N-terminal arginines modulate plasma-membrane localization of Kv7.1/KCNE1 channel complexes

Zenawit Girmatsion, P. Biliczki, Ina Takac, Christin Schwerthelm, Stefan H. Hohnloser, Joachim R. Ehrlich

Research output: Contribution to journalArticle

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Abstract

Background and Objective: The slow delayed rectifier current (I Ks) is important for cardiac action potential termination. The underlying channel is composed of Kv7.1 α-subunits and KCNE1 β-subunits. While most evidence suggests a role of KCNE1 transmembrane domain and C-terminus for the interaction, the N-terminal KCNE1 polymorphism 38G is associated with reduced I Ks and atrial fibrillation (a human arrhythmia). Structure-function relationship of the KCNE1 N-terminus for I Ks modulation is poorly understood and was subject of this study. Methods: We studied N-terminal KCNE1 constructs disrupting structurally important positively charged amino-acids (arginines) at positions 32, 33, 36 as well as KCNE1 constructs that modify position 38 including an N-terminal truncation mutation. Experimental procedures included molecular cloning, patch-clamp recording, protein biochemistry, real-time-PCR and confocal microscopy. Results: All KCNE1 constructs physically interacted with Kv7.1. I Ks resulting from co-expression of Kv7.1 with non-atrial fibrillation '38S' was greater than with any other construct. Ionic currents resulting from co-transfection of a KCNE1 mutant with arginine substitutions ('38G-3xA') were comparable to currents evoked from cells transfected with an N-terminally truncated KCNE1-construct ('Δ1-38'). Western-blots from plasma-membrane preparations and confocal images consistently showed a greater amount of Kv7.1 protein at the plasma-membrane in cells co-transfected with the non-atrial fibrillation KCNE1-38S than with any other construct. Conclusions: The results of our study indicate that N-terminal arginines in positions 32, 33, 36 of KCNE1 are important for reconstitution of I Ks. Furthermore, our results hint towards a role of these N-terminal amino-acids in membrane representation of the delayed rectifier channel complex.

Original languageEnglish
Article numbere26967
JournalPLoS One
Volume6
Issue number11
DOIs
Publication statusPublished - Nov 4 2011

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Cell membranes
arginine
Arginine
plasma membrane
Cell Membrane
Amino Acids
Biochemistry
amino acids
Confocal microscopy
Cloning
arrhythmia
Clamping devices
Molecular Cloning
structure-activity relationships
transfection
action potentials
Polymorphism
Confocal Microscopy
biochemistry
Atrial Fibrillation

ASJC Scopus subject areas

  • Agricultural and Biological Sciences(all)
  • Biochemistry, Genetics and Molecular Biology(all)
  • Medicine(all)

Cite this

Girmatsion, Z., Biliczki, P., Takac, I., Schwerthelm, C., Hohnloser, S. H., & Ehrlich, J. R. (2011). N-terminal arginines modulate plasma-membrane localization of Kv7.1/KCNE1 channel complexes. PLoS One, 6(11), [e26967]. https://doi.org/10.1371/journal.pone.0026967

N-terminal arginines modulate plasma-membrane localization of Kv7.1/KCNE1 channel complexes. / Girmatsion, Zenawit; Biliczki, P.; Takac, Ina; Schwerthelm, Christin; Hohnloser, Stefan H.; Ehrlich, Joachim R.

In: PLoS One, Vol. 6, No. 11, e26967, 04.11.2011.

Research output: Contribution to journalArticle

Girmatsion, Z, Biliczki, P, Takac, I, Schwerthelm, C, Hohnloser, SH & Ehrlich, JR 2011, 'N-terminal arginines modulate plasma-membrane localization of Kv7.1/KCNE1 channel complexes', PLoS One, vol. 6, no. 11, e26967. https://doi.org/10.1371/journal.pone.0026967
Girmatsion, Zenawit ; Biliczki, P. ; Takac, Ina ; Schwerthelm, Christin ; Hohnloser, Stefan H. ; Ehrlich, Joachim R. / N-terminal arginines modulate plasma-membrane localization of Kv7.1/KCNE1 channel complexes. In: PLoS One. 2011 ; Vol. 6, No. 11.
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