 | This article has multiple issues. Please helpimprove it or discuss these issues on thetalk page.(Learn how and when to remove these messages) (Learn how and when to remove this message)
|
Serine/threonine-protein kinases SGK represent a kinase subfamily withorthologs found across animalclades and in yeast[1] (compareTreefam family TF320906). In most vertebrates, including humans, there are three isoforms encoded by the genesSGK1,SGK2, andSGK3. The nameSerum/glucocorticoid-regulatedkinase refers to the first cloning of a SGK family member from a cDNA library screen for genes upregulated by the glucocorticoid dexamethasone in a rat mammary epithelial tumor cell line.[2]The first human family member (humanSGK1) was cloned in a screen of hepatocellular genes regulated in response to cellular hydration or swelling.[3]
The termSGK is also used as a synonym forSGK1.[4]
Among the three SGK genes, the SGK1 gene is the most intensively studied. This gene encodes aserine/threonine protein kinase that is highly similar to the rat serum-and glucocorticoid-induced protein kinase (SGK). This gene was identified in a screen of hepatocellular genes regulated in response to cellular hydration or swelling. Cellular hydration is acatabolic signal, stimulatingglycogenolysis andproteolysis, and inhibitingprotein andglycogen synthesis. This kinase has been shown to be important in activating certainpotassium,sodium, andchloride channels. Expression of this gene inhepatocytes is stimulated by transforming growth factor-beta (TGF-beta), which participates in the pathophysiology ofdiabetic complications. Since both TGF-beta expression and SGK expression are elevated indiabetic nephropathy, an involvement of SGK in the development of this condition is suggested.[4]
The SGK1 kinase regulates themyo-inositol transporter duringosmotic stress.[5]
Deregulated expression of SGK1 in the endometrium has been implicated in cases ofinfertility orrecurrent miscarriage in humans, and SGK1 expression in theendometrium also affects fertility in mice.[6]
