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Co-expression of KCNE2 and KChIP2c modulates the electrophysiological properties of Kv4.2 current in COS-7 cells.
Acta Pharmacol Sin. 2008 Jun; 29(6):653-60.AP

Abstract

AIM

Several beta-subunits have been suggested to modulate the electrophysiological properties of the transient outward current (I(to)) in cardiac myocytes, including the obligatory beta-subunit K+-channel interacting protein (KChIP2) and KCNE2. However, neither KChIP2 nor KCNE2 modulation of Kv4.x (x=2 and/or 3) can fully recapitulate the electrophysiological properties of native I(to). The present study is to investigate how I(to) current is modulated when both KChIP2 and KCNE2 are coexpressed.

METHODS

Kv4.2, KChIP2c, and KCNE2 cDNA were simultaneously transfected into COS-7 cells at a molar ratio of 3:1:1. Whole-cell currents were recorded by the patch-clamp method.

RESULTS

In comparison with the current regulated by KChIP2c alone, the co-expression of KCNE2 further slowed Kv4.2 current inactivation kinetics, but diminished KChIP2c-induced positive shift of the voltage-dependent activation of Kv4.2 current. Importantly, co-expression of KCNE2 accelerated the current recovery from inactivation, and caused an povershootq of peak current amplitude during Kv4.2 current recovery, a phenomenon which has been uniquely described for human I(to). However, co-expression of KCNE2 exerted no further effect on Kv4.2 current amplitude, the rate of Kv4.2 current activation and voltage-dependent inactivation.

CONCLUSION

Co-expression of Kv4.2 with KChIP2c and KCNE2, but not with KChIP2c or KCNE2 alone, yields a current profile similar to native I(to). Both KChIP2c and KCNE2 simultaneously participate in recapitulation of the electrophysiological properties of I(to) in cardiac myocytes.

Authors+Show Affiliations

Department of Pathophysiology, Southern Medical University, Guangzhou 510515, China.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

18501111

Citation

Liu, Wen-juan, et al. "Co-expression of KCNE2 and KChIP2c Modulates the Electrophysiological Properties of Kv4.2 Current in COS-7 Cells." Acta Pharmacologica Sinica, vol. 29, no. 6, 2008, pp. 653-60.
Liu WJ, Wang HT, Chen WW, et al. Co-expression of KCNE2 and KChIP2c modulates the electrophysiological properties of Kv4.2 current in COS-7 cells. Acta Pharmacol Sin. 2008;29(6):653-60.
Liu, W. J., Wang, H. T., Chen, W. W., Deng, J. X., Jiang, Y., & Liu, J. (2008). Co-expression of KCNE2 and KChIP2c modulates the electrophysiological properties of Kv4.2 current in COS-7 cells. Acta Pharmacologica Sinica, 29(6), 653-60. https://doi.org/10.1111/j.1745-7254.2008.00804.x
Liu WJ, et al. Co-expression of KCNE2 and KChIP2c Modulates the Electrophysiological Properties of Kv4.2 Current in COS-7 Cells. Acta Pharmacol Sin. 2008;29(6):653-60. PubMed PMID: 18501111.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Co-expression of KCNE2 and KChIP2c modulates the electrophysiological properties of Kv4.2 current in COS-7 cells. AU - Liu,Wen-juan, AU - Wang,Hai-tang, AU - Chen,Wei-wei, AU - Deng,Jian-xin, AU - Jiang,Yong, AU - Liu,Jie, PY - 2008/5/27/pubmed PY - 2009/4/25/medline PY - 2008/5/27/entrez SP - 653 EP - 60 JF - Acta pharmacologica Sinica JO - Acta Pharmacol Sin VL - 29 IS - 6 N2 - AIM: Several beta-subunits have been suggested to modulate the electrophysiological properties of the transient outward current (I(to)) in cardiac myocytes, including the obligatory beta-subunit K+-channel interacting protein (KChIP2) and KCNE2. However, neither KChIP2 nor KCNE2 modulation of Kv4.x (x=2 and/or 3) can fully recapitulate the electrophysiological properties of native I(to). The present study is to investigate how I(to) current is modulated when both KChIP2 and KCNE2 are coexpressed. METHODS: Kv4.2, KChIP2c, and KCNE2 cDNA were simultaneously transfected into COS-7 cells at a molar ratio of 3:1:1. Whole-cell currents were recorded by the patch-clamp method. RESULTS: In comparison with the current regulated by KChIP2c alone, the co-expression of KCNE2 further slowed Kv4.2 current inactivation kinetics, but diminished KChIP2c-induced positive shift of the voltage-dependent activation of Kv4.2 current. Importantly, co-expression of KCNE2 accelerated the current recovery from inactivation, and caused an povershootq of peak current amplitude during Kv4.2 current recovery, a phenomenon which has been uniquely described for human I(to). However, co-expression of KCNE2 exerted no further effect on Kv4.2 current amplitude, the rate of Kv4.2 current activation and voltage-dependent inactivation. CONCLUSION: Co-expression of Kv4.2 with KChIP2c and KCNE2, but not with KChIP2c or KCNE2 alone, yields a current profile similar to native I(to). Both KChIP2c and KCNE2 simultaneously participate in recapitulation of the electrophysiological properties of I(to) in cardiac myocytes. SN - 1745-7254 UR - https://www.unboundmedicine.com/medline/citation/18501111/Co_expression_of_KCNE2_and_KChIP2c_modulates_the_electrophysiological_properties_of_Kv4_2_current_in_COS_7_cells_ L2 - https://doi.org/10.1111/j.1745-7254.2008.00804.x DB - PRIME DP - Unbound Medicine ER -