Display Settings:

Format

Send to:

Choose Destination
    Science. 1990 Oct 26;250(4980):568-71.

    Restoration of inactivation in mutants of Shaker potassium channels by a peptide derived from ShB.

    Source

    Department of Molecular and Cellular Physiology, Stanford University School of Medicine, CA 94305.

    Abstract

    Site-directed mutagenesis experiments have suggested a model for the inactivation mechanism of Shaker potassium channels from Drosophila melanogaster. In this model, the first 20 amino acids form a cytoplasmic domain that interacts with the open channel to cause inactivation. The model was tested by the internal application of a synthetic peptide, with the sequence of the first 20 residues of the ShB alternatively spliced variant, to noninactivating mutant channels expressed in Xenopus oocytes. The peptide restored inactivation in a concentration-dependent manner. Like normal inactivation, peptide-induced inactivation was not noticeably voltage-dependent. Trypsin-treated peptide and peptides with sequences derived from the first 20 residues of noninactivating mutants did not restore inactivation. These results support the proposal that inactivation occurs by a cytoplasmic domain that occludes the ion-conducting pore of the channel.

    PMID:
    2122520
    [PubMed - indexed for MEDLINE]

      Supplemental Content

      Icon for HighWire Press

      Save items

      loading

      Recent activity

      Your browsing activity is empty.

      Activity recording is turned off.

      Turn recording back on

      See more...
      Write to the Help Desk