Rhodopsin C terminus, the site of mutations causing retinal disease, regulates trafficking by binding to ADP-ribosylation factor 4 (ARF4)

Proc Natl Acad Sci U S A. 2005 Mar 1;102(9):3301-6. doi: 10.1073/pnas.0500095102. Epub 2005 Feb 22.

Abstract

The maintenance of photoreceptor cell polarity is compromised by the rhodopsin mutations causing the human disease autosomal dominant retinitis pigmentosa. The severe form mutations occur in the C-terminal sorting signal of rhodopsin, VXPX-COOH. Here, we report that this sorting motif binds specifically to the small GTPase ARF4, a member of the ARF family of membrane budding and protein sorting regulators. The effects of blocking ARF4 action were functionally equivalent to the effects of blocking the rhodopsin C-terminal sorting signal. ARF4 was essential for the generation of post-Golgi carriers targeted to the rod outer segments of retinal photoreceptors. Thus, the severe retinitis pigmentosa alleles that affect the rhodopsin sorting signal interfere with interactions between ARF4 and rhodopsin, leading to aberrant trafficking and initiation of retinal degeneration.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • ADP-Ribosylation Factors / metabolism*
  • Amino Acid Sequence
  • Animals
  • Blotting, Western
  • Electrophoresis, Polyacrylamide Gel
  • Golgi Apparatus / metabolism
  • Microscopy, Confocal
  • Mutation*
  • Protein Binding
  • Protein Transport
  • Ranidae
  • Reactive Oxygen Species
  • Rhodopsin / chemistry
  • Rhodopsin / genetics
  • Rhodopsin / metabolism
  • Rhodopsin / physiology*

Substances

  • Reactive Oxygen Species
  • Rhodopsin
  • ADP-Ribosylation Factors