Targeting of calcineurin to an NFAT-like docking site is required for the calcium-dependent activation of the background K+ channel, TRESK

Research output: Contribution to journalArticle

76 Citations (Scopus)


The two-pore domain K+ channel, TRESK (TWIK-related spinal cord K+ channel) is activated in response to the calcium signal by the calcium/calmodulin-dependent protein phosphatase, calcineurin. In the present study we report that calcineurin also interacts with TRESK via an NFAT-like docking site, in addition to its enzymatic action. In its intracellular loop, mouse TRESK possesses the amino acid sequence, PQIVID, which is similar to the calcineurin binding consensus motif, PXIXIT (where X denotes any amino acids), necessary for NFAT (nuclear factor of activated T cells) activation and nuclear translocation. Mutations of the PQIVID sequence of TRESK to PQIVIA, PQIVAD, or PQAVAD increasingly deteriorated the calcium-dependent activation in the listed order and correspondingly reduced the benzocaine sensitivity (a property discriminating activated channels from resting ones), when it was measured after the calcium signal in Xenopus oocytes. Microinjection of VIVIT peptide, designed to inhibit the NFAT-calcineurin interaction specifically, also eliminated TRESK activation. The intracellular loop of TRESK, expressed as a GST fusion protein, bound constitutively active calcineurin in vitro. PQAVAD mutation as well as addition of VIVIT peptide to the reaction abrogated this calcineurin binding. Wild type calcineurin was recruited to GST-TRESK-loop in the presence of calcium and calmodulin. These results indicate that the PQIVID sequence is a docking site for calcineurin, and its occupancy is required for the calcium-dependent regulation of TRESK. Immunosuppressive compounds, developed to target the NFAT binding site of calcineurin, are also expected to interfere with TRESK regulation, in addition to their desired effect on NFAT.

Original languageEnglish
Pages (from-to)14677-14682
Number of pages6
JournalJournal of Biological Chemistry
Issue number21
Publication statusPublished - May 26 2006

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

Fingerprint Dive into the research topics of 'Targeting of calcineurin to an NFAT-like docking site is required for the calcium-dependent activation of the background K<sup>+</sup> channel, TRESK'. Together they form a unique fingerprint.

  • Cite this