| Western blotting using an antibody specific for the PKB / SGK1 consensus phosphorylation site in GSK3a / beta ( serine 21 and 9 respectively ) revealed an increase in GSK3a / beta phosphorylation in human embryonic kidney 293 ( HEK 293 ) cells overexpressing wild type SGK 1 , constitutively active SGK 1 , but not catalytically inactive SGK 1 . ^^^ |