Journal Club 19.05.10.

The TRPV4 Agonist GSK1016790A Regulates the Membrane Expression of TRPV4 Channels

The TRPV4 Agonist GSK1016790A Regulates the Membrane Expression of TRPV4 Channels

Sara Baratchi1*, Peter Keov1,2,3, William G. Darby1, Austin Lai1, Khashayar Khoshmanesh4, Peter Thurgood4, Parisa Vahidi1, Karin Ejendal5 and Peter McIntyre1
1 School of Health and Biomedical Sciences, RMIT University, Melbourne, VIC, Australia, 2 Molecular Pharmacology Division, Victor Chang Cardiac Research Institute, Darlinghurst, NSW, Australia, 3 St Vincent’s Clinical School, University of New South Wales, Darlinghurst, NSW, Australia, 4 School of Engineering, RMIT University, Melbourne, VIC, Australia, 5 Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States

TRPV4 is a non-selective cation channel that tunes the function of different tissues including the vascular endothelium, lung, chondrocytes, and neurons. GSK1016790A is the selective and potent agonist of TRPV4 and a pharmacological tool that is used to study the TRPV4 physiological function in vitro and in vivo. It remains unknown how the sensitivity of TRPV4 to this agonist is regulated. The spatial and temporal dynamics of receptors are the major determinants of cellular responses to stimuli. Membrane translocation has been shown to control the response of several members of the transient receptor potential (TRP) family of ion channels to different stimuli. Here, we show that TRPV4 stimulation with GSK1016790A caused an increase in [Ca2+]i that is stable for a few minutes. Single molecule analysis of TRPV4 channels showed that the density of TRPV4 at the plasma membrane is controlled through two modes of membrane trafficking, complete, and partial vesicular fusion. Further, we show that the density of TRPV4 at the plasma membrane decreased within 20min, as they translocate to the recycling endosomes and that the surface density is dependent on the release of calcium from the intracellular stores and is controlled via a PI3K, PKC, and RhoA signaling pathway.
Keywords: TRPV4, membrane trafficking, endothelial cells, GSK1016790A, calcium