Multiple sites of interaction between the intracellular domains of an inwardly rectifying potassium channel, Kir6.2

FEBS Lett. 2001 Nov 9;508(1):85-9. doi: 10.1016/s0014-5793(01)03023-x.

Abstract

The amino-terminal and carboxy-terminal domains of inwardly rectifying potassium channel (Kir) subunits are both intracellular. A direct physical interaction between these two domains is involved in the response of Kir channels to regulatory factors such as G-proteins, nucleotides and intracellular pH. We have previously mapped the region within the N-terminal domain of Kir6.2 that interacts with the C-terminus. In this study we use a similar in vitro protein-protein interaction assay to map the regions within the C-terminus which interact with the N-terminus. We find that multiple interaction domains exist within the C-terminus: CID1 (amino acids (aa) 279-323), CID2 (aa 214-222) and CID3 (aa 170-204). These domains correlate with regions previously identified as making important contributions to Kir channel assembly and function. The highly conserved nature of the C-terminus suggests that a similar association with the N-terminus may be a feature common to all members of the Kir family of potassium channels, and that it may be involved in gating of Kir channels by intracellular ligands.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Molecular Sequence Data
  • Potassium Channels, Inwardly Rectifying / chemistry
  • Potassium Channels, Inwardly Rectifying / genetics
  • Potassium Channels, Inwardly Rectifying / metabolism*
  • Protein Binding
  • Protein Structure, Tertiary*
  • Recombinant Fusion Proteins / metabolism
  • Sequence Alignment

Substances

  • Potassium Channels, Inwardly Rectifying
  • Recombinant Fusion Proteins