The serum- and glucocorticoid-induced protein kinase-1 (Sgk-1) mitochondria connection: Identification of the IF-1 inhibitor of the F1F0-ATPase as a mitochondria-specific binding target and the stress-induced mitochondrial localization of endogenous Sgk-1

► Cell stress response triggers expression of a mitochondria localized protein kinase. ► IF-1 is the first established mitochondria target for Sgk-1. ► Sgk-1 interaction with IF-1 is a new potential cell survival response to stress. ► Sgk-1 can directly phosphorylate F1F0-ATPase in an in vitro assay.