Transient receptor potential vanilloid 4 (TRP4) activation by arachidonic acid requires protein kinase A-mediated phosphorylation — Transient receptor potential vanilloid 4 (TRPV4) activation by arachidonic acid requires protein kinase A-mediated phosphorylation — Transient receptor potential vanilloid 4 (TRPV4) activation by arachidonic acid requires protein kinase A–mediated phosphorylation — Ser-824 phosphorylation regulates TRPV4 activation