July 1986
Volume 27, Issue 7
Free
Articles  |   July 1986
Retinoid-binding proteins in cone-dominant retinas.
Investigative Ophthalmology & Visual Science July 1986, Vol.27, 1015-1026. doi:
  • Views
  • PDF
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      D H Anderson, J Neitz, J C Saari, D D Kaska, J Fenwick, G H Jacobs, S K Fisher; Retinoid-binding proteins in cone-dominant retinas.. Invest. Ophthalmol. Vis. Sci. 1986;27(7):1015-1026.

      Download citation file:


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

      ×
  • Supplements
Abstract

We identified and localized interphotoreceptor (or interstitial) retinoid-binding protein (IRBP) and cellular retinaldehyde-binding protein (CRALBP) in the cone-dominant retinas of diurnal squirrels. Western blots were prepared from sodium dodecyl sulfate polyacrylamide gels (SDS-PAGE) from whole retina, and from retina proximal and distal to the photoreceptor nuclei. Blots were incubated with purified rabbit IgG's specific for the bovine retinal antigens, and the labeled components were visualized using immunoperoxidase techniques. Anti-bovine IRBP and anti-bovine CRALBP recognized single components on gels of retinal supernatants that corresponded to the electrophoretic migration of the bovine antigens. The component recognized by anti-bovine IRBP on blots of outer retinal proteins (Mr 146,000) was absent on blots of inner retinal proteins. Twelve and 24 hr after intravitreal injection of 3H-L-fucose, electropherograms showed one major peak of radioactivity that coincided with the component recognized by anti-bovine IRBP. By immunoelectron microscopy, anti-bovine CRALBP labeling was restricted to the cytoplasm of both RPE and Muller cells, with light labeling of nuclear euchromatin in both cell types. In contrast, anti-bovine IRBP recognized antigenic sites primarily in the interphotoreceptor space (IPS). Intracellular labeling was limited to occasional granules in the photoreceptor myoids and the apical RPE cytoplasm. Extracellular labeling with anti-bovine IRBP was strongly associated with patches or small clumps of amorphous, electron opaque material distributed throughout the IPS. This material was particularly prominent near the cone outer segment plasma membranes, and was tentatively identified as the residual interphotoreceptor matrix that remained after exposure to the solvents used during tissue processing. In general, the results are consistent with those obtained in rod-dominant species. In addition, they imply that cones as well as rods are responsible for IRBP synthesis in the ground squirrel.

×
×

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.

×