May 2004
Volume 45, Issue 13
Free
ARVO Annual Meeting Abstract  |   May 2004
The interaction between the DEP domain of RGS9 and R9AP determines subcellular localization and stability of the RGS9–Gß5 GTPase activating complex in photoreceptors
Author Affiliations & Notes
  • K.A. Martemyanov
    Ophthalmology,
    Harvard Medical School, Boston, MA
  • G. Keresztes
    Otolaryngology,
    Harvard Medical School, Boston, MA
  • C.M. Krispel
    Psychiatry, University of California, Davis, CA
  • P. Lishko
    Ophthalmology,
    Harvard Medical School, Boston, MA
  • N. Calero
    Psychiatry, University of California, Davis, CA
  • J. Lem
    Ophthalmology, Tufts University School of Medicine, Boston, MA
  • C.–K.J. Chen
    Ophthalmology, University of Utah, Salt Lake City, UT
  • M.E. Burns
    Psychiatry, University of California, Davis, CA
  • S. Heller
    Otolaryngology,
    Harvard Medical School, Boston, MA
  • V.Y. Arshavsky
    Ophthalmology,
    Harvard Medical School, Boston, MA
  • Footnotes
    Commercial Relationships  K.A. Martemyanov, None; G. Keresztes, None; C.M. Krispel, None; P. Lishko, None; N. Calero, None; J. Lem, None; C.J. Chen, None; M.E. Burns, None; S. Heller, None; V.Y. Arshavsky, None.
  • Footnotes
    Support  NIH, AHA
Investigative Ophthalmology & Visual Science May 2004, Vol.45, 2211. doi:
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      K.A. Martemyanov, G. Keresztes, C.M. Krispel, P. Lishko, N. Calero, J. Lem, C.–K.J. Chen, M.E. Burns, S. Heller, V.Y. Arshavsky; The interaction between the DEP domain of RGS9 and R9AP determines subcellular localization and stability of the RGS9–Gß5 GTPase activating complex in photoreceptors . Invest. Ophthalmol. Vis. Sci. 2004;45(13):2211.

      Download citation file:


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

      ×
  • Supplements
Abstract

Abstract: : Purpose: Timely termination of the light response in retinal photoreceptors requires rapid inactivation of the G protein transducin. This is achieved through the stimulation of transducin GTPase activity by the RGS9–Gß5 protein complex. A transmembrane protein R9AP anchors RGS9–Gß5 to photoreceptor disc membranes by interacting with the DEP domain of RGS9. Our goal was to identify the functional consequences of this interaction in vivo. Methods: We generated two genetically modified mice: a transgenic mouse where the RGS9 mutant lacking the DEP domain was expressed in the rods of RGS9 knockout animals (DEP–less) and another mouse where the R9AP gene was knocked out (R9AP KO). The levels of mRNA and proteins were analyzed using Northern and Western blots respectively. The distribution of proteins in the rod photoreceptor compartments was studied using a combination of immunohistochemical methods and the serial tangential sectioning/Western blotting technique. The photoresponses from transgenic rods were recorded using the suction electrode technique. Results: We have found that RGS9 was completely absent from the retinas of R9AP KO mice, whereas the level of RGS9 mRNA was not affected by the R9AP knockout. On the other hand, the RGS9 mutant protein lacking the DEP domain was expressed in the normal amount but was not delivered to rod outer segments. Electrophysiological studies of the mouse photoreceptors revealed that the light responses of both R9AP KO and DEP–less rods were very slow to recover and indistinguishable from those of rods of the RGS9 knockout mice. Conclusions: We conclude that both the stability of RGS9 in the rod cell and its delivery to the rod outer segment is determined by the interaction between the DEP domain of RGS9 and R9AP.

Keywords: photoreceptors • signal transduction • protein structure/function 
×
×

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.

×