Open AccessImpact of phosphomimetic and non‐phosphorylatable mutations of phospholemman on L‐type calcium channels gating in HEK 293T cells
Author(s) -
Guo Kai,
Wang YuePeng,
Zhou ZhiWen,
Jiang YiBo,
Li Wei,
Chen XiaoMeng,
Li YiGang
Publication year - 2015
Publication title -
journal of cellular and molecular medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.44
H-Index - 130
eISSN - 1582-4934
pISSN - 1582-1838
DOI - 10.1111/jcmm.12484
Subject(s) - hek 293 cells , phosphorylation , gating , mutant , transfection , wild type , chemistry , voltage dependent calcium channel , kinase , microbiology and biotechnology , calcium , biophysics , biology , biochemistry , gene , organic chemistry
Background : Phospholemman ( PLM ) is an important phosphorylation substrate for protein kinases A and C in the heart. Until now, the association between PLM phosphorylation status and L‐type calcium channels ( LTCC s) gating has not been fully understood. We investigated the kinetics of LTCC s in HEK 293T cells expressing phosphomimetic or nonphosphorylatable PLM mutants. Methods : The LTCC s gating was measured in HEK 293T cells transfected with LTCC and wild‐type ( WT ) PLM , phosphomimetic or nonphosphorylatable PLM mutants: 6263 AA , 6869 AA , AAAA , 6263 DD , 6869 DD or DDDD . Results : WT PLM significantly slowed LTCC s activation and deactivation while enhanced voltage‐dependent inactivation ( VDI ). PLM mutants 6869 DD and DDDD significantly increased the peak of the currents. 6263 DD accelerated channel activation, while 6263 AA slowed it more than WT PLM . 6869 DD significantly enhanced PLM ‐induced increase of VDI . AAAA slowed the channel activation more than 6263 AA , and DDDD accelerated the channel VDI more than 6869 DD . Conclusions : Our results demonstrate that phosphomimetic PLM could stimulate LTCC s and alter their dynamics, while PLM nonphosphorylatable mutant produced the opposite effects.