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AQP2 can modulate the pattern of Ca 2+ transients induced by store‐operated Ca 2+ entry under TRPV4 activation
Author(s) -
Pizzoni Alejandro,
López González Macarena,
Di Giusto Gisela,
Rivarola Valeria,
Capurro Claudia,
Ford Paula
Publication year - 2018
Publication title -
journal of cellular biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.028
H-Index - 165
eISSN - 1097-4644
pISSN - 0730-2312
DOI - 10.1002/jcb.26612
Subject(s) - intracellular , trpv4 , hyperpolarization (physics) , microbiology and biotechnology , chemistry , aquaporin 2 , aquaporin , biophysics , potassium channel , membrane potential , extracellular , aquaporin 3 , ion channel , biochemistry , biology , receptor , water channel , mechanical engineering , organic chemistry , nuclear magnetic resonance spectroscopy , engineering , inlet
There is increasing evidence indicating that aquaporins (AQPs) exert an influence in cell signaling by the interplay with the TRPV4 Ca 2+ channel. Ca 2+ release from intracellular stores and plasma membrane hyperpolarization due to opening of Ca 2+ ‐activated potassium channels (KCa) are events that have been proposed to take place downstream of TRPV4 activation. A major mechanism for Ca 2+ entry, activated after depletion of intracellular Ca 2+ stores and driven by electrochemical forces, is the store‐operated Ca 2+ entry (SOCE). The consequences of the interplay between TRPV4 and AQPs on SOCE have not been yet investigated. The aim of our study was to test the hypothesis that AQP2 can modulate SOCE by facilitating the interaction of TRPV4 with KCa channels in renal cells. Using fluorescent probe techniques, we studied intracellular Ca 2+ concentration and membrane potential in response to activation of TRPV4 in two rat cortical collecting duct cell lines (RCCD 1 ), one not expressing AQPs (WT‐RCCD 1 ) and the other transfected with AQP2 (AQP2‐RCCD 1 ). We found that AQP2 co‐immunoprecipitates with TRPV4 and with the small‐conductance potassium channel (SK3). We also showed that AQP2 is crucial for the activation of SK3 by TRPV4, leading to hyperpolarization of the plasma membrane. This seems to be relevant to modulate the magnitude of SOCE and is accompanied by TRPV4 translocation to the plasma membrane only in AQP2 expressing cells. These findings open the perspective to further investigate whether the interplay between different AQPs with TRPV4 and KCa channels can be an important mechanism to modulate SOCE with physiological relevance.