JCI - A missense mutation in the Kv1.1 voltage-gated potassium channel–encoding gene KCNA1 is linked to human autosomal dominant hypomagnesemia

A missense mutation in the Kv1.1 voltage-gated potassium channel–encoding gene KCNA1 is linked to human autosomal dominant hypomagnesemia

Bob Glaudemans, Jenny van der Wijst, Rosana H. Scola, Paulo J. Lorenzoni, Angelien Heister, AnneMiete W. van der Kemp, Nine V. Knoers, Joost G. Hoenderop, René J. Bindels

Published in Volume 119, Issue 4

J Clin Invest. 2009; 119(4):936–942 doi:10.1172/JCI36948

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Figure 3

Electrophysiological analysis of HEK293 cells transfected with mock plasmid, wild-type Kv1.

(Kv1.1 WT), or Kv1.1 N255D. (A) Representative original traces of outward K⁺ currents of cells transfected with mock plasmid, Kv1.1 WT, Kv1.1 N255D, or Kv1.1 WT and mock plasmid elicited by voltage steps from –100 to +50 mV in 10-mV increments, applied from a holding potential of –80 mV, every 10 seconds. (B) The I-V relationships of cells transfected with mock plasmid (circles, n = 5), Kv1.1 WT (squares, n = 11), Kv1.1 N255D (triangles, n = 10), and Kv1.1 WT and mock plasmid (diamonds, n = 9). (C) Histogram presenting averaged current densities at +50 mV of cells transfected with mock plasmid (n = 5), Kv1.1 WT (n = 11), Kv1.1 WT and mock plasmid (n = 9), Kv1.1 WT and Kv1.1 N255D (n = 9), and Kv1.1 N255D (n = 10). *P < 0.05, compared with mock; ^#P < 0.05, compared with Kv1.1 WT. (D) Cell surface biotinylation of HEK293 cells transfected with mock plasmid, Kv1.1 WT, Kv1.1 WT and mock plasmid, Kv1.1 WT and Kv1.1 N255D, and Kv1.1 N255D. Kv1.1 expression was analyzed by immunoblotting for plasma membrane fraction (PM) and input from the total cell lysates (IP). Representative immunoblot of 4 independent experiments is shown. (E) Histogram presenting averaged current densities at +80 mV after 200 seconds of cells cotransfected with TRPM6 and mock plasmid (n = 26), TRPM6 and Kv1.1 WT (n = 26), and TRPM6 and Kv1.1 N255D (n = 25). (F) Membrane potential of cells transfected with mock plasmid, Kv1.1 WT, and Kv1.1 N255D upon acute application of DTX-K (10 nM), measured in current clamp mode of whole-cell patch clamp configuration. Representative recordings of 8 independent experiments are shown. The error bars denote SEM.