Referenced in: none

Automatically associated channels: Kv11.1

Title: [Protein tyrosine phosphatase non-receptor type 12 negatively regulates cardiac HERG channel currents].

Authors: Jijin Lin, Shukai Liu, Fangfang Zheng, Qingyan Ma, Hong Yu, Li Ren, Xinyuan Shen

Journal, date & volume: Nan Fang Yi Ke Da Xue Xue Bao, 2013 Dec , 33, 1718-22

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/24369231

Abstract
To study the effect of protein tyrosine phosphatase non-receptor type 12 (PTPN12) in regulating cardiac HERG channel currents.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.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.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.