SGK1

Serine/threonine-protein kinase Sgk1 ;
Serum/glucocorticoid-regulated kinase 1 ;

catalytic activity:ATP + a protein = ADP + a phosphoprotein. ,enzyme regulation:Two specific sites , one in the kinase domain (Thr-256) and the other in the C-terminal regulatory region (Ser-422) , need to be phosphorylated for its full activation. ,function:Protein kinase that plays an important role in cellular stress response. Activates certain potassium , sodium , and chloride channels , suggesting an involvement in the regulation of processes such as cell survival , neuronal excitability , and renal sodium excretion. Sustained high levels and activity may contribute to conditions such as hypertension and diabetic nephropathy. Mediates cell survival signals , phosphorylates and negatively regulates pro-apoptotic FOXO3A. Phosphorylates NEDD4L , which leads to its inactivation and to the subsequent activation of various channels and transporters such as ENaC , Kv1.3 , or EAAT1. ,induction:By serum and/or glucocorticoids. By excessive extracellular glucose and by TGF-beta , in cultured cells. ,PTM:Regulated by phosphorylation. Phosphoinositide 3-kinase (PI3-kinase) pathway promotes phosphorylation at Ser-422 which in turn increases the phosphorylation of Thr-256 by PDPK1. ,PTM:Ubiquitinated by NEDD4L; which promotes proteasomal degradation. Ubiquitinated by SYVN1 at the endoplasmic reticulum; which promotes rapid proteasomal degradation and maintains a high turnover rate in resting cells. ,similarity:Belongs to the protein kinase superfamily. AGC Ser/Thr protein kinase family. ,similarity:Contains 1 AGC-kinase C-terminal domain. ,similarity:Contains 1 protein kinase domain. ,subcellular location:Nuclear , upon phosphorylation. ,subunit:Interacts with NEDD4 and NEDD4L. ,tissue specificity:Expressed in most tissues with highest levels in the pancreas , followed by placenta , kidney and lung. ,

protein amino acid phosphorylation , phosphorus metabolic process , phosphate metabolic process , ion transport ,cation transport , sodium ion transport , apoptosis , cell death , programmed cell death , monovalent inorganic cation transport , death , phosphorylation , metal ion transport ,

Cytoplasm. Nucleus. Endoplasmic reticulum membrane. Cell membrane. Mitochondrion. The subcellular localization is controlled by the cell cycle , as well as by exposure to specific hormones and environmental stress stimuli. In proliferating cells , it shuttles between the nucleus and cytoplasm in synchrony with the cell cycle , and in serum/growth factor-stimulated cells it resides in the nucleus. In contrast , after exposure to environmental stress or treatment with glucocorticoids , it is detected in the cytoplasm and with certain stress conditions is associated with the mitochondria. In osmoregulation through the epithelial sodium channel , it can be localized to the cytoplasmic surface of the cell membrane. Nuclear , upon phosphorylation.; [Isoform 2]: Cell membrane.