Non-selective cation channel activity of aquaporin AtPIP2;1 regulated by Ca2+ and pH
Caitlin S Byrt, Manchun Zhao, Mohamad Kourghi, Jayakumar Bose, Sam W. Henderson, Jiaen Qiu, Matthew Gilliham, Carolyn Schultz, Manuel Schwarz, Sunita A Ramesh, Andrea Yool and Steve Tyerman
Accepted manuscript online: 13 SEP 2016 03:15AM EST | DOI: 10.1111/pce.12832
The paradigm that aquaporins may only allow permeation of neutral solutes has been challenged by examples of some animal aquaporins that can act as ion channels. Here we reveal that AtPIP2;1 is permeable to both water and Na+ in heterologous systems. The AtPIP2;1 ionic conductance is inhibited by low pH and Ca2+ similar to previous observations for non-selective cation channels indicating that AtPIP2;1 is a candidate for facilitating Na+ flux across the plasma membrane of root cells and other cells that express PIP2;1, such as guard cells.