A novel GRAIL E3 ubiquitin ligase promotes environmental salinity tolerance in euryhaline tilapia

► Salinity stress induces Tilapia GRAIL mRNA and protein in gill epithelium. ► Tilapia GRAIL is highly expressed in gills and weakly in other tissues. ► Tilapia GRAIL is localized at the very tip of gill secondary lamellae. ► Tilapia GRAIL promotes cell survival in hyperosmotic media. ► Tilapia GRAIL suppresses programmed cell death (apoptosis) in hyperosmotic media.