Truncated K+ channel DNA sequences specifically suppress lymphocyte K+ channel gene expression

  • Tu L
  • Santarelli V
  • Deutsch C
  • 8


    Mendeley users who have this article in their library.
  • 38


    Citations of this article.


We have constructed a series of deletion mutants of Kv1.3, a Shaker-like, voltage-gated K+ channel, and examined the ability of these truncated mutants to form channels and to specifically suppress full-length Kv1.3 currents. These constructs were expressed heterologously in both Xenopus oocytes and a mouse cytotoxic T cell line. Our results show that a truncated mutant Kv1.3 must contain both the amino terminus and the first transmembrane-spanning segment, S1, to suppress full-length Kv1.3 currents. Amino-terminal-truncated DNA sequences from one subfamily suppress K+ channel expression of members of only the same subfamily. The first 141 amino acids of the amino-terminal of Kv1.3 are not necessary for channel formation. Deletion of these amino acids yields a current identical to that of full-length Kv1.3, except that it cannot be suppressed by a truncated Kv1.3 containing the amino terminus and S1. To test the ability of truncated Kv1.3 to suppress endogenous K+ currents, we constructed a plasmid that contained both truncated Kv1.3 and a selection marker gene (mouse CD4). Although constitutively expressed K+ currents in Jurkat (a human T cell leukemia line) and GH3 (an anterior pituitary cell line) cells cannot be suppressed by this double-gene plasmid, stimulated (up-regulated) Shaker-like K+ currents in GH3 cells can be suppressed. © 1995, The Biophysical Society. All rights reserved.

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document


  • L. Tu

  • V. Santarelli

  • C. Deutsch

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free