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Single HERG delayed rectifier K+ channels expressed in Xenopus oocytes.
Am J Physiol. 1997 Mar; 272(3 Pt 2):H1309-14.AJ

Abstract

HERG is a K+ channel with properties similar to the rapidly activating component (I(Kr)) of delayed rectifier K+ current, which is important for repolarization of human cardiac myocytes. In this study, we have characterized the single-channel properties of HERG expressed in Xenopus oocytes. Currents were measured in cell-attached patches with an extracellular K concentration of 120 mM. The single HERG channel conductance, determined at test potentials between -50 and -110 mV, was 12.1 +/- 0.6 pS. At positive test potentials (+40 to +80 mV), the probability of channel opening was low and slope conductance was 5.1 +/- 0.6 pS. The mean channel open times at -90 mV were 2.9 +/- 0.5 and 11.8 +/- 1.0 ms, and the mean channel closed times were 0.54 +/- 0.02 and 14.5 +/- 5.3 ms. Single HERG channels were blocked by MK-499, a class III antiarrhythmic agent that blocks I(Kr) in cardiac myocytes. The development of block was more rapid in inside-out patches than in cell-attached patches or in whole cell recordings, indicating that block occurs from the cytoplasmic side of the membrane. The single-channel properties of HERG are similar to I(Kr) channels of isolated cardiac myocytes, which provides further evidence that HERG proteins coassemble to form I(Kr) channels.

Authors+Show Affiliations

Cardiology Division, University of Utah Health Sciences Center, Salt Lake City 84132, USA.No affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

9087606

Citation

Zou, A, et al. "Single HERG Delayed Rectifier K+ Channels Expressed in Xenopus Oocytes." The American Journal of Physiology, vol. 272, no. 3 Pt 2, 1997, pp. H1309-14.
Zou A, Curran ME, Keating MT, et al. Single HERG delayed rectifier K+ channels expressed in Xenopus oocytes. Am J Physiol. 1997;272(3 Pt 2):H1309-14.
Zou, A., Curran, M. E., Keating, M. T., & Sanguinetti, M. C. (1997). Single HERG delayed rectifier K+ channels expressed in Xenopus oocytes. The American Journal of Physiology, 272(3 Pt 2), H1309-14.
Zou A, et al. Single HERG Delayed Rectifier K+ Channels Expressed in Xenopus Oocytes. Am J Physiol. 1997;272(3 Pt 2):H1309-14. PubMed PMID: 9087606.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Single HERG delayed rectifier K+ channels expressed in Xenopus oocytes. AU - Zou,A, AU - Curran,M E, AU - Keating,M T, AU - Sanguinetti,M C, PY - 1997/3/1/pubmed PY - 1997/3/1/medline PY - 1997/3/1/entrez SP - H1309 EP - 14 JF - The American journal of physiology JO - Am J Physiol VL - 272 IS - 3 Pt 2 N2 - HERG is a K+ channel with properties similar to the rapidly activating component (I(Kr)) of delayed rectifier K+ current, which is important for repolarization of human cardiac myocytes. In this study, we have characterized the single-channel properties of HERG expressed in Xenopus oocytes. Currents were measured in cell-attached patches with an extracellular K concentration of 120 mM. The single HERG channel conductance, determined at test potentials between -50 and -110 mV, was 12.1 +/- 0.6 pS. At positive test potentials (+40 to +80 mV), the probability of channel opening was low and slope conductance was 5.1 +/- 0.6 pS. The mean channel open times at -90 mV were 2.9 +/- 0.5 and 11.8 +/- 1.0 ms, and the mean channel closed times were 0.54 +/- 0.02 and 14.5 +/- 5.3 ms. Single HERG channels were blocked by MK-499, a class III antiarrhythmic agent that blocks I(Kr) in cardiac myocytes. The development of block was more rapid in inside-out patches than in cell-attached patches or in whole cell recordings, indicating that block occurs from the cytoplasmic side of the membrane. The single-channel properties of HERG are similar to I(Kr) channels of isolated cardiac myocytes, which provides further evidence that HERG proteins coassemble to form I(Kr) channels. SN - 0002-9513 UR - https://www.unboundmedicine.com/medline/citation/9087606/Single_HERG_delayed_rectifier_K+_channels_expressed_in_Xenopus_oocytes_ L2 - https://journals.physiology.org/doi/10.1152/ajpheart.1997.272.3.H1309?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub=pubmed DB - PRIME DP - Unbound Medicine ER -