Protein tyrosine phosphatase non-receptor type 12 negatively regulates cardiac HERG chan-nel currents
10.3969/j.issn.1673-4254.2013.12.02
- VernacularTitle:蛋白酪氨酸磷酸酶非受体型12负性调控心脏HERG钾通道电流
- Author:
Jijin LIN
1
;
Shukai LIU
;
Fangfang ZHENG
;
Qingyan MA
;
Hong YU
;
Li REN
;
Xinyuan SHEN
Author Information
1. 广东省心血管病研究所//广东省人民医院心内科
- Keywords:
long QT Syndrome;
HERG potassium channel;
protein tyrosine phosphatase non-receptor type 12;
patch-clamp technique
- From:
Journal of Southern Medical University
2013;(12):1718-1722
- CountryChina
- Language:Chinese
-
Abstract:
Objective To study the effect of protein tyrosine phosphatase non-receptor type 12 (PTPN12) in regulating cardiac HERG channel currents. Methods The plasmids pcDNA3.1-PTPN12-RFP and herg mutant constructed by PCR technique were transfected into HEK293 cells via Lipofectamine 2000, and the cells stably expressing PTPN12 selected with G418 were identified by Western blotting with anti-PTPN12 antibody. HERG channel current in cells expressing HERG alone (HEK293/HERG cells), cells overexpressing PTPN12 (HEK293/HERG cells transfected with pCDNA3.1-PTPN12-RFP), PAO-treated cells (PTPN12/HERG cells treated with PAO), and herg mutant cells (HEK293/HERGY327A-Y700A-Y845A cells transfected with pcDNA3.1-PTPN12-RFP) were recorded by patch-clamp technique. Results The plasmids pcDNA3.1-PTPN12-RFP and herg mutant were successfully constructed, and the stable expressing cell lines were established. Red fluorescence was obversed in HEK293/HERG cells transfected with pcDNA3.1- PTPN12- RFP, and the protein expression of PTPN12 was detected. Overexpression of PTPN12 significantly decreased HERG current density in HEK293/HERG cells, and this change was significantly weakened in the inhibitor group and herg mutant group. Conclusion PTPN12 negatively regulates cardiac HERG channel cerrent possibly by decreasing the phosphorylation level of HERG tyrosine residues. This finding provides further insight into the regulatory mechanism of HERG channel and the pathogenesis of long QT syndrome.
