GSBS Student Publications

Title

Secondary structure of a KCNE cytoplasmic domain

UMMS Affiliation

Graduate School of Biomedical Sciences; Department of Biochemistry and Molecular Pharmacology

Date

11-30-2006

Document Type

Article

Medical Subject Headings

Amino Acid Sequence; Animals; Cytoplasm; Humans; KCNQ1 Potassium Channel; Mutagenesis, Site-Directed; Patch-Clamp Techniques; Potassium Channels, Voltage-Gated; *Protein Structure, Secondary; Protein Structure, Tertiary; Xenopus laevis

Disciplines

Life Sciences | Medicine and Health Sciences

Abstract

Type I transmembrane KCNE peptides contain a conserved C-terminal cytoplasmic domain that abuts the transmembrane segment. In KCNE1, this region is required for modulation of KCNQ1 K(+) channels to afford the slowly activating cardiac I(Ks) current. We utilized alanine/leucine scanning to determine whether this region possesses any secondary structure and to identify the KCNE1 residues that face the KCNQ1 channel complex. Helical periodicity analysis of the mutation-induced perturbations in voltage activation and deactivation kinetics of KCNQ1-KCNE1 complexes defined that the KCNE1 C terminus is alpha-helical when split in half at a conserved proline residue. This helical rendering assigns all known long QT mutations in the KCNE1 C-terminal domain as protein facing. The identification of a secondary structure within the KCNE1 C-terminal domain provides a structural scaffold to map protein-protein interactions with the pore-forming KCNQ1 subunit as well as the cytoplasmic regulatory proteins anchored to KCNQ1-KCNE complexes.

Rights and Permissions

Citation: J Gen Physiol. 2006 Dec;128(6):721-9. Link to article on publisher's site

DOI of Published Version

10.1085/jgp.200609657

Related Resources

Link to Article in PubMed

Journal Title

The Journal of general physiology

PubMed ID

17130521