Institute, Los Angeles, CA
    Ophthalmology & Cell & Neurobiology, Keck School of Medicine of Univ. Southern Calif., Los Angeles, CA
  • Kathleen Van Craenenbroeck
    Physiology, University of Gent, Gent, Belgium
  • Cheryl Craft
    Mary D. Allen Lab for Vision Research, Doheny Eye Institute, Los Angeles, CA
    Ophthalmology & Cell & Neurobiology, Keck School of Medicine of Univ. Southern Calif., Los Angeles, CA
  • Footnotes
    Commercial Relationships Janise Deming, None; Kayleen Lim, None; Bruce Brown, None; Joseph Pak, None; Kathleen Van Craenenbroeck, None; Cheryl Craft, None
  • Footnotes
    Support None
Investigative Ophthalmology & Visual Science June 2013, Vol.54, 2452. doi:
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      Janise Deming, Kayleen Lim, Bruce Brown, Joseph Pak, Kathleen Van Craenenbroeck, Cheryl Craft; Interactions between Dopamine Receptor D4 and Visual Arrestins. Invest. Ophthalmol. Vis. Sci. 2013;54(15):2452.

      Download citation file:


      © ARVO (1962-2015); The Authors (2016-present)

      ×
  • Supplements
Abstract

Purpose: Dopamine (DA) and its G-protein coupled receptors (GPCR) contribute to normal photopic vision, including light adaptation and contrast sensitivity, but the specific cellular pathways by which they contribute are unclear. Similar defective visual phenotypes are observed when either the DA receptor D4 (DRD4) or cone arrestin (ARR4) is not expressed. The purpose of this study was to determine the contribution of ARR4 in the desensitization of DRD4 in vitro and in photopic vision.

Methods: Immunohistochemistry (IHC) was performed using specific antibodies on frozen sections of mouse retinas or fixed transfected cells. C57Bl/6J mice were used, along with Drd4-/- and the four ARR knockout mice (J. Chen, USC; R. Lefkowitz, Duke) as negative controls. Co-immunoprecipitation (co-IP) followed by immunoblot analysis was used for protein-protein interactions. DRD4 desensitization was measured using in vitro internalization experiments with tagged plasmid constructs of human DRD4 and four ARRs in transfected HEK 293T cells incubated with or without 10 µM DA.

Results: IHC of control compared to Drd4-/- retinas revealed the co-expression of DRD4 and ARR4 in cone pedicles, with higher DRD4 expression in dark vs. light adapted mice. Both βARR1 and βARR2 were also expressed in photoreceptors. DRD4 interaction with βARR2 is DA independent, but our co-IP data demonstrated a DA dependent interaction between DRD4 and ARR4 but not ARR1. In vitro studies showed DRD4 internalization only when a βARR and a visual ARR were co-transfected with DRD4. Internalization was highest with βARR2 and ARR4, but other combinations revealed limited internalization; however, none was detectable with two βARRs or two visual ARRs.

Conclusions: DRD4 and ARR4 are required for normal photopic vision and are co-expressed with ARR1 and βARRs in cone photoreceptors, particularly in the pre-synaptic terminals. Our studies demonstrate that for complete desensitization of the DRD4, indicated by internalization after DA stimulation, at least one visual ARR must be co-expressed with a βARR. To our knowledge, no GPCR has previously been shown to require the expression of two different ARRs for desensitization. Our in vitro experiments indicate that not only is the interaction of DRD4, a visual arrestin, and a βARR possible in the cone photoreceptors, but their interaction may play an essential role in maintaining normal high acuity vision.

Keywords: 648 photoreceptors • 502 dopamine • 675 receptors: pharmacology/physiology  
×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×