The cGMP-gated channel and related glutamic acid-rich proteins interact with peripherin-2 at the rim region of rod photoreceptor disc membranes

J Biol Chem. 2001 Dec 21;276(51):48009-16. doi: 10.1074/jbc.M108941200. Epub 2001 Oct 18.

Abstract

The rod cGMP-gated channel is localized in the plasma membrane of rod photoreceptor outer segments, where it plays a central role in phototransduction. It consists of alpha- and beta-subunits that assemble into a heterotetrameric protein. Each subunit contains structural features characteristic of nucleotide-gated channels, including a cGMP-binding domain, multiple membrane-spanning segments, and a pore region. In addition, the beta-subunit has a large glutamic acid- and proline-rich region called GARP that is also expressed as two soluble protein variants. Using monoclonal antibodies in conjunction with immunoprecipitation, cross-linking, and electrophoretic techniques, we show that the cGMP-gated channel associates with the Na/Ca-K exchanger in the rod outer segment plasma membrane. This complex and soluble GARP proteins also interact with peripherin-2 oligomers in the rim region of outer segment disc membranes. These results suggest that channel/peripherin protein interactions mediated by the GARP part of the channel beta-subunit play a role in connecting the rim region of discs to the plasma membrane and in anchoring the channel.exchanger complex in the rod outer segment plasma membrane.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Cattle
  • Cyclic GMP / physiology*
  • Cyclic Nucleotide-Gated Cation Channels
  • Electrophoresis, Polyacrylamide Gel
  • Eye Proteins / chemistry
  • Eye Proteins / metabolism*
  • Glutamic Acid / analysis*
  • Intermediate Filament Proteins / metabolism*
  • Ion Channel Gating*
  • Ion Channels / chemistry
  • Ion Channels / metabolism*
  • Membrane Glycoproteins*
  • Membrane Proteins / chemistry
  • Membrane Proteins / metabolism*
  • Molecular Sequence Data
  • Nerve Tissue Proteins / metabolism*
  • Peripherins
  • Precipitin Tests
  • Protein Binding
  • Rod Cell Outer Segment / metabolism*

Substances

  • Cyclic Nucleotide-Gated Cation Channels
  • Eye Proteins
  • Intermediate Filament Proteins
  • Ion Channels
  • Membrane Glycoproteins
  • Membrane Proteins
  • Nerve Tissue Proteins
  • Peripherins
  • Glutamic Acid
  • Cyclic GMP