Open AccessCaMKII Potentiates Store-Operated Ca2+ Entry Through Enhancing STIM1 Aggregation and Interaction with Orai1
Author(s) -
Shu Li,
Jingyi Xue,
Zhuo Sun,
Tiantian Liu,
Lane Zhang,
Limin Wang,
Hongjie You,
Fan Zheng,
Yuanyuan Zheng,
Di Luo
Publication year - 2018
Publication title -
cellular physiology and biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.486
H-Index - 87
eISSN - 1421-9778
pISSN - 1015-8987
DOI - 10.1159/000488835
Subject(s) - orai1 , stim1 , microbiology and biotechnology , chemistry , gene knockdown , crosstalk , thapsigargin , immunoprecipitation , hek 293 cells , biology , extracellular , endoplasmic reticulum , biochemistry , receptor , apoptosis , physics , gene , optics
Background/Aims: Upon Ca2+ store depletion, stromal interaction molecule 1 (STIM1) oligomerizes, redistributes near plasmalemma to interact with Ca2+ selective channel-forming subunit (Orai1) and initiates store-operated Ca2+ entry (SOCE). Ca2+/calmodulin-dependent protein kinase II (CaMKII) is a regulator of SOCE, but how CaMKII regulates SOCE remains obscure. Methods: Using Fura2, confocal microscopy, co-immunoprecipitation, specific blocker and overexpression/knockdown approaches, we evaluated STIM1 aggregation and its interaction with Orai1, and SOCE upon Ca2+ store depletion in thapsigargin (TG) treated HEK293 and HeLa cells. Results: Overexpression of CaMKIIδ enhanced TG-induced STIM1 co-localization and interaction with Orai1 as well as SOCE. In contrast, CaMKIIδ knockdown and a specific inhibitor of CaMKII suppressed them. In addition, overexpression or knockdown of CaMKIIδ in TG treated cells exhibited increased or reduced STIM1 clustering and plasmalemma redistribution, respectively. Conclusion: CaMKII up-regulates SOCE by increasing STIM1 aggregation and interaction with Orai1. This study provides an additional insight into SOCE regulation and a potential mechanism for CaMKII involvement in some pathological situations through crosstalk with SOCE.